What does COVID-19 do to brain?

LONDON: Stroke, delirium, anxiety, confusion, fatigue - the list goes on. If you think Covid-19 is just a respiratory disease, think again, foreign media reported.

As each week passes, it is becoming increasingly clear that coronavirus can trigger a huge range of neurological problems. Several people who've contacted me after comparatively mild illness have spoken of the lingering cognitive impact of the disease - problems with their memory, tiredness, staying focused.

But it's at the more severe end that there is most concern.

Chatting to Paul Mylrea, it's hard to imagine that he had two massive strokes, both caused by coronavirus infection.

The 64-year-old, who is director of communications at Cambridge University, is eloquent and, despite some lingering weakness on his right side, able-bodied.

He has made one of the most remarkable recoveries ever seen by doctors at the National Hospital for Neurology and Neurosurgery (NHNN) in London

His first stroke happened while he was in intensive care at University College Hospital. Potentially deadly blood clots were also found in his lungs and legs, so he was put on powerful blood-thinning (anticoagulant) drugs.

A couple of days later he suffered a second, even bigger stroke and was immediately transferred to the NHNN in Queen Square Consultant neurologist Dr Arvind Chandratheva was just leaving hospital when the ambulance arrived.

"Paul had a blank expression on his face,” he says. “He could only see on one side and he couldn't figure out how to use his phone or remember his passcode.

"I immediately thought that the blood thinners had caused a bleed in the brain, but what we saw was so strange and different."

Paul had suffered another acute stroke due to a clot, depriving vital areas of the brain of blood supply.

Tests showed that he had astonishingly high levels of a marker for the amount of clotting in the blood known as D-dimer. Normally these are less than 300, and in stroke patients can rise to 1,000. Paul Mylrea's levels were over 80,000.

“I've never seen that level of clotting before - something about his body's response to the infection had caused his blood to become incredibly sticky,” says Dr Chandratheva.

During lockdown there was a fall in the number of emergency stroke admissions. But in the space of two weeks, neurologists at the NHNN treated six Covid patients who'd had major strokes. These were not linked to the usual risk factors for stroke such as high blood pressure or diabetes. In each case they saw very high levels of clotting.

Part of the trigger for the strokes was a massive overreaction by the immune system which causes inflammation in the body and brain.

Dr Chandratheva projected Paul's brain images on a wall, highlighting the large areas of damage, shown as white blurs, affecting his vision, memory, coordination, and speech.

The stroke was so big that doctors thought it likely he would not survive, or be left hugely disabled.

“After my second stroke, my wife and daughters thought that was it, they would never see me again,” Paul says. “The doctors told them there was not much they could do except wait. Then I somehow survived and have been getting progressively stronger.”