Generalized myoclonus in COVID-19.

Rábano-Suárez, Pablo; Bermejo-Guerrero, Laura; Méndez-Guerrero, Antonio; Parra-Serrano, Javier; Toledo-Alfocea, Daniel; Sánchez-Tejerina, Daniel; Santos-Fernández, Teresa; Folgueira-López, María Dolores; Gutiérrez-Gutiérrez, Judit; Ayuso-García, Blanca; González de la Aleja, Jesús; Benito-León, Julián

OBJECTIVE To report 3 patients infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) who developed generalized myoclonus. METHODS Patient data were obtained from medical records from the University Hospital "12 de Octubre," Madrid, Spain. RESULTS Three patients (2 men, and one woman, aged 63-88) presented with mild hypersomnia and generalized myoclonus following the onset of the so-called "inflammatory" phase of coronavirus disease 2019 (COVID-19). All of them had presented previously with anosmia. Myoclonus had a stereotypical pattern, being both positive and negative, generalized, with a predominant involvement of nasopharyngeal, facial, and upper limbs areas. These jerky movements occurred spontaneously and were extremely sensitive to multisensory stimuli (auditive and tactile) or voluntary movement, with an exaggerated startle response. Other causes of myoclonus were ruled-out, and none of them had undergone respiratory arrest or significant prolonged hypoxia. All of them improved, at least partially, with immunotherapy. CONCLUSIONS Our 3 cases highlight the occurrence of myoclonus during the COVID-19 pandemic as a postinfectious/immune-mediated disorder. However, we cannot rule out that SARS-CoV-2 may spread transneuronally to first- and second-order structures connected with the olfactory bulb. Further investigation is required to clarify the full clinical spectrum of neurologic symptoms and its optimal treatment.