[Transient myoclonic state with asterixis related to COVID-19]

A 64-year-old Japanese man presented with flu-like symptoms and received a diagnosis of COVID-19 (day 1). The patient developed sudden-onset involuntary movements in his trunk, left upper limb, and face (day 7). On examination (day 8), myoclonus was observed on the bilateral upper limbs and the trunk. Asterixis was also noted on the bilateral hands at the dorsiflex position of the wrists. Other neurological manifestations were unremarkable. After initiation of oral clonazepam (1.5 ‍mg/day) administration, the involuntary movements vanished within several hours. No recurrence of the neurological symptoms, including any involuntary movements, was observed afterwards. Based on the clinical course, the patient was diagnosed with transient myoclonic state with asterixis (TMA) associated with COVID-19. Respiratory infections could cause TMA; however, there have been no clinical reports of TMA caused by COVID-19. Hypercytokinemia followed by COVID-19 and immune reaction against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can be related to transient dysfunction of the central nervous system, such as motor cortex, brain stem, and hypothalamus, which could be associated with development of TMA.