Gray matter is vital for processing information in the brain, enabling individuals to control movement, memory, and emotions.

Covid-19 is not only a respiratory infection but takes a toll on the brain too and is linked to reduced gray matter, neurologists have warned.

The reduction in gray matter volume has been witnessed in the frontal lobe of the brain in severe Covid-19 patients with fever and requiring oxygen therapy, a small study conducted by researchers at Georgia State University has found. The study has been published in the journal Neurobiology of Stress.

“People with severe cases of Covid-19 who require oxygen and/or ventilator support with prolonged hospitalisation seem to be at a higher risk of developing neurological symptoms,” Dr Pavan Pai, neurologist, Wockhardt Hospital, told IndiaToday.in.

Gray matter is vital for processing information in the brain, enabling individuals to control movement, memory, and emotions. Gray matter abnormality may affect functioning of neurons and communication.

‘Those with pre-existing brain disorders more at risk’

Padma Shri awardee Dr BN Gangadhar, Director of National Institute of Mental Health and Neurosciences (NIMHANS), said such an outcome was likely to be seen in those with pre-existing brain disorders and co-morbidities like hypertension and obesity.

“Contracting Covid-19 has nothing to do with your brain being small or big. But once you get Covid-19, those with smaller brains are likely to have a poorer outcome. Lesser gray matter is another risk factor for poorer outcome,” Dr BN Gangadhar told IndiaToday.in.ADVERTISEMENT

Dr Pavan Pai said that low gray matter volume in the brain was linked with a higher level of disability among Covid-19 patients.

“Reduced gray matter is also seen in mood disorders which explains how it causes mood swings and anxiety issues in Covid-recovered patients,” he said.

Proper sleep, managing stress key

In such scenarios, Dr Pai suggested that everyone should watch for “abnormal symptoms” after recovering from Covid-19 and go for regular follow-ups with the doctor for appropriate treatment.

“Brain manifestations post Covid-19 can be avoided by sleeping 8 to 9 hours per night, managing stress, exercising, managing Diabetes mellitus and blood pressure, strengthening brain power by solving brain puzzles, finding enjoyable activities, increasing intake of protein, fruits vegetables and healthy fats,” he said.

Covid alone responsible for reduction in gray matter?

However, Dr Mukesh Kumar, associate director, Department of Neurology, Max Hospital, said it was difficult to say if Covid-19 alone was responsible for reduction in gray matter in the brain.

This needs to be validated by studies on a larger sample size than the one conducted by researchers at Georgia State University, he said. The study analysed CT scans in 120 neurological patients, including 58 with acute Covid-19 and 62 without Covid-19.

” Severe Covid-19 patients who require oxygen generally display agitation, psychotic reaction, abnormal behaviour. This is very common. Moreover, a reduction of gray matter in the frontal lobe has also been shown to be present in other disorders such as schizophrenia, psychosis or obsessive-compulsive disorder (OCD). These factors deteriorate in Covid-19 patients,” Dr Mukesh Kumar said.

Researchers said around 15 per cent of Covid-19 patients requiring hospitalisation experience neurological complications.

The most common manifestations are insomnia, metabolic encephalopathy, stroke, lack of smell and taste sensations, muscle and neuropathic pain. Other manifestations such as encephalitis, epilepsy, Guillain-Barre syndrome, brain fog, confusion and mood swings have also been witnessed in a few patients having severe Covid-19 symptoms.