Summary: 60% of 400 coronavirus survivors experienced lasting cognitive impairment, a new study reports. Cognitive problems were found in those who experienced mild-to-moderate COVID symptoms, as well as those who experienced more severe symptoms. One in three of the survivors experienced severe cognitive symptoms, akin to dementia.

In a sample of over 400 older adults in Argentina who had recovered from COVID-19, more than 60% displayed some degree of cognitive impairment, a researcher from The University of Texas Health Science Center at San Antonio reported July 29 at the Alzheimer’s Association International Conference.

It is not known whether the impairment, such as forgetfulness and language difficulty, will be progressive, said Gabriel de Erausquin, MD, PhD, a neurologist with the health science center’s Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases. The individuals in the study are over 60 years of age and have been assessed once so far. They will be followed for the next three to five years, Dr. de Erausquin said.

The study is being conducted by Dr. de Erausquin and collaborators from the Alzheimer’s Association-led global Cognitive Neuropsychiatric Sequelae of SARS-CoV-2 (CNS SC2) consortium.

Problems with thinking were seen even in recovered COVID-19 patients who had only a mild cold or respiratory ailment after virus exposure, Dr. de Erausquin said.

The study team also assessed participants for anosmia, loss of the sense of smell. The olfactory bulb, which contains the brain cells that react to smell, is primarily where the COVID-19 virus enters the nervous system, Dr. de Erausquin said.