Covid-19 'stroke' deals a cognitive blow

A number of Covid-19 patients may be at the risk of a cerebrovascular accident — or stroke — as neurologists at several city hospitals have each had at least a dozen cases suffering from such conditions in the past three months.

The coronavirus has been found to increase the chances of blood clotting in the brain. When the patients' inflammatory markers in the blood were observed on various days of recovery, the levels were found to be heightened.

Dr Satish Rudrappa, Director of Neurosceinces, Sakra World Hospital, said, "In just three months, I have seen eight Covid patients — either in their recovery phase or two-three weeks after recovery — who came in with a stroke."

Their blood vessels have a reaction, mostly in the deeper part of the brain which is debilitating for them, he said. "We have had both types of patients: those who have diabetes and hypertension, and healthy youngsters who contracted Covid-19 and suffered a stroke."

Rudrappa said those who are obese with diabetes and hypertension are more likely to have a cytokine release, which has an indirect effect on blood vessels and leads to development of clots.

Some of these patients are left with permanent cognitive impairment:

Cognitive functions

"These stroke patients have had hemiplegia, a condition caused by brain damage that leads to paralysis on one side of the body. It causes weakness. They have prolonged stays at the hospital where one hemisphere of the brain does not work. It not only affects cognitive function but causes functional disability too. Most of it is permanent depending on which blood vessels are involved. If the arm and leg are affected on the left side, speech gets affected too. One of my patients will never speak again. These eight recovered Covid patients are significantly disabled," Rudrappa added.

Dr Suryanarayan Sharma, HOD, Neurology, Apollo Hospital, Bannerghatta Road, said that strokes either happened while the patients were still recovering from Covid or after recovery. "We did angioplasty of the brain in Covid-positive patients and gave clot-busting medication to others. Three of our neurologists have, in all, seen 14 Covid patients suffering from strokes since June," he said.

Patients complained of numbness and tingling (neuropathy) as nerves can become weak after Covid, Sharma explained. Post Covid GB syndrome is also common, he said, where there is an allergic reaction and serious nerve damage caused by a viral infection.

Bell's palsy (facial nerve weakness) because of Covid has also been observed. "Our migraine patients who have been on medication for two years suddenly see worsening of symptoms and test positive for Covid. One such patient had seizures post recovery. Covid can have varied neurological implications," Sharma said.

While left-sided stroke will cause speech difficulty and memory loss, right-sided stroke will cause behavioural changes.

Dr Sanjiv CC, senior neurologist, Bhagwan Mahaveer Jain Hospital, said he had treated 15 Covid patients in the past few months and the immune-mediated response to the disease caused strokes, delirium, encephalopathy and seizures in his patients.

Dr Anoop Amarnath, member of the Critical Care Support Unit, said since Covid-19 causes hyper coagulable state, a condition in which there is an abnormally increased tendency towards blood clotting, anti-coagulation is a standard treatment recommended for such patients. He said that after recovery, post viremic pyrexia (fever) and persistent headaches were the most common neurological effects of Covid.