Clinical heterogeneity in patients with myoclonus associated to COVID-19

De Novo Movement Disorders Associated with COVID-19- A Systematic Review of Individual Patients

Background

COVID-19 infection is associated with neurological manifestations, including various types of movement disorders (MD). A thorough review of individual patients with COVID-19-induced MD would help in better understanding the clinical profile and outcome of these patients and in prognostication.

Objective

We conducted an individual patient-systematic review to study the clinical and imaging profile and outcomes of patients with COVID-19-associated MD.

Methods

A systematic literature search of PubMed, EMBASE, and Cochrane databases was conducted by two independent reviewers. Individual patient data COVID from case reports and case series on COVID-19-associated MD, published between December 2019 and December 2022, were extracted and analyzed.

Results

Data of 133 patients with COVID-19-associated MD from 82 studies were analyzed. Mean age was 55 ± 18 years and 77% were males. A mixed movement disorder was most commonly seen (41%); myoclonus-ataxia was the most frequent (44.4%). Myoclonus significantly correlated with age (odds ratio (OR) 1.02 P = 0.03, CI 1-1.04). Tremor had the longest latency to develop after SARS-CoV-2 infection [median (IQR) 21 (10-40) days, P = 0.009, CI 1.01-1.05]. At short-term follow-up, myoclonus improved (OR 14.35, P value = 0.01, CI 1.71-120.65), whereas parkinsonism (OR 0.09, P value = 0.002, CI 0.19-0.41) and tremor (OR 0.16, P value = 0.016, CI 0.04-0.71) persisted.

Conclusion

Myoclonus-ataxia was the most common movement disorder after COVID-19 infection. Myoclonus was seen in older individuals and usually improved. Tremor and parkinsonism developed after a long latency and did not improve in the short-term.

Cerebrospinal Fluid Anti-Neuronal Autoantibodies in COVID-19-Associated Limbic Encephalitis with Acute Cerebellar Ataxia and Myoclonus Syndrome: Case Report and Literature Review

Since the outbreak of coronavirus (COVID-19) in 2019, various rare movement disorders and cognitive changes have been recognized as potential neurological complications. The early treatment of some of these allows rapid recovery; therefore, we must diagnose these manifestations in a timely way. We describe the case of a 76-year-old man infected with severe acute respiratory syndrome coronavirus-2 who presented with confusion and hallucinations and was admitted to our hospital 14 days after the onset of symptoms. One day later, he developed generalized myoclonus, dysarthria and ataxia, and tonic clonic seizures and was admitted to the intensive care unit. A diagnosis of COVID-19-associated autoimmune encephalitis with characteristics of limbic encephalitis and immune-mediated acute cerebellar ataxia and myoclonus syndrome was supported by alterations in the limbic system shown in magnetic resonance imaging, lateralized discharges shown in electroencephalography, a slightly elevated protein level in the cerebrospinal fluid (CSF), and indirect immunofluorescence in the CSF with autoantibody binding to anatomical structures of the cerebellum and hippocampus. The patient improved with 2 weeks of corticosteroid treatment and four sessions of plasmapheresis. Our current case study describes a rare case of COVID-19-related limbic encephalitis with immune-mediated acute cerebellar ataxia and myoclonus syndrome (ACAM syndrome) and strengthens the need for tissue-based assays (TBAs) to screen the serum and/or CSF of patients highly suspected to have autoimmune encephalitis. We believe that the timely diagnosis and targeted aggressive immunotherapy were mainly responsible for the patient's total recovery.