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Overview of the brain’s anatomy

The brain is the most complex organ in the human body. It produces our every thought, action, memory, feeling and experience of the world. This jelly-like mass of tissue, weighing in at around 1.4 kilograms in an adult, contains a staggering one hundred billion nerve cells, or neurons.The brain and spinal cord together form the central nervous system (CNS).

The complexity of the connectivity between these cells is mind-boggling. Each neuron can make contact with thousands or even tens of thousands of others, via tiny structures called synapses. Our brains form a million new connections for every second of our lives. The pattern and strength of the connections is constantly changing and no two brains are alike.

The neurons in our brains communicate in a variety of ways. Signals pass between them by the release of neurotransmitter and neuromodulator chemicals, such as glutamate, dopamine, acetylcholine, noradrenalin, serotonin, and endorphins.

Some neurochemicals work in the synapse, passing specific messages from release sites to collection sites, called receptors. Others also spread their influence more widely, like a radio signal, making whole brain regions more or less sensitive.

These neurochemicals are so important that deficiencies in them are linked to certain diseases. For example, a loss of dopamine in the basal ganglia, which controls movements, leads to Parkinson’s disease. It can also increase susceptibility to addiction because it mediates our sensations of reward and pleasure.

Similarly, a deficiency in serotonin, used by regions involved in emotion, can be linked to depression or mood disorders, and the loss of acetylcholine in the cerebral cortex is characteristic of Alzheimer’s disease.

The brain is made up of multiple parts, and each part of the brain is responsible for different body functions. Therefore, brain tumor symptoms depend a great deal on where the tumor is located. Major parts of the brain: There are three major parts of the brain.

Cerebrum: uses information from senses to tell our body how to respond. It controls reading, thinking, learning, movement, speech, vision, personality and emotions.
Cerebellum: controls balance for standing, walking and other motion.
Brain stem: connects the brain with the spinal cord and controls basic body functions such as breathing, sleeping, body temperature and blood pressure.

It is protected by:

Brain Vasulature

Brain Fibers

Skull

The skull is a bone structure that forms the head in vertebrates. It supports the structures of the face and provides a protective cavity for the brain. The skull is composed of two parts: the cranium and the mandible.

Injuries to the brain can be life-threatening. Normally the skull protects the brain from damage through its hard unyieldingness; the skull is one of the least deformable structures found in nature with it needing the force of about 1 ton to reduce the diameter of the skull by 1 cm.

Cranial Nerves

Your cranial nerves are pairs of nerves that connect your brain to different parts of your head, neck, and trunk. There are 12 of them, each named for their function or structure.

Each nerve also has a corresponding Roman numeral between I and XII. This is based off their location from front to back. For example, your olfactory nerve is closest to the front of your head, so it’s designated as I.

Their functions are usually categorized as being either sensory or motor. Sensory nerves are involved with your senses, such as smell, hearing, and touch. Motor nerves control the movement and function of muscles or glands.

Olfactory nerve

The olfactory nerve transmits sensory information to your brain regarding smells that you encounter.

Optic nerve

The optic nerve is the sensory nerve that involves vision.

Oculomotor nerve

The oculomotor nerve has two different motor functions: muscle function and pupil response.

Muscle function.Your oculomotor nerve provides motor function to four of the six muscles around your eyes. These muscles help your eyes move and focus on objects.
Pupil response.It also helps to control the size of your pupil as it responds to light.

This nerve originates in the front part of your midbrain, which is a part of your brainstem. It moves forward from that area until it reaches the area of your eye sockets.

Trochlear nerve

The trochlear nerve controls your superior oblique muscle. This is the muscle that’s responsible for downward, outward, and inward eye movements.

Trigeminal nerve

The trigeminal nerve is the largest of your cranial nerves and has both sensory and motor functions.

The trigeminal nerve has three divisions, which are:

Ophthalmic. The ophthalmic division sends sensory information from the upper part of your face, including your forehead, scalp, and upper eyelids.
Maxillary. This division communicates sensory information from the middle part of your face, including your cheeks, upper lip, and nasal cavity.
Mandibular. The mandibular division has both a sensory and a motor function. It sends sensory information from your ears, lower lip, and chin. It also controls the movement of muscles within your jaw and ear.

Abducens nerve

The abducens nerve controls another muscle that’s associated with eye movement, called the lateral rectus muscle. This muscle is involved in outward eye movement. For example, you would use it to look to the side.

Facial nerve

The facial nerve provides both sensory and motor functions, including:

moving muscles used for facial expressions as well as some muscles in your jaw
providing a sense of taste for most of your tongue
supplying glands in your head or neck area, such as salivary glands and tear-producing glands
communicating sensations from the outer parts of your ear

Vestibulocochlear nerve

Your vestibulocochlear nerve has sensory functions involving hearing and balance. It consists of two parts, the cochlear portion and vestibular portion:

Cochlear portion. Specialized cells within your ear detect vibrations from sound based off of the sound’s loudness and pitch. This generates nerve impulses that are transmitted to the cochlear nerve.
Vestibular portion. Another set of special cells in this portion can track both linear and rotational movements of your head. This information is transmitted to the vestibular nerve and used to adjust your balance and equilibrium.

Glossopharyngeal nerve

The glossopharyngeal nerve has both motor and sensory functions, including:

sending sensory information from your sinuses, the back of your throat, parts of your inner ear, and the back part of your tongue
providing a sense of taste for the back part of your tongue
stimulating voluntary movement of a muscle in the back of your throat called the stylopharyngeus

Vagus nerve

The vagus nerve is a very diverse nerve. It has both sensory and motor functions, including:

communicating sensation information from your ear canal and parts of your throat
sending sensory information from organs in your chest and trunk, such as your heart and intestines
allowing motor control of muscles in your throat
stimulating the muscles of organs in your chest and trunk, including those that move food through your digestive tract (peristalsis)
providing a sense of taste near the root of your tongue

Out of all of the cranial nerves, the vagus nerve has the longest pathway. It extends from your head all the way into your abdomen.

Accessory nerve

Your accessory nerve is a motor nerve that controls the muscles in your neck. These muscles allow you to rotate, flex, and extend your neck and shoulders.

It’s divided into two parts: spinal and cranial. The spinal portion originates in the upper part of your spinal cord. The cranial part starts in your medulla oblongata.

These parts meet briefly before the spinal part of the nerve moves to supply the muscles of your neck while the cranial part follows the vagus nerve.

Hypoglossal nerve

Your hypoglossal nerve is the 12th cranial nerve which is responsible for the movement of most of the muscles in your tongue. It starts in the medulla oblongata and moves down into the jaw, where it reaches the tongue.

SPINE

The spine, or backbone, is the body’s central support structure. It connects different parts of your musculoskeletal system. Your spine helps you sit, stand, walk, twist and bend. Back injuries, spinal cord conditions and other problems can damage the spine and cause back pain.

The human spine is a complex anatomic structure that is the scaffolding for the entire body. It provides several important functions, including:

Protecting the spinal cord and nerves
Structural support for the body, allowing us to stand upright. The spine supports about half the weight of the body.

The average person is born with 33 individual bones (the vertebrae) that interact and connect with each other through flexible joints called facets.

By the time a person becomes an adult most have only 24 vertebrae because some vertebrae at the bottom end of the spine fuse together during normal growth and development.

The bottom of the spine is called the sacrum. It is made up of several vertebral bodies usually fused together as one. The remaining small bones or ossicles below the sacrum are also fused together and called the tailbone or coccyx. The spine above the sacrum consists of:

Seven bones in the neck—the cervical spine
12 bones in the chest—the thoracic spine
Five bones in the lower back—the lumbar spine

The spinal column combines strong bones, unique joints, flexible ligaments and tendons, large muscles, and highly sensitive nerves.

Difference Between Neurologists And Neurosurgerons

Neurology is the medical specialty focusing on the diagnosis and treatment of conditions that affect the brain and nervous system, as well as the spinal cord, blood vessels, muscles, and nerves. These conditions are treated by physicians in two related specialties: neurology and neurosurgery.

So why is there a distinction of neurologist vs. neurosurgeon?

There are considerable differences between neurologists and neurosurgeons. When it comes to medical management, however, there is also significant overlap between the two. While both neurologists and neurosurgeons diagnose and treat conditions that involve the nervous system, neurologists don’t perform surgery.

Neurosurgery is closely associated with neurology in that both require specialized knowledge of the nervous system and its functions. However, if your diagnosis exposes a physical cause for a neurological condition, a neurologist may make a referral to a neurosurgeon if surgery is needed to remove or correct the condition to improve your outcome.

What Is Neuromedicine?
Neuromedicine describes a practice where neurosurgeons, neurologists, and other medical professionals work together to provide comprehensive inpatient care for patients with complex neurological disorders.

How neurosurgery has changed in the last 50 years, what has contributed to it?

Neurosurgery In The Beginning

The brain is the centre-point of communication between the human being and the universe. It defines consciousness which is an integral part of human evolution, from which arise inventions and discoveries. The study of the human brain has always been challenging. The functions of a large portion of the brain are still poorly understood and unexplored.

The history of neurosurgery is filled with courageous individuals who worked against great odds in an attempt to improve the lives of their patients. For centuries, the realm of neurosurgery was considered an arena mostly of observation and “primum non nocere,” as surgical outcomes were often worse than disease progression. The next few centuries witnessed great advances in anatomical knowledge, but until further developments in the areas of cerebral localization, anesthesia, hemostasis, and antisepsis occurred, neurosurgery remained in its infancy.

Our pioneers fought against all odds during those times to deliver the best possible. Constant quest to develop better, in terms of understanding of the brain and technology brought us to where we stand today.

In The Past: First Cut, And Then Diagnose

Neurosurgery, a new subspecialty, is constantly evolving and changing over a period of time. In recent times, new insights and requirements in terms of knowledge and practice, sub-specialisation among consultants and use of multidisciplinary teams of neurologists, neurosurgeons, radiologists, anaesthesiologists, and pathologists are involved to tackle neurological problems. In recent years, newer advanced technologies have expanded and redefined the discipline of neurosurgery.

Present: First Diagnose And Then Cut

Combinning Modalities

Neurosurgery, depends upon technologies. Some of the technologies are completely new and others have undergone a lot of reforms to reach their present state. Although revolution has been brought by the use of CT scans, recent advances like intraoperative ultrasonography, stereotactic radiosurgery, use of stem cells, Deep Brain Stimulation (DBS), can possibly change the face of neurosurgery in future.

Technological advances are transforming our diagnostic, monitoring and management capabilities and allowing us to perform more precise, advanced, and less invasive surgeries. Developments in computers, smartphones and connectivity devices, education, imaging and localization; surgical targeting and navigation; new therapeutic applications; and neurological monitoring, and analytics have rapidly and dramatically changed our approaches within the specialty of neurosurgery

How Things Are Different Today?

Better Understanding Of The Brain Connection And Functions

Functional MRI

Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases.

Physicians use fMRI to assess how risky brain surgery or similar invasive treatment is for a patient and to learn how a normal, diseased or injured brain is functioning. They map the brain with fMRI to identify regions linked to critical functions such as speaking, moving, sensing, or planning. This is useful to plan for surgery and radiation therapy of the brain. Clinicians also use fMRI to anatomically map the brain and detect the effects of tumors, stroke, head and brain injury, or diseases such as Alzheimer’s, and developmental disabilities such as Autism etc

Better Understanding Of Tumour Relations To Brain Structures

Better Neuromonitoring During Surgery

Newer Techniques

1.Stereotactic radiosurgery:

Stereotactic radiotherapy, where highly focused gamma or X rays beams converge on the tumor and deliver highly focused radiation directed solely to the tumor.

Not long ago, patients who had a pituitary tumor, acoustic neuroma, or meningioma had limited treatment options: undergo a traditional craniotomy to remove the tumor, followed by fractionated radiation. Traditional radiation typically is delivered to the tumor and surrounding tissue, which can lead to hair loss, damage to healthy tissue, and skin changes.

Stereotactic radiosurgery changed all that. Two of the better-known types are CyberKnife and GammaKnife. Stereotactic approaches deliver highly focused radiation directed solely to the tumor, which spares more healthy tissue and markedly reduces side effects. Perhaps the biggest benefit is that treatment usually can be completed in just one session, saving patients time and the hassle of traveling.

It can be used in the treatment of various types of brain tumors, AVMs, and /or trigeminal neuralgia and tremors. Most of the skull base tumors are intimately associated with critical nervous and vascular structures. Radiosurgery in such complex tumors has become an increasingly attractive adjuvant to microsurgical resection of the lesion at the skull base.

2. Minimally Invasive Neurosurgery (MIN)

What Is Minimally Invasive Surgery?
It is a surgery in which the operation’s impact is minimized by reducing the incision size as well as the size of the instrument used to carry out the procedure

The field of surgery is being redefined by Minimal invasive surgery (MIS). Several surgeries, as well as diagnostic procedures, are described by this term. A surgeon needs to make a big incision in traditional surgeries in order to operate. Through MIS, the surgeon makes a few tiny holes – normally less than half an inch. After that, he inserts specially designed (Endoscopes), fine instruments, and advanced video equipment to carry out the operation through the smaller openings. Tumors that are large can be removed as well through small openings (micro craniotomy). Neurosurgeons use minimally invasive surgery. Non-invasive treatments are used by neurosurgeons whenever these techniques can achieve equivalent or better results in comparison to standard open surgical procedures. Sophisticated minimally invasive neuro navigation technology minimizes incisions frequently allowing surgeons to cosmetically hide scars.

a) Micro Craniotomy

The surgical removal of fragment of the bone from the skull for exposing the brain is called craniotomy. The part of bone called the bone flap is removed using specialized tools. Temporarily, the bone flap is removed, then substituted after the brain surgery has been carried out. Below is the example of tumour removal through an eyebrow incision.

b) Neuroendos copies are the endoscopic approaches to brain surgery. Some brain tumors can now be removed through the nose without having to open the skull. This minimally invasive technique may seem simple, but endoscopic brain surgery is actually a complex procedure that was years in the making.

Technological advances for surgical visualization – our ability to see what’s going on in the brain and nasal cavities – have become much more advanced. And we now have sleek, slender tools to enter the nostrils, disturbing less surrounding healthy tissue.

Endoscopic techniques require fewer and smaller incisions, resulting in quicker recovery and less scarring than craniotomy. And by approaching pituitary adenomas, meningiomas, and chordomas from the bottom of the brain via the nasal cavity, we don’t have to move the brain nearly as much as we had to during craniotomy. This reduces the risk.

It can be used for the diagnosis and treatment the following problems:

Aqueduct stenosis causing Hydrocephalus, called as endoscopic third ventriculostomy (ETV)

2. Brain tumours: cysts, Intraventricular Brain tumours, Intraventricular Colloid cyst

3. Endonasal, transsphenoidal removal of pituitary tumour.

4. Endonasal removal of meningioma.
5. Craniopharyngioma

C) Stereotactic biopsies of the brain tumors
Stereotactic neurosurgery is brain mapping in a 3-D coordinate system. Neurosurgeons can accurately target any brain area in stereotactic space (3-Dimensional coordinate system) using CT scans, MRI, and 3-D computer workstations. A minimally invasive procedure using this technology to obtain brain tissue samples for the purpose of diagnosis is called stereotactic brain biopsy.

Benefits of Minimally Invasive Procedures

Less Pain

Less post-operative pain and discomfort is caused by MIS procedure. Research has shown less pain being reported by patients undergoing MIS procedures. Also, these patients require smaller pain relievers doses that patients undergoing traditional surgeries.

