PREVENTING STROKE A COMPREHENSIVE APPROACH

Did you know?

• Brain Stroke (Brain attack) is the leading cause of disability and fourth common cause of death.

• Timely intervention can save brain damage. It is estimated that one million brain cells will die every minute after the onset of stroke.

• Majority of the strokes are preventable.

• Prevention needs to be done in two phases. Primary prevention wherein occurrence of stroke itself is prevented. Secondary prevention is to prevent the recurrence of a stroke.

Understanding Stroke

Stroke is a leading cause of disability worldwide and ranks as the fourth most common cause of death. Swift medical intervention is crucial in minimizing brain damage, as an estimated one million brain cells die every minute following the onset of a stroke. Fortunately, the majority of strokes are preventable through timely action and appropriate measures.

Defining a stroke

Stroke is a sudden and catastrophic event that results in the loss of vision, memory, sensation, speech, or motor function due to an interruption of blood flow to the brain.

Strokes can occur at any age, and the specific type and affected brain regions often vary based on the individual's age and underlying health conditions. In younger individuals (under 40), a stroke is often linked to an underlying disease, necessitating thorough evaluation and treatment.

Types of Brain Strokes

Similar to a heart attack, a stroke is a vascular condition affecting the blood vessels of the brain. The term "brain attack" is used to emphasize the need for urgent and timely treatment. Brain strokes can be classified into four main types

Ischemic Stroke

This type accounts for about 60 per cent of all strokes and occurs when a blood vessel supplying the brain is blocked, leading to reduced blood flow. It commonly presents as sudden weakness or paralysis, usually without loss of consciousness. A CT scan will show a darkened area in the affected part of the brain.

Hemorrhagic Stroke

In this type, a blood vessel ruptures, causing bleeding within the brain tissue, accounting for about 20 per cent of strokes. This is often referred to as a brain hemorrhage. Symptoms include a sudden, severe headache, possibly with loss of consciousness and seizures. High blood pressure is commonly observed, and a CT scan will reveal a bright white area indicating the bleed.

Subarachnoid   Hemorrhage

This occurs when there is bleeding around the brain within the protective membranes. It is characterized by a sudden, intense headache, often described as the worst headache one has ever experienced. Other symptoms include vomiting, loss of consciousness, and neck pain. This type is typically caused by an aneurysm, an abnormal enlargement of a blood vessel in the brain.

Cortical Venous Thrombosis

Known as venous stroke, this type results from the blockage of cerebral veins responsible for draining blood from the brain. Causes include dehydration (due to excessive sweating, diarrhoea), anemia, infections, hormonal therapies, and, in women, inadequate fluid intake postpartum. It is more common in rural areas where women may be traditionally discouraged from drinking sufficient water after childbirth.

Primary Prevention Strategies

Stroke is fundamentally a vascular disease of the brain. Therefore, individuals over the age of 40 should undergo regular screenings for stroke risk factors. In high- risk groups, such as those with a family history of stroke, screening should begin at age 25. Key risk factors include

• Diabetese

• Hypertension

• Obesity

• Smoking

• Excessive

• alcohol consumption

• Drug

• abuse

• Familial dyslipidemias

• Hyperhomocysteinemia

• Certain infections and genetic syndromes

People with these risk factors require comprehensive medical screening, including genetic, molecular, biochemical, and vascular assessments, to detect potential problems early and take preventive measures.

Recognising warning signs

Transient Ischemic Attacks (TIAs) are brief episodes that often precede a major stroke. Symptoms include sudden loss of vision, sensation, speech, or memory, as well as weakness or imbalance that lasts for a few seconds and then resolves completely.

Other symptoms may include severe dizziness, vomiting, focal seizures, and sudden confusion. These signs should not be ignored and require immediate investigation.

Snoring, particularly associated with sleep apnea syndrome, also increases the risk of stroke and heart attacks. MRI scans and carotid Doppler studies can help identify individuals at risk of stroke, allowing for timely intervention.

Secondary prevention

After a stroke, the risk of recurrence is significant. Continuous monitoring and management are essential to prevent a second stroke. This includes maintaining a healthy diet, regular exercise, proper sleep, avoiding smoking and excessive alcohol, and managing other risk factors. Regular health checks and rehabilitation therapies, such as physiotherapy and speech therapy, are crucial for maximizing recovery.

Surgical interventions

• Carotid Endarterectomy Surgical - removal of atherosclerotic plaques from the carotid arteries can restore proper blood flow to the brain, reducing the risk of stroke.

• EC-IC Bypass - When a blood vessel is completely blocked, an external-to- internal carotid bypass can be performed to improve blood flow to the brain, helping prevent further strokes.

• Mayo-syn-angiosis - For cases where blood vessels cannot be reopened, muscle transfer techniques can be used to revascularize the brain.

• Decompressive Craniotomy - In cases of severe brain swelling following a stroke, decompressive surgery may be necessary to reduce pressure within the skull and prevent further damage.

• Microsurgery and Endovascular Techniques - Aneurysms in the brain can be treated with microsurgical clipping or endovascular coiling to prevent re- rupture and ensure the patient's safety.

To conclude

Proactive screening for stroke risk factors, early detection, and timely treatment can significantly reduce the risk of a brain stroke. For those who have already experienced a stroke, ongoing management and rehabilitation are vital to prevent recurrence and enhance recovery. By adopting a healthy lifestyle and staying vigilant about potential symptoms, individuals can greatly reduce their risk of experiencing a brain stroke.

• Diabetes and stroke are deeply intertwined, with a 3 per cent annual increase in risk of stroke per year of Diabetes duration.

• Microvascular damage can develop before the clinical onset of Diabetes and worsen with deteriorating glucose tolerance, supporting early management to lower CV risk.

• Diabetes and hyperglycaemia are risk factors for poor neurological outcome in ischaemic and haemorrhagic stroke.

• A multidisciplinary approach should be encouraged, with the dual aim of limiting the negative impact of hyperglycaemia in the hyperacute setting and tailoring preventive strategies to people with Diabetes

Dr Prashant Bhalekar is Consultant

Intensivist and Head of Critical Care and In-Patient Department