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.