Category: Myoclonus/Tics/Stereotypies
Objective: To describe the phenomenology, etiology and treatment response in adults presenting to our clinic with myoclonus.
Background: Myoclonus in the inpatient setting range often occurs from toxic-metabolic and hypoxic-ischemic causes1. Outpatient myoclonus in previous reports is predominantly due to neurodegenerative conditions.2
Method: We retrospectively reviewed charts of outpatient adults with myoclonus at New York Presbyterian Brooklyn Methodist Hospital between 2011 and 2021. Data were analyzed with descriptive statistical methods to elucidate demographics and outcomes.
Results: 85 individuals, 52.9% female, aged 64.3 + 16.3 years, were included in our study. Our cohort consisted of a predominantly Caucasian (42.4%), Black (32.9%), and Hispanic (9.41%) population. Longer symptom duration was prevalent in outpatient cases. In terms of etiology, neurodegenerative conditions such as Lewy Body Disease and Alzheimer’s Disease, autoimmune diseases such as opsoclonus-myoclonus syndrome, and idiopathic causes were more prevalent in the outpatient setting. Focal myoclonus was due to spinal or iatrogenic causes and axial myoclonus more likely from autoimmune causes. Responses to treatment of underlying etiology and/or anti-seizure drugs was robust in the outpatient setting, with over 70% of individual cases responding to treatment, with levetiracetam being the most used symptomatic treatment.
Conclusion: Myoclonus in the outpatient setting is commonly due to neurodegenerative and autoimmune causes and has a long duration of presentation in our cohort. Treatment response was robust. Additional studies in larger cohorts amongst different ethnic groups are needed to confirm our results.
References: 1. Oh K, Hamed M, Zarandi D, Oluleye M, Zaher A, Elsayegh J, Rizly S, Ma X, Ooi H, Sarva H, Salgado M, Victor D. 2025. Adult-onset Myoclonus in a large urban inpatient setting: a retrospective cohort study. Tremor and Other Hyperkinetic Movements, 15(1):2, pp. 1-8. DOI: 10.5334/tohm.977.
2. Caviness J, Brown P. 2004. Myoclonus: current concepts and recent advances. Lancet Neurology, 3(10):598-607.
To cite this abstract in AMA style:
M. Hamed, K. Oh, D. Zