University of Auckland neuroscientist Dr Helen Murray joined forces with scientists at the United States government research agency National Institute of Health (NIH), to unravel the mysteries of how Covid-19 impacts the brain, including how it affects sense of smell, Stuff reports. The team viewed samples of brain tissue from deceased Covid-19 patients and found that, while Covid-19 is primarily a respiratory disease, estimates show that one third of hospitalised patients have neurological symptoms, including dizziness and headache. Strokes may also occur in as many as 5 percent of hospitalised patients, studies suggest.