Clinical heterogeneity in patients with myoclonus associated to COVID-19

OBJECTIVE: This study aims to report the clinical heterogeneity of myoclonus in 6 patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Patient data were obtained from medical records from the University Hospital Dr. Josep Trueta, Girona, Spain. RESULTS: Six patients (5 men and 1 woman, aged 60–76 years) presented with different myoclonus phenotypes. All of them had a medical history of hypertension and overweight. The latency of myoclonus appearance ranged from 1 to 129 days. The phenotype most observed was generalized myoclonus. Special phenotypes such as painful legs and moving toes syndrome with jerking feet, Lazarus sign-like, action myoclonus/ataxia syndrome, and segmental myoclonus secondary to myelitis have been described too. Levetiracetam and clonazepam were medications most used successfully. Two patients died for complications not related to myoclonus. CONCLUSIONS: Our 6 cases highlight the heterogeneity of the clinical spectrum of myoclonus associated to COVID-19 (MYaCO). MYaCO pathogenesis is suspected to be due to an immune-mediated para- or post-infectious phenomenon; nevertheless, further research is needed to elucidate this hypothesis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10072-021-05802-1.