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.