COVID-19-related anosmia is driven by inflammation and myelin alterations as shown by Voxel Based Analysis

Motivation: Voxel Based Analysis (VBA) can be a powerful tool to detect localized alterations. Goal(s): Here VBA was used to understand the underpinnings of COVID-19-related anosmia. Approach: Quantitative magnetization transfer and diffusion-weighted imaging derived maps were used to detect pathological changes affecting white matter structures. Results: Microstructural differences were detected between healthy controls and subjects experiencing anosmia or those who recovered from it. Results highlighted the presence of widespread inflammation in persistent anosmia subjects, with myelin damage and possible repair in those who recovered. Myelin alterations involved the olfactory circuit, as well as other brain regions, providing insights into possible mechanisms of COVID-19-related anosmia. Impact: Voxel Based Analysis is a powerful tool to highlight local tissue disruption linked to neuroinflammatory processes. Here VBA provided an insight into microstructure and myelin changes associated to COVID-19-related persistent or recovered anosmia symptoms.