Brain matters

The pandemic may have increased the incidence of stroke but understanding the mechanism of neurological impact of the virus and its relationship with comorbidities can go a long way in averting damage, writes Dr Sudhir Kale

Stroke is a global epidemic within the ongoing Covid-19 pandemic. Stroke terminology worldwide is mainly used to relate blocked blood vessels to the brain resulting in varied manifestations like weakness or numbness in the face, arms, legs or slurring of speech or sudden impairment in vision or a walking imbalance or inability to comprehend or disorientation. Other types of strokes are haemorrhages or stroke-like syndromes due to space-occupying lesions. Worldwide, 20 million people suffer from stroke each year, 5 million will die as a consequence and 15 million will survive. Of those who survive, 5 million will be disabled by their stroke. The Covid-19 pandemic has further increased the incidence of stroke due to the prothrombotic nature of the disease.

Coronavirus causing a stroke is now a well-established entity across the globe with various studies showing that about 1 to 6% of Covid-19 patients developed stroke. As far as India is concerned, stroke continues to be one of the leading causes of disability in this pandemic. Brain vessels are considered to be the next common site for viral attacks after lung vessels. The coronavirus spike proteins bind with ACE receptors on the inside lining of a blood vessel leading to a chain of events that results in a pro-thrombotic state and elevated d-dimer in the blood. In this state, there is an increased tendency of blood to thicken or become sticky lumps called clots which block the vessels supplying to the brain. As the blood supply of the part of the brain gets cut, patients develop stroke symptoms depending on the area of the brain involved.

Don’t ignore symptoms

It has been found that people have avoided getting medical help in the current ongoing pandemic with fear of contracting Covid-19 in hospitals. But one must understand that stroke is a medical emergency that can leave behind a serious disability. The only solution to counter it is getting the necessary treatment at the earliest in a hospital.

As per literature, stroke patients getting treated within a window period of 0 to 4.5 hours are seen to have very good results with minimal disabilities or mortalities. It has been reported that in an untreated large-vessel ischaemic stroke, an average patient loses 1.9 million neurons per minute. This emphasises the phrase “Time is brain” in acute stroke care, just like “Time is muscle” in acute heart attacks, both tracing their lineage to Benjamin Franklin’s original aphorism “Time is money”.

Act FAST

The incidence of stroke has been more in patients with traditional risk factors like elderly patients, uncontrolled blood pressure and diabetes, smoking, high cholesterol etc. However, many reports and studies during this current pandemic have shown a relatively increased occurrence of stroke in young and without any known traditional risk factors. This is a real cause for concern and should not be taken lightly by the younger population.

Stroke can be a first presenting symptom of Covid-19 or can occur during the hospital stay or during the home quarantine of a Covid positive patient or can occur in the immediate post-Covid recovery period. Hence, it is very important to be aware of these conditions. Patients with risk factors should continue their medications as per medical advice and the rest should be aware of early symptoms and seek emergency medical help in time.

A CT scan/MRI helps in detecting stroke accurately. MRI with diffusion-weighted imaging is highly sensitive in detecting early acute stroke. Perfusion imaging is done in some centres to assess the relative cerebral blood flow in the brain. MR Angiography is done to assess the blood vessels that are supplied to the brain. Healthcare systems are overwhelmed with Covid-19 and many hospitals have created stroke teams and dedicated Covid-free zones in the hospital to ensure swift and better emergency care for stroke patients. Vaccinations should be taken as per the guidelines in all age groups above 18 yrs including stroke and post-Covid patients. Do remember to act FAST in a stroke (F: Facial weakness, A: Arm weakness, S: Speech disturbance and T: Do not waste time at home). Truly, the brain matters and timely intervention can save millions of neurons.

(The author is a lead consultant radiologist & HOD at a multi-speciality hospital in Bengaluru.)