Shorter Hospital Stay

Hospital stay is shorter and patients can return to normal activities quicker. Patients undergoing MIS procedures are generally able to go home sooner.

Less Scarring

Smaller incisions are required in MIS procedures. Therefore the resulting scars would be smaller and less noticeable. The scars formed as a result of MIS have a less serrated appearance, thus looking pleasant.

Less Injury to Tissue

A majority of traditional surgeries require a long incision. Usually, this incision is needed to be made through muscle. A remarkable time is needed for the muscle to heal after surgery. There is less tissue damage and faster recovery due to the absence of long incisions in MIS and surgeons frequently don’t have to slit trough the muscles to complete the procedure.

Higher Accuracy Rate

A greater accuracy rate for majority of procedures. The surgeon has improved vision and magnification of internal organs as well as structures since MIS procedures make use of video-assisted equipment. Not every MIS procedures or surgeries may be suitable for each patient. Your personal options will be discussed by your surgeon before any surgery.

3. Image Guided Surgery

A. Intra-operative USG in Neurosurgery

In the past few years, there has been an increased demand for use of neuro-navigational systems in neurological operation theatres and have become one of the necessities for superior resection of neural lesions. Ultrasonography is a transducer device that uses reflective property for image buildup. Intra operative CT scan and MRI are very expensive.

The most useful one is with phase array transducer, that uses small acoustic lenses which are rectangular in shape with area of contact being 20 to 25 mm. Use of USG rose to its height in 1990s in other medical specialities but its use in Neurosurgery was in infancy period. But today it is taking pace and is commonly used for localisation of mass lesions.

Neuronavigation with the help of USG over the area of intent, the collection of 2D images can be used for forming 3D image volume, which takes around one minute of time.

B. Fluorescence guided resection (FGR): There is an increasing trend for use of 5 Aminolevulinic Acid (5-ALA) which helps to differentiate tumour borders and healthy brain tissue, which in turn help in the removal of tumours. This drug is taken oral before surgery and when exposed to blue light, it glows as hot pink in colour and tumours can be removed to a greater extent.

C. High rates of tumor excision can be achieved when this fluorescence technique when used in combination with intraoperative monitoring and mapping.

D. NeuroNavigation
Localization of brain lesions and prevention of damage to vital structures are important in operation of brain pathologies. Neuronavigation is the set of computer-assisted technologies used by neurosurgeons to guide or “navigate” within the confines of the skull or vertebral column during surgery to aid in accurate and safe excision of brain tumours.

Deep Brain Stimulation

Deep Brain stimulation (DBS) is an outcome of technical and scientific development in the field of Neuroscience and Functional neurosurgery. It is one of the effective surgical treatments for hypokinetic and hyperkinetic movement disorders which are refractory to medications. It has changed the modality of treatment for movement disorders like tremors, Parkinsons disease, dystonia and tend to be beneficial for neuropsychiatric illnesses like depression, epilepsy and obsessive-compulsive disorder

Awake Craniotomy Or “Awake” Brain Surgery

Awake brain surgery is primarily used for operations to treat epileptic seizures and Parkinson’s disease, but it is increasingly used for removal of brain tumors near portions of the brain that can affect critical functions. Remaining conscious allows you to answer questions that can help the surgeon identify areas of the brain affecting functions like vision, movement, or speech. The surgeon uses that information to precisely target the treatment.

In awake brain surgery, you still receive sedation and pain relief medication from your anesthesiologist. In addition, your surgeon may give you a local anesthetic to numb your scalp.You will not necessarily be fully aware or conscious during the entire procedure. The anesthesiologist can adjust levels of medication during surgery to wake you only at necessary times.

Trans-Sulcus Surgery For Brain Tumours

This is a minimally invasive approach, intended to preserve cortical brain functions. Conventional approaches to deep seated cerebral lesions are more invasive and associated with greater potential for irreparable injury to normal brain. It utilizes naturally existing corridors.

The trans-sulcal dissection is a safe, useful, and applicable approach. Through which it is possible to reach deeply seated lesions. It preserves the motor functions, provides wider exposure, minimizes the need of brain retraction during surgery, and preserves the gyral layers.

Stem cells in Neurosurgery

The adult human brain, in contrast to other organs such as skin and liver, lacked the capacity for self-repair and regeneration. Most likely restorative neurosurgery began three decades ahead in the western world in terms of research and clinical trials. It began with the vision of the possibility of replacing degenerating nerve cells. The final goal of this in neurosurgery is reconstructing neuronal pathways. This topic is being extensively researched.

Combining specialities with single aim of treating patients better. Team-working has been seen as an important essential in the delivery of modern medical care and quality. Neurosurgery is one of the branches in medicine, where teamwork finally decides the outcome for the patient.The multidisciplinary in-hospital teams include “staff” from different levels of the treatment pyramid (e.g. surgical technicians, nurses, anaesthesiologists, attending physicians, intensivists, neurologists, interventional neuroradiologists, physiotherapist and others). All of them need special training to handle neurosurgical patients, as these patients are unique and have unique problems. Favourable outcomes in patients afflicted with complex surgeries like skull base pathologies are not only due to meticulous surgical planning and execution or better infrastructure and they are also due to the collaborative efforts of numerous medical specialties and allied healthcare givers.

Common Problems ( arranged alphabetically)

1. Arterio Venous Malformation (AVM)

Arteriovenous malformations (AVMs) are faults in the blood vessels that are believed to be formed during fetal development i.e. before birth. In this condition the normal blood circulation in the body is disrupted due to the abnormal network between the arteries and veins, resulting in diversion of the blood from the capillaries that supply blood to the organs. An AVM can occur anywhere on the body; however those in the brain or spine especially can have widespread effects on the body.

Symptoms:

An AVM in the brain may not show any symptoms. It can cause

Over time brain AVMs can incur damage to the brain tissue due to inadequate blood supply, the effects of which slowly build up leading to symptoms in early adulthood.

Causes:

There is no particular cause of a brain AVM but research has revealed that most brain AVMs develop during fetal development. In a normal body, the heart supplies oxygen-rich blood to your brain through arteries. The blood flow in the arteries gets slowed down by passing through a series of smaller network of blood vessels and finally ending with the smallest blood vessels known as capillaries. The capillaries slowly provide oxygen rich blood to the brain tissue. After providing the tissue with the required nutrients and oxygen, the blood then passes into small blood vessels and then into larger veins thereby taking the blood back from the brain to the heart to get more oxygen.
In an AVM, the arteries and veins lack this supporting network of smaller blood vessels and capillaries. Instead, the blood flows quickly and directly from the arteries to veins, bypassing the surrounding tissues.

Diagnosis

A brain AVMs can be diagnosed with the following tests:

1. Computerized tomography (CT) scans

A CT scan is an imaging technique that is particularly useful as a quick initial diagnostic tool for brain hemorrhage.

2. Cerebral angiography (DSA)

Cerebral angiography is the most specific test that reveals the location and characteristics of the blood vessel pattern, which is important while planning treatment.

3. Magnetic resonance imaging (MRI)

MRI through the use of powerful magnets and radio waves creates images of your brain. A MRI is finer than a CT scan that can show more detailed changes in brain tissue associated with an AVM. It provides information regarding the exact location of the AVM and any associated bleeding in that area.

Treatment For AVM

The treatment of AVM depends on the symptoms, the type of AVM and its size and location.

1.Medical therapy:
Even if there are no symptoms, a person with an AVM should keep away from activities that will increase blood pressure and avoid blood thinners like warfarin. He should get regular checkups done with a neurologist or neurosurgeon.

2.Surgery
If an AVM has led to brain hemorrhage and/or is in an area of the brain that can be easily operated, then surgery may be recommended.

3.Endovascular embolization
In this procedure, the surgeon inserts a catheter (a long thin tube) into a leg artery and guides it through blood vessels to your brain using X-ray imaging or fluoroscopy. Here the arteries of the AVM can be blocked by using liquid tissue adhesives, micro coils, particles and other materials. A less invasive procedure than traditional surgery, endovascular embolization may be performed alone or is commonly used prior to other surgical treatments. This makes the procedure safer by decreasing the size of AVM or the chances of bleeding.

4.Stereotactic radiosurgery

If an AVM is located in an area that is difficult to operate by regular surgery, then it may be treated with stereotactic radiosurgery. Firstly, a cerebral angiogram is done to locate the AVM, and then focused high energy beam is concentrated on the brain AVM to cause direct damage to the vessels. This will produce a scar and allow the AVM to thrombose.

Large Cerebral Arterio Venous Malformation (AVM)

This 23 years old college going student presented with repeated episodes of convulsions. The MRI scan of the brain raised a suspicion of an AVM. There was no brain haemorrhage. The cerebral angiography showed a large AVM. This was embolised by my neuroradiologist colleague. The residual AVM was later excised completely by microsurgical techniques. The patient made uneventful recovery without any neurological recovery. However, his anticonvulsant medicines continued.

2. Brain Aneurysms

A weak or fine spot on a blood vessel in the brain that balloons out and fills with blood is called as a cerebral aneurysm.It can leak or rupture, spilling blood into the neighbouring tissue (commonly known as subarachnoid haemorrhage or SAH). Few cerebral aneurysms don’t bleed or cause other issues, especially those that are very tiny. These are incidentally detected in the course of investigation done for some other reason. Cerebral aneurysm can occur anywhere in the brain, but majority are located along a loop of arteries running between the underside of the brain and skull base (Circle of Willis).

Aneurysms may be a result of an abnormality in an artery wall that is congenital. Cerebral aneurysm is observed more commonly in people having particular genetic diseases, like connective tissue disorders and polycystic kidney disease, and specific circulatory disorders such as AVM i.e. arteriovenous malformations ( knotted tangles of veins and arteries in the brain that disrupt the flow of blood). Other causes can be trauma or head injury, high BP, infection, tumours, atherosclerosis and other diseases of the vascular system.

Types Of Aneurysms

Cerebral aneurysm is of 3 types.
1. Berry aneurysm, a rounded or pouch-like sac of blood attached by a neck or stem to an artery or a branch of a blood vessel is called a saccular aneurysm. It is the most commonly occurring form of cerebral aneurysm and is usually found on arteries at the base of the brain. It usually occurs in adults.
2.A lateral aneurysm is seen as a protuberance on one wall of the blood vessel,
3.Fusiform aneurysm is formed by the broadening along the blood vessel walls.

Size is also a used to classify aneurysms. Small aneurysms are not more than 10 mm in diameter (around the size of a large pencil eraser), larger aneurysm are around 11-25 mm (about a coin’s width), and giant aneurysms are greater than 25 mm in diameter.

RISK FACTORS
Brain aneurysms can happen to anyone and at any age. It is observed more commonly in adults than in children and its frequency is slightly more in women than in men. Higher risk is present in people with certain inherited disorders.

WHAT ARE THE DANGERS?
Haemorrhagic stroke, permanent brain damage and other serious complication or even death can be caused due to aneurysm that may burst and bleed into the brain. After bursting once, the aneurysm can even burst again. The re-rupture is typically devastating and can be life threatening.

INTRAVENTRICULAR BLEED
More grave post rupture complication of brain haemorrhage is vasospasm. In vasospasm, other blood vessels in the brain contract and restrict the flow of blood to essential areas of the brain. This decreased flow of blood can cause stroke or further tissue damage.

Hydrocephalus is another serious complication of subarachnoid haemorrhage. In this condition, excessive accretion of cerebrospinal fluid in the skull widens fluid pathways called ventricles that can bloat and exert pressure on the brain tissue.

Symptoms Of Cerebral Aneurysms

Symptoms are absent in most cerebral aneurysms until they either become large or burst. Aneurysms that are small and unchanging generally won’t produce symptoms. On the other hand a larger aneurysm growing steadily may exert pressure on tissues and nerves. The symptoms are pain above the eye as well as behind it, weakness, numbness, or paralysis on a single side of the face; dilation of pupils and changes in vision. When there is haemorrhage of an aneurysm, the person may experience an expected and extremely severe headache, vision problems, nausea, stiff neck and / or loss of consciousness. The headache is especially excruciating and is usually different in degree and intensity from other headaches. Sometimes an aneurysm leaks for days to weeks before it ruptures. During this period, “Sentinel” or warning headaches may be felt. Only a few people have sentinel headache before an aneurysm rupture.

Some other signs that a cerebral aneurysm has burst are nausea and vomiting along with severe headache, drooping eyelid, increased sensitivity to light, and confusion. Some people may experience seizures too. When people experience these symptoms or along with a combination of other symptoms, they should seek medical attention immediately.

Diagnosis Of Cerebral Aneurysms

Majority of cerebral aneurysms go undiscovered until they rupture or are detected by brain imaging which may have been suggested for some other condition. Many diagnostic methods are available to guide and give information about the aneurysm and the best method of treatment. The tests are generally done following a subarachnoid haemorrhage, for confirmation of the diagnosis of an aneurysm.Computed tomography (CT) of the head is a quick, pain free, non-invasive diagnostic tool that can reveal if a cerebral aneurysm is present and find out, for those aneurysms that have a burst, if there is blood leak into the brain.
Angiography is a dye test that is used to examine the arteries or veins. It is a significant diagnostic test in brain stroke management and accurately determines the shape size, location of the aneurysm, or the blood vessel that has bled.
MRI i.e. magnetic resonance imaging produces detailed images of the brain by using computer-generated radio waves and strong magnetic field. Images of blood vessel is produced using MRA (Magnetic resonance angiography). The images may be viewed as either 3 – dimensional pictures or 2 – dimensional cross slices of the brain and vessels. These pain free non-invasive procedures can help in understanding the size and shape of an aneurysm and to detect bleeding in the brain.

Treatment Of Cerebral Aneurysms

These are few surgical options available for the treatment of cerebral aneurysms –

i) Microvascular clipping is a procedure in which the blood flow to the aneurysm is cut. Once anaesthesia is administered, a portion of the skull is removed and the aneurysm is located. Using a microscope, the blood vessel that feeds the aneurysm is isolated and a small, metal, clothespin-like clip is placed on the aneurysm’s neck, cutting off its blood supply. The clip stays in the person preventing the risk of future bleeding. After replacing the piece of skull, the scalp is closed. It is found that clipping is highly effective, depending on the aneurysm’s location, shape and size.

ii)Endovascular embolization is a substitute for surgery. Once the patient is under anaesthesia, the physician inserts a catheter (long thin plastic tube) into an artery (generally in the groin) and threads it, using angiography, through the body to the aneurysm site. Detachable coils are passed through the catheter using a guide wire and released into the aneurysm. The aneurysm is filled with coils, blocking its blood circulation and causing blood to clot which in turn destroys the aneurysm.

iii) Other treatments for a cerebral aneurysms are to control the symptoms and can involve anticonvulsants for preventing seizures and analgesics for treating headaches. It is possible to treat vasospasm using calcium channel-blocking drugs. Also, if the person is restless, sedatives may be administered. A shunt can be inserted surgically into a ventricle many months after the rupture if the cerebrospinal fluid buildup is causing harmful pressure on surrounding tissue. People who have experienced a subarachnoid hemorrhage usually require speech, rehabilitative and occupational therapy to regain lost ability and learn to cope with any disability that is permanent.

This 54-year-old gentleman presented with a brain hemorrhage. The cerebral angiography showed a large aneurysm of the middle cerebral artery. The aneurysm was clipped successfully. He made an uneventful recovery. We occasionally use endoscopes during these surgical procedures to confirm complete occlusion of the aneurysm and to exclude occlusion of any other blood vessel.

DURING SURGERY

After Clipping The Aneurysm

Intracerebral Hemorrhage (ICH): uncontrolled hypertension

ICH: PROGRESSION OF INNOCUOUS LOOKING BLEED

Small innocuous-looking intracerebral hemorrhage can progress over time and may need surgery.

Uncontrolled Hypertension

Hypertensive Intracranial Haemorrhage ( Brain Haemorrhage) is a type of stroke, which is caused by the brain’s artery bursts and the blood spreads nearby areas, and bleeding starts from surrounding tissues. This bleeding permanently damages brain cells. In fact, hypertension is the most common cause of intracerebral hemorrhages.

Long-standing poorly controlled hypertension leads to a variety of pathological changes in the vessels. It can cause

1.microaneurysms of perforating arteries (Charcot-Bouchard aneurysms). They are usually

– small (0.3-0.9 mm) diameter

– occur on small (0.1-0.3 mm) diameter arteries

– distribution which matches the incidence of hypertensive haemorrhages (80% lenticulostriate, 10% pons, 10% cerebellum)

– found in hypertensive patients

– may thrombose, leak (see cerebral microhemorrhages) or rupture

2.accelerated atherosclerosis: affects larger vessels

3.hyaline arteriosclerosis, which is then generalised and can affect any artery in the body

Brain haemorrhage following untreated hypertension is worst, as it can cause rehaemorrhage even after surgery

Not all hypertensive hemorrhage need surgery as shown below.

STROKE – What is it?
An attack on the brain is called Stroke. Anyone of any age can suffer from it. It takes place when blood flow to a part of the brain is stopped. During its occurrence, cells of the brain are deprived of oxygen and glucose and begin to perish. During stroke when brain cells perish, abilities like muscle control and memory controlled by that region of the brain are lost.
Blood flow may be compromised due to various mechanisms:

Causes of stroke – What are the reasons?

• Blockage of an artery
Stroke is most frequently caused by the clogging of an artery in the brain due to a clot (thrombosis). The risk factors include: high BP (hypertension), high cholesterol, diabetes and smoking.

• Embolic stroke
Another kind of stroke can take place when a blood clot or a par of atherosclerotic plaque (deposits of cholesterol and calcium on the wall of the inside of the heart or artery) breaks loose, travelling through arteries that are open, and gets stuck in an artery of the brain. When this takes place, the flow of oxygen-rich blood to the brain is obstructed and a stroke takes place. This kind of stroke is called an embolic stroke.

• Cerebral haemorrhage
A cerebral haemorrhage takes place when there is a rupture in the brain’s blood vessel thus causing bleeding into the surrounding brain tissue. Stroke can be caused by a cerebral haemorrhage (bleeding in the brain).The most frequent cause of bleeding within the brain is high blood pressure that is not controlled.

• Subarachnoid haemorrhage
In a subarachnoid haemorrhage, blood gathers in the gap beneath the arachnoid membrane lining the brain. The blood comes from an anomalous blood vessel that leaks or ruptures. Usually this is from an aneurysm.

• Vasculitis
Vasculitis is a rare cause of stroke. In vasculitis, blood vessels become inflamed.

• Migraine headache
Individuals having migraine headache show a minor increase in the occurrence of stroke.

What are the risk factors for stroke?

Overall, the most frequently observed risk factors for stroke are:
– High BP
– High cholesterol
– Smoking
– Diabetes
– Increasing age Sedentary lifestyle: lack of exercise Certain blood disorders

What Is A Transient Ischemic Attack (TIA)- Mini Stroke?

A transient ischemic attack (TIA) is an episode that is short-lived (not more than 24 hours) of brief impairment to the brain which occurs due to loss of blood supply. The region of the body controlled by the part of the brain affected by TIA loses its functions. The loss of blood supply to the brain is most commonly caused by a clot that unexpectedly forms in a blood vessel inside the brain (thrombosis). However, it can also be caused from a clot that forms somewhere else in the body, dislodges from that place, and moves in gets stuck in the brain’s artery (emboli). Other causes of a TIA are spasm and a bleed. TIA is referred to as a “mini-stroke by many people. Few TIAs develop gradually, while others develop quickly. All TIAs resolve within a period of 24 hours. In comparison to TIAs, strokes take longer time to resolve, and with strokes, there are possibilities of complete function never being regained and reflect a more lasting and grave problem. Even though most TIAs often last only for few minutes, all TIAs should be treated with the same medical attention as a stroke in order to prevent recurrences and/or strokes. TIAs can take place once, several times, or precede a permanent stroke.

All patients with TIA need investigations and treatment before it proceeds to a full blown stroke. Few patients may need surgery to prevent recurrence of TIA.

What is the impact of strokes?
Stroke is the 3rd largest cause of death (behind heart disease and all types of cancer) in the US. The major impact of a stroke is the loss of independence that takes place in 30 percent of the people who survive it.

What are the symptoms of stroke?
Deprived of oxygen, the brain cells stop performing their usual tasks. The symptoms of stroke depend on the region of the brain affected by it and the extent to which the brain tissue is damage. No symptoms may be caused by minor strokes, but may still cause damage to brain tissue. Such strokes which don’t cause symptoms are called silent strokes.

Warning Signs of Stroke

Sudden numbness or weakness in the face, arm or leg (especially on one side of the body).
Sudden confusion or trouble speaking or understanding speech.
Sudden vision problems in one or both eyes.
Sudden difficulty walking or dizziness, loss of balance or problems with coordination.
• Unexpected, intense headache with no known cause

What should you do if you suspect you or someone else is having a stroke?
If any of the above mentioned symptoms suddenly appear, get immediate medical attention. Hence, the first thing you should do is call the emergency medical helpline number. Also, contact the family doctor and/or neurologist. The first priority however is making sure that the ambulance arrives without any delay

The affected individual should lie flat to allow a proper blood flow to the brain.
If there is drowsiness, unresponsiveness, or nausea, the individual should be placed in the rescue position on their side in order to prevent choking if vomiting takes place.
Although aspirin plays a huge role in prevention of stroke, once the stroke’s symptoms commence, it is normally recommended that further aspirin not be consumed until the patient gets medical attention. If stroke is of the bleeding kind, aspirin could even worsen the situation.

How is a stroke diagnosed?
A stroke is a situation of a medical emergency. Any person suspected of having a stroke must receive medical attention immediately. First, the doctor takes a medical history from the patient and carries out a physical examination. If an individual has been receiving treatment from a particular doctor, it would be ideal for that doctor to take part in the assessment. The evaluation’s accuracy can be improved by the patient’s previous knowledge. Just because a person has a speech that is slurred or experiences weakness on a single side of the body doesn’t have to signal the occurrence of a stroke. There may be many other reasons causing these symptoms.

Other conditions that can mimic a stroke include:

Brain tumors
A brain abscess (a formation of pus in the brain caused due to bacteria or a fungus)
Migraine headache
Bleeding in the brain either spontaneously or from trauma
Meningitis or encephalitis
An overdose of specific medications, or
An imbalance of sodium, calcium, or glucose in the body may also cause alterations in the nervous system that can mimic symptoms of a stroke.

Computerized tomography:
A special x-ray test known as a CT scan of the brain is often carried out to help determine the cause of a suspected stroke. A CT scan is used to probe for bleeding or masses inside the brain, a much different situation compared to a stroke which is also treated differently.

INFARCT in the brain

Difference between ischemic infarct ( no blood flow) and hemorrhagic infarct (excessive blood or clot or hemorrhage)

Golden Period

A door-to-treatment time of 60 minutes or less is the goal in the treatment of brain stroke. This 60-minute period is often referred to as the “golden hour” of acute ischemic stroke treatment during which a focused diagnostic workup must be completed to rule out conditions that may mimic stroke as well as to proper treatment.

If thrombolytic therapy is not started in the window period, initial ischemia (a state of low blood flow) might progress to a full-blown established infarct, as shown in the figure below.

MRI scan

Magnetic resonance imaging (MRI) makes use of magnetic waves instead of x-rays to image the brain. Compared to images from CT, the MRI images are more detailed, but this isn’t a first line test in stroke.

Computerized tomography with angiography:
By making use of dye which is injected into a vein in the arm, images of the brain’s blood vessels can give info regarding aneurysms or arteriovenous malformations.

Conventional angiogram:
An angiogram is a test that is at times used for viewing the blood vessels. A long catheter tube is inserted into an artery (generally in the groin region) and dye is injected while x-rays are taken simultaneously. Though an angiogram provides few of the most detailed images of the blood vessel anatomy, it is at the same time an invasive procedure and it is made use of only when absolutely required.

Carotid Doppler ultrasound:
A carotid Doppler ultrasound is a non-invasive (without injections or placing tubes) technique making use of sound waves to screen for narrowings and reduced blood flow in the carotid artery (the main artery in the neck supplying blood to the brain).

Heart tests:
Specific tests to evaluate function of heart are frequently carried out in stroke patients to probe an embolism’s source.

Blood tests:
Blood tests like sedimentation rate and C-reactive protein are performed to check for signs of inflammation that may suggest inflamed arteries. Specific blood proteins which can increase the possibility of stroke by thickening the blood are measured.

What is the treatment of a stroke?

Tissue plasminogen activator (TPA) :
Alteplase (TPA) can be used as a clot-buster drug for dissolving the blood clot that is causing the stroke. The window of opportunity to use this drug is narrow, about 4-8 hours. The earlier that it is administered, the better the result and the lesser the potential for the complication of bleeding into the brain.

Heparin and aspirin :
Sometimes, blood-thinning drugs (anticoagulation; for example, heparin) are also used for treating stroke patients in the hopes of boosting the patient’s recovery.

Managing other Medical Problems :
Controlling BP (blood pressure) and cholesterol are vital to prevent of future stroke occurrence. In patients having diabetes, the sugar (glucose) level in the blood is frequently elevated after a stroke. By controlling the glucose level in these patients, the size of a stroke can be minimized.

Rehabilitation :
When a patient no longer is seriously ill following a stroke, the healthcare staff focuses on boosting the functional abilities of the patient. The rehabilitation process may include a few or all of the following:
• Speech therapy for relearning talking and swallowing;
• Occupational therapy for regaining functions in the arms and hands;
• Physical therapy for improving strength and walking; &
• Education of the family to orient them in caring for their loved one at home and the challenges they would face.

The motive is that the patient must be able to resume as many, if not every, of their pre-stroke functions & activities.

What complications can occur following a stroke?

In spite of early arrival at the hospital and appropriate medical treatment, a stroke can worsen. It isn’t surprising for a stroke and a heart attack to take place at the same time or in very near proximity to each other. Swallowing may be affected during the severe illness. The weakness affecting the arm, leg, & side of the face may also impact the swallowing muscles.

Multidisciplinary Approach Prevention:
The chances of suffering a stroke can be remarkably reduced by controlling the risk factors.
– Controlling Blood Pressure
– Reduce Smoking
– Control Diabetes
– Blood thinner/warfarin
– Aspirin and other antiplatelet therapy

Regular exercise

Carotid endarterectomy:
In several cases, an individual can suffer a TIA or a stroke which is caused due to narrowing or ulceration (sores) of the carotid arteries (the chief arteries in the neck supplying the brain). Carotid endarterectomy is an operation that cleans out the carotid artery restoring normal blood flow. The occurrences of a subsequent stroke are remarkably decreased by this procedure.

ProphylacticSurgery In Tia

CAROTID ARTERY DISEASE CASE HISTORY

This 46-year-old patient presented with repeated episodes of giddiness and transient limb weakness (called transient Ischemic attacks). He was a hypertensive, diabetic, and heavy smoker. The carotid angiography showed severe stenosis of the internal carotid artery at its origin causing compromise of brain circulation. The patient preferred carotid stenting over open surgery.

Following successful carotid stenting by our interventional neuroradiologist, patiently made an uneventful recovery. His symptoms disappeared completely. In addition, he needed a complete change in his lifestyle.

Carotid Endarterectomy Example

This 30-year-old patient presented with transient limb weakness. He had suffered from a similar episode 3 years ago, from which he had improved significantly. He was non-diabetic but was hypertensive and a heavy smoker. MRI with MR angiography, cerebral angiography, and carotid showed a large floating thrombus in the internal carotid artery at its origin.

SURGERY: He underwent an emergency open carotid endarterectomy with excellent postoperative recovery. His limb weakness has not recurred or deteriorated since then.

Revascularisation Procedures For TIA

Encephaloduroarteriosynangiosis (EDAS), which involves the transposition of a segment of a scalp artery onto the surface of the brain, is a surgical treatment aimed at improving collateral blood flow.

Generally, it is advocated in children with Moya Moya disease, but has shown promising early results in the treatment of adult patients with moyamoya disease (MMD) and more recently in patients with intracranial atherosclerotic steno-occlusive disease. The rates of stroke after EDAS are lower than those reported with other treatments, including intensive medical therapy in patients with TIA.

CT and MRI are the recommended modality to diagnose TIA and image ischemic lesions. In addition, Transcranial Doppler sonography (TCD) and Digital Subtraction Angiography (DSA) are two acceptable alternatives for diagnosing TIA patients.

PET imaging can be used to quantify areas of altered cerebral blood flow and abnormal glucose and oxygen metabolism. This can be used to elucidate areas of ischemic penumbra and infarcted tissue. It is used as an imaging biomarker to detect high-risk carotid plaques

STA-MCA Anastomosis Surgery

Direct revascularization (STA-MCA bypass) involves use of a branch of a scalp artery (STA) for direct anastomosis (connection) to a branch of the brain artery (MCA) on the outer surface of the brain. This procedure benefits patients by providing an immediate improvement in blood supply to the brain.

This can be done as a stand alone procedure or can be combined with EDAS procedure.

What is in the future for stroke treatment?

At present, studies are being performed on other drugs which dissolve clots. These drugs are given either in the veins (like TPA) or into the clogged artery directly. These studies are done for determining which stroke patients may benefit from this aggressive treatment form. New medications are also being tested which help to slow the nerve cells’ degeneration which are oxygen deprived during a stroke. These drugs are known as “neuroprotective” agents, for example: sipatrigine. Chlormethiazole is another example. Chlormethiazole works by modifying the genes expression inside the brain. (Genes generate proteins determining a person’s makeup.) Lastly, stem cells having the potential to develop into various different organs, are being used for trying to replace brain cells that are damaged by an earlier stroke. In several academic medical centres, few of these experimental agents may be offered in the setting of a clinical trial. Although new therapies for the treatment of patients following a stroke are on the verge, they aren’t yet perfect and complete function may not be restored to a stroke victim.

Brain Tumors

A brain tumor is a growth of abnormal cells that have formed in the brain. Some brain tumors are malignant (cancerous), while others are not (non-malignant, non-cancerous or benign). A brain tumor can form in the brain or other parts of the central nervous system (CNS), such as the spine or cranial nerves. The brain plays a central role in the control of most bodily functions, including awareness, movements, sensations, thoughts, speech, and memory. A tumor can affect the brain’s ability to work properly and adequately perform such functions.

What is the difference between malignant and non-malignant brain tumors?

Whether a tumor is malignant or not depends on how quickly the cells reproduce. If the tumor is made up of cells that multiply slowly, then it is usually non-malignant; however, if the cells multiply and spread quickly, then the tumor is malignant.

Non-malignant (benign) brain tumors are not cancerous. These types of tumors grow relatively slowly and do not tend to spread. Even though they are not cancerous, these tumors can still cause symptoms due to pressure on the brain and may need treatment. A non-malignant brain tumor can still be a serious medical condition.

Malignant brain tumors are cancerous. These types of tumors generally grow faster, and are more aggressive than non-malignant tumors. They often spread and damage other areas of the brain and spinal cord. Malignant brain tumors need to be treated as soon as possible to prolong life.

Glioblastoma is a type of very aggressive brain tumor. It is also known as glioblastoma multiforme. About 12 to 15 percent of people with brain tumors have glioblastomas.

This type of tumor grows very fast inside the brain. Its cells copy themselves quickly, and it has a lot of blood vessels to feed it. However, it rarely spreads to other parts of the body.

Brain tumors may also be classified as either primary or secondary/metastatic. Primary tumors originate in the brain, and the most common types are meningiomas and gliomas. Metastatic, or secondary brain tumors arise from outside the brain in another organ such as the breast or lung and spread to the brain. These are the most common brain tumors.

Various types of primary brain tumours exist getting their names from the type of cells involved.

Examples include:
1) Gliomas: These tumours commence in the brain or spinal cord. It includes astrocytomas, ependymoma, glioblastomas, oligoastrocytomas and oligodendrogliomas.
2) Meningiomas: A tumour arising from the membranes surrounding your brain and spinal cord (meninges) is called Meningioma.
3) Acoustic neuromas (schwannomas): Benign tumours developing on the nerves that regulate balance and hearing starting from your inner ear to your brain.
4) Pituitary adenomas: Mostly these are benign tumours which develop in the pituitary gland at the brain’s base. These tumours may affect the pituitary hormones with effects observed throughout the body.
5) Medullolastmas: Medulloblastomas are the most frequent cancerous brain tumours observed in children. It begins in the lower back portion of the brain and is likely to spread through the spinal fluid.Although these tumours occur in adults, they are less common.
6) PNETs: Primary neuroectodermal tumours (PNETs) are rare cancerous tumours starting in the brain’s embryonic (foetal) cells. They can take place anywhere in the brain.
7) Germ cell tumours: Germ cell tumours can begin during childhood where there will be formation of testicles or ovaries. But occasionally germ cell tumours progress to other body parts such as brain.
8) Craniopharyngiomas: It is a rare, non-cancerous tumour beginning near the pituitary gland (gland secreting hormones that controls many functions of the body) of the brain. The pituitary gland and other structures near the brain are affected as the Craniopharyngiomas gradually grows.

Secondary (metastatic) brain tumours.

Cancer that originates at other parts and spreads to the brain.
In rare cases, a metastatic brain tumour can be the initial sign of cancer that began somewhere else in your body. Secondary brain tumours are more frequent than primary tumours.

Any type of cancer can metastasize to the brain, but the most frequent types include:
1) Breast cancer
2) Colon cancer
3) Kidney cancer
4) Lung cancer
5) Melanoma

What is tumor grading?

Tumor grade has long been a way to define the aggressiveness of a tumor, particularly for malignant brain tumors such as glioma but also for non-malignant (benign) brain tumors including meningioma.

Traditionally, tumors have been classified as grade 1 to 4 based on histology (cells as viewed under a microscope) and molecular markers. Grade 1 tumors occur primarily in children and represent a type separate from grade 2-4 (seen primarily in adults). Grade 2 tumors are considered low grade, but some can be aggressive. Grade 3 and 4 tumors are defined as high grade.

What are molecular markers?

Not all brain tumors are the same. Some tumors have differences in the genetic or molecular makeup of the cells. These differences are called molecular markers, or biomarkers. Molecular markers are becoming increasingly important for brain tumor diagnosis and treatment. For example, some molecular markers help determine how aggressive a tumor may be. Others determine how responsive a tumor will be to treatment.

Some common molecular markers include the following:

IDH1 and IDH2
MGMT
1p/19q co-deletion
BRAF
EGFR
TP53
ATRX
TERT
PTEN
NTRK
FGFR
Risk Factors for Brain Tumours

1.Genetic and hereditary risk factors

Inherited traits are carried in genes. Each individual has two copies of each gene, one from each parent. Genes often contain small changes. Sometimes these changes do not cause any problems, but sometimes these changes are more serious and can interfere with the way the gene is supposed to work.

There are a few rare, inherited genetic syndromes that are associated with brain tumors., including Neurofibromatosis 1 (NF1 gene), Neurofibromatosis 2 (NF2 gene), Turcot syndrome (APC gene), Gorlin syndrome (PTCH gene), Tuberous Sclerosis (TSC1 and TSC2 genes) and Li-Fraumeni syndrome (TP53 gene).

Although 5-10% of persons with brain tumors have a family history of a brain tumor, the vast majority of CNS tumors appear not to be a part of inherited genetic syndromes.

If multiple members of your family have been diagnosed with brain tumors, or you have concerns about starting a family, a genetic counselor may be able to help.

2.Environmental risk factors

Other than family history, the most consistently identified risk factor associated with brain tumor development is therapeutic or high-dose ionizing radiation.With regard to medical diagnostic radiation exposure, small increases in brain tumor risks have been reported. Although certain brain scans and radiation therapy used to treat brain tumors use ionizing radiation, the risk of developing a new brain tumor due to these causes is very low.

With respect to the impact of nonionizing radiation from cell phones, the association between this exposure and brain cancer has been the subject of much research.

Industrial chemicals have long been suspected as a cause of glioma due to their ability to cross the blood–brain barrier.The blood-brain barrier protects the brain from toxins and pathogens. Despite numerous chemical, environmental, and occupational exposures having been explored in epidemiological studies of glioma, results have been inconsistent for most factors.

Symptoms

Glioblastoma causes symptoms when it presses on parts of your brain. If the tumor isn’t very large, you might not have any symptoms. Which symptoms you have depends on where in your brain the tumor is located.

Symptoms can include:

Diagnosis:

If symptoms suggesting brain tumour is detected by your doctor, he will give you a physical exam and inquire about your personal and family health history. You may have to undergo one or more of the following tests:

Neurologic exam

Your vision, hearing, alertness, muscle strength, coordination and reflexes are checked by your doctor. He also examines your to check for swelling caused by a tumour exerting pressure on the nerve connecting the eye & the brain.

MRI

Detailed pictures of areas inside your head is made using a big machine with a powerful magnet linked to a computer. At times a special dye (contrast material) is injected into your hand or arm’s
blood vessel to distinguish the tissues of the brain. Abnormal areas like tumour can be shown by these pictures.

CT scan

A computer linked x-ray machine takes a series of detailed pictures of your head. A contrast material may be injected into a blood vessel in your arm or hand. It is easier to see abnormal areas because of the contrast material.

Angiogram

By injecting dye into the bloodstream, blood vessels in the brain show up on an x-ray. If there is presence of a tumour, the x-ray may show the tumour or blood vessels feeding into the
tumour.

Spinal tap

A sample of cerebrospinal fluid may be removed by your doctor. Local anaesthesia is used in this procedure. The doctor makes use of a long, fine needle to remove fluid from the spinal column’s lower part. A spinal tap takes about half an hour. To prevent getting a headache you must lie flat for several hours following the procedure. The fluid is checked by a laboratory for cancer cells or other signs of problem.

Biopsy

Removing of tissue to check for tumour cells is called biopsy. A pathologist examines cells under a microscope to look for abnormal cells. A biopsy can detect cancer, alteration in tissue that may lead to cancer and other conditions. A biopsy is the only definite means of diagnosing a brain tumour, find out what grade it is, and plan treatment.

The surgeon can acquire tissue to check for tumour cells in 2 ways:

Excision biopsy (open surgery): The tissue sample is taken when you have surgery to remove a portion of the entire tumour.

Stereotactic biopsy: A local or general anaesthesia may be administered to you and you’ll be made to wear a rigid head frame for this procedure. The surgeon creates a small incision in the scalp and after drilling a tiny hole (a burr hole) into the skull through which CT or MRI is guided to the tumour’s location. A sample of tissue is withdrawn with the needle. In case the tumour is deep inside the brain or in a region of the brain that cannot be operated on, a needle biopsy may be used.

But, if the tumour exists in the brain stem or certain other regions, the surgeon may not be able to acquire tissue from the tumour without harming normal tissue of the brain. In such cases, MRI, CT or other imaging tests are used by doctors to acquire as much information as possible about a brain tumour.

Treatment:

Individuals suffering from brain tumour have a vast number of treatment options like surgery, radiation therapy, and chemotherapy. A lot of people receive a combination of treatments. The treatment choice mainly depends on the following:

Type of brain tumour and its grade.
Tumour’s location in the brain
Size of tumour
Your age and general health

i) Surgery
The usual first treatment for a majority of brain tumours is surgery. Prior to the commencement of surgery, general anaesthesia may be administered to you, and your scalp is shaved. You won’t probably need your head shaved entirely.

Craniotomy is a surgery to open the skull. An incision is made in your scalp and a special type of saw is used to remove a section of bone from the skull. You may be conscious when a part or all of the brain tumour is removed by the surgeon. The tumour is removed as much as possible. You may be asked to move a leg, count numbers, say the alphabet or recite a story. Your ability to follow these instructions helps the surgeon to protect the brain’s important parts. After the removal of the tumour, the opening of the skull is covered with a piece of bone or with a metal or fabric piece. The incision in the scalp is then closed by the surgeon. Sometimes, it isn’t possible to perform a surgery. But in case the tumour is in the brain stem or certain other areas, it is very complicated to remove the tumour without causing harm to normal brain tissue. Individuals who cannot have surgery may be given radiation therapy or other treatment.

ii) Radiation Therapy
Using high-energy x-rays, gamma rays, or protons brain tumour cells are killed by radiation therapy.
Following surgery comes radiation therapy. The tumour cells that may remain in the area is killed by the radiation. Sometimes, who can’t have surgery performed on them receive therapy instead.

It is used mainly for malignant tumours, but can also be used in a few non-malignant tumours (to control growth) particularly if they are small or located in critical locations of the brain.

Internal and external types of radiation therapy are used by doctors for treating brain tumours:
External radiation therapy: You’ll receive treatment in a hospital or clinic. A big machine outside the body aims radiation beams at the head. The radiation may be aimed at the tumour and brain tissue nearby or the entire brain since cancer cells may invade normal tissue around a tumour. Some people require radiation aimed at the spinal cord too.

The patient’s age, the type and the size of the tumour determines the treatment protocol. The most common radiation treatment for brain tumour is fractionated external beam therapy. Here the total dose of radiation is given to the patient over several weeks helping to protect the healthy tissue in the area of the tumour. The treatments generally last 5 days a week for several weeks, where each sitting takes around 1 hour.

Other ways of delivering external beam radiation are being studied by some treatment centres:
Intensity-modulated radiation therapy or 3dimensional conformal radiation therapy: computers are used by these type of treatment to target the brain tumour more closely in order to reduce thedamage to healthy tissue.

Proton beam radiation therapy: Instead of x-rays, the source of radiation here is protons. The proton beam is aimed at the tumour. Compared to the dose of radiation from an x-ray beam, the dose from a proton beam is less.

Stereotactic radiation therapy: Narrow beams of x-rays or gamma rays are directed at the tumor from different angles. For this procedure, you wear a rigid head frame. The therapy may be given during a single visit (stereotactic radiosurgery) or over several visits.

Internal radiation therapy (Implant radiation therapy or brachytherapy): Internal radiation is generally not used for brain tumours treatment and is under study. The radiation comes from radioactivematerial generally contained in very tiny implants known as seeds. The seeds are positioned in the inside of the brain and give off radiation for months. There is no need to remove them once the radiationis gone.

iii) Chemotherapy
Chemotherapy means making use of drugs for killing cancer cells. Many times, Chemotherapy is used for treating brain tumors. Drugs can be administered in the following ways:

By mouth or vein (intravenous): Chemotherapy can be administered during and after radiation therapy. After entering the bloodstream, the drugs travel throughout the body. They may be administeredin the hospital’s outpatient part, at the doctor’s office, or at home. Seldom, you may require to stay in the hospital.
Chemotherapy’s side effects depend chiefly on drugs which are given and the quantity of it. Common observed side effects are nausea and vomiting, appetite loss, headache, chills and fever, and weakness.
If the levels of healthy blood cells are reduced by the drugs, you’re more prone to get infections, bruise or bleed easily, and experience tiredness and weakness. Your health care team would inspect for lowevels of blood cells. Few of the side effects can be relieved with the help of medicine.

Commonly used chemotherapy is temozolomide (Temodar), bevacizumab, polifeprosan 20 with carmustine implant, lomustine .

Targeted chemotherapy

Chemotherapy and targeted therapy are both treatments that attack cancer cells. Targeted therapy is less toxic to healthy cells than chemo. Both options are often done in conjunction with other treatments, such as radiation.

Targeted cancer therapies are drugs or other substances that block the growth and spread of cancer by interfering with specific molecules (“molecular targets”) that are involved in the growth, progression, and spread of cancer. Targeted cancer therapies are sometimes called “molecularly targeted drugs,” “molecularly targeted therapies,” “precision medicines,” or similar names.

Targeted therapies differ from standard chemotherapy in several ways:

Targeted therapies act on specific molecular targets that are associated with cancer, whereas most standard chemotherapies act on all rapidly dividing normal and cancerous cells.

Targeted therapies are deliberately chosen or designed to interact with their target, whereas many standard chemotherapies were identified because they kill cells.

Targeted therapies are often cytostatic (that is, they block tumor cell proliferation), whereas standard chemotherapy agents are cytotoxic (that is, they kill tumor cells).

iv) Nutrition
You need to eat well in order to take good care of yourself. You require the correct amount of calories for maintaining a good weight. Also, you require sufficient protein to sustain your strength. Eating properly can go a long way in helping you feel better and have extra energy.

v) Supportive Care
Seizures (convulsions) cab be caused by brain tumours. Specific drugs can help in preventing or controlling seizures. You will receive supportive care before, during, and post-cancer treatment. It will help in improving your comfort and quality of life during treatment.

vi) Rehabilitation
Rehabilitation is a very significant part of the treatment plan. Rehabilitation goals depend on your needs and the extent to which the tumour has affected your ability to perform daily activities.
Few individuals may never regain all the abilities possessed by them before the brain tumour and its treatment. But every effort is made by your healthcare team to help you get back to regular activities without delay.
Children suffering from brain tumours may have special requirements. Many times in the hospital or at home, children have tutors.

Several types of therapists can help:

Physical therapists: Paralysis may be caused by brain tumours and their treatment. Weakness and problems with balance may also be caused by them. Physical therapists assist people in regaining strength and balance.
Speech therapists: Individuals having trouble speaking, expressing thoughts, or swallowing are helped by speech therapists.
Occupational therapists: Occupational therapists assist people in learning to accomplish activities of daily living, like eating, using the washroom, having baths, and dressing.
Physical medicine specialists: Medical doctors with special training assist individuals with brain tumours to stay very active. They can assist individuals to regain lost abilities and getting back to daily activities.

New treatments for glioblastoma are being tested in clinical trials. These treatments include:
immunotherapy — using your body’s immune system to kill cancer cells
gene therapy — fixing defective genes to treat cancer
stem cell therapy — using early cells called stem cells to treat cancer
vaccine therapy — strengthening your body’s immune system to fight off cancer
personalized medicine — also called targeted therapy
If these and other treatments are approved, they could one day improve the outlook for people with glioblastoma.

Survival rates and life expectancy
The median survival time with glioblastoma is about 12 months who get surgery, chemotherapy, and radiation treatment.

Extending life expectancy
New treatments are extending life expectancy even more. People whose tumors have a favorable genetic marker called MGMT methylation have better survival rates.

MGMT is a gene that repairs damaged cells. When chemotherapy kills glioblastoma cells, MGMT fixes them. MGMT methylation prevents this repair and ensures that more tumor cells are killed.