New guidance for patients
Commenting for this news organization, Davangere P. Devanand, MD, professor of psychiatry and neurology and director of geriatric psychiatry, Columbia University Irving Medical Center, New York, said the findings indicate the damage from COVID in the olfactory pathway may not be reversible as was previously thought.
“This has been suggested before as a possibility, but the autopsy findings in this case series indicate clearly that there may be permanent damage,” he said.
The results highlight the need to monitor patients with COVID for a smell deficit, said Dr. Devanand.
“Assuring patients of a full recovery in smell and taste may not be sound advice, although recovery does occur in many patients,” he added.
He praised the study design, especially the blinding of raters, but noted a number of weaknesses, including the small sample size and the age and gender discrepancies between the groups.
Another possible limitation was inclusion of patients with Alzheimer’s and Lewy body pathology, said Dr. Devanand.
“These patients typically already have pathology in the olfactory pathways, which means we don’t know if it was COVID or the underlying brain pathology contributing to smell difficulties in these patients,” he said.
He noted that, unlike deceased COVID cases in the study, patients who survive COVID may not experience axonal and microvascular injury in olfactory neurons and pathways and their sense of smell may make a full return.
Dr. Devanand said he would have liked more detailed information on the clinical history and course of study participants and whether these factors affected the pathology findings.
The study was supported by grants from the National Institutes of Health.
Dr. Ho and Dr. Devanand have reported no relevant financial disclosures.
A version of this article first appeared on Medscape.com.