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