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.

Late-onset cobalamin C disease: rare but treatable.

Cobalamin C disease is the most common inborn error of cobalamin metabolism, resulting from mutations in methylmalonic aciduria and homocystinuria type C protein (MMACHC) gene. There is associated elevation of homocysteine and methylmalonic acid and decreased synthesis of methionine. It is a multisystem disorder characterised by cognitive impairment, psychiatric manifestations, haematological manifestations and thromboembolic phenomena. Its variable clinical presentation and wide age distribution at presentation necessitates a high index of diagnostic suspicion. The diagnosis is suggested by amino acid chromatography and confirmed by sequencing analysis of the MMACHC gene Parenteral hydroxycobalamin and betaine can bring significant clinical and biochemical improvement and is the recommended long-term therapy.