Akinetic Mutism and Coronavirus Disease 2019: A Narrative Review

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been associated with neuropsychiatric complications ranging from new-onset psychosis to delirium, dysexecutive syndromes, catatonia, and akinetic mutism (AM). AM can be conceptualized as a disorder of motivation wherein patients exhibit a loss of speech and spontaneous movement, owing to disruption of underlying frontal-subcortical circuits. OBJECTIVES: The objectives of this study were to review the concept and differential diagnosis of AM, as well as the clinical literature on AM in COVID-19 and discuss potential implications for underlying functional neuroanatomy and mechanistic pathways, as well as clinical management. METHODS: A narrative literature review was performed using PubMed querying published articles for topics associated with AM and its occurrence in COVID-19. RESULTS: AM has been described in case reports and a prospective cohort study of patients with COVID with neurological complaints. Three COVID-19 AM subgroups can be distinguished, including individuals with severe respiratory illness, those with meningoencephalitis, and those with delirium and pre-existing neuropsychiatric illness. Electrophysiology and functional imaging suggest COVID-19 AM may result from underlying frontal lobe dysfunction and disruption of associated distributed circuits subserving goal-directed behavior. Distinctive combinations of pathophysiological mechanisms may be at play in the different subgroups of COVID-19 AM cases. CONCLUSION: AM has been described in association with COVID-19 and may manifest in clinically heterogenous subgroups with distinct underlying mechanisms. The diagnosis of AM and evaluation of potential etiologies can be complex. The occurrence of AM contributes evidence to the hypothesis of frontal lobe dysfunction in COVID-19.