BENGALURU : The pandemic is still active and progressive in many ways. Though significant numbers have recovered, the long-term implications are yet to be understood. Viruses are small particles whose origin remains controversial, yet their ability to survive in other beings changes suitably to circumstances and ability to modify constantly makes them unique and unpredictable.
The Covid-19 infection is known to cause acute respiratory distress syndrome and a hyper immune response called cytokine storm. Recent accumulated evidence also shows that Covid-19 infection is an independent risk factor for stroke. A new onset of brain stroke is noted in 5.9 per cent of Covid patients. Among the neurological complications of Covid, stroke is the leading one by 85 per cent. Large blood vessels are affected in majority contributing to 46 per cent of the strokes.
The average time of onset of stroke is 12 days from the start of the infection. Among the people who have the high risk for stroke, like those with diabetes, high blood pressure, abnormal lipids in the blood, etc, the stroke risk increases 2.5 fold. The occurrence of stroke in Covid infection increases the risk of death, ICU stay as well as ventilator assistance. Presence of active pneumonia is an added risk factor.
Presence of hypercoagulable state with an increased tendency for the blood to form a clot in these patients can explain the increased risk of strokes. Normally, clotting mechanism of the body gets activated only when needed, like in injury. Spontaneous clotting occurs in Covid infection within the blood vessels. Presence of arterial clots have been described in 3.7 per cent of patients and large vessel occlusion causing massive or multiple strokes. The inflammation associated can cause platelet aggregation as well as damage to the blood vessels, causing bleeding either in pre-existing stroke or independently. A CT scan is diagnostic of the condition. Elderly with associated risk factors for the stroke are at higher risk, and in younger individuals, Covid can be an independent risk for stroke.
Symptoms & treatment
The standard treatment for stroke and the treatment of Covid as per the current guidelines are being combined. They need intense monitoring and aggressive management. What is not clear is the preventive role of medicines used for stroke, and to whom, when and how long to administer. It is important to be vigilant and avoid infection.
If it happens, early detection of any neurological symptoms like numbness, slight weakness, speech difficulty, loss of balance, persistent headache, blurred vision should be taken as warning signs. All the infected, regardless of symptoms, should be screened for the available bio-markers of stroke. This should be implemented for all ages. Those with symptoms of stroke should be admitted to a stroke centre as soon as possible. The author is the founder chairman and chief neurosurgeon, BRAINS Hospital.