Olfactory Bulb Signal Abnormality in Patients with COVID-19 Who Present with Neurologic Symptoms

Normalized OB T2 FLAIR signal intensity in patients and controls. Box-and-whisker plots show median and interquartile ranges for each group. There was a significant difference in mean signal intensity between the patients and the controls (P = .003). Findings remain significant even with the exclusion of the COVID-19 high outlier depicted at a mean normalized OB T2 FLAIR signal intensity of 3.1.

A 48-year-old woman positive for COVID-19 who presented with weakness and unsteady gait of 1 week’s duration. Neurologic examination was significant for truncal ataxia, dysarthria, and left-sided dysmetria. A, Coronal high-resolution T2WI demonstrates normal OB morphology and signal intensity. B, Coronal and (C) sagittal postcontrast T2 FLAIR images demonstrate an increased T2 signal within the OB (red arrows). Note relative increased signal compared with (D) coronal T2WI at the level of the intracisternal segment of the trigeminal nerve (red arrow).

A 52-year-old woman positive for COVID-19 and with a history of major depressive disorder, was found to be catatonic. A, Coronal and (B) sagittal postcontrast 3D T2 FLAIR demonstrates increased intraneural signal within the OBs (red arrows) relative to (C) coronal postcontrast 3D T2 FLAIR images of the trigeminal nerve (red arrow).