The research, based on a study of 153 patients treated in the UK hospitals during the acute phase of the Covid-19, describes a range of neurological and psychiatric complications that may be linked to the disease.
Out of the 153 patients, full clinical details were available for 125 patients, said the study published in the journal The Lancet Psychiatry.
The most common brain complication observed was stroke, which was reported in 77 of 125 patients.
Of these, 57 patients had a stroke caused by a blood clot in the brain, known as an ischaemic stroke, nine patients had a stroke caused by a brain haemorrhage, and one patient had a stroke caused by inflammation in the blood vessels of the brain.
Age data was available for 74 of the patients who experienced a stroke and the majority were over 60 years of age.
"This data represents an important snapshot of the brain-related complications of Covid-19 in hospitalised patients. It is critically important that we continue to collect this information to really understand this virus fully," said co-author of the study, Professor Sarah Pett, from University College London.
"We also need to understand brain-complications in people in the community who have COVID-19 but were not sick enough to be hospitalised. Our study provides the foundations for larger, hospital and community-based studies."
A total of 39 patients showed signs of confusion or changes in behaviour reflecting an altered mental state, said the study.
Of these, nine patients had unspecified brain dysfunction, known as encephalopathy, and seven patients had inflammation of the brain, medically termed encephalitis.
About 23 patients with an altered mental state were diagnosed with psychiatric conditions, of which the vast majority were determined as new diagnoses by the notifying psychiatrist.
Although most psychiatric diagnoses were determined as new by the notifying psychiatrist or neuropsychiatrist, the researchers said they cannot exclude the possibility that these were undiagnosed before the patient developed Covid-19.
The 23 patients with psychiatric diagnoses included 10 patients with a new-onset psychosis and six patients with a dementia-like syndrome.
Seven patients had signs of a mood disorder, including depression and anxiety.
Age information was available for 37 of the 39 patients with an altered mental state and of those, around half were aged under 60 years of age.
Detailed long-term studies are needed in order to confirm if there is any link between Covid-19 infection and the onset of psychiatric or neuropsychiatric complications in younger patients, said the researchers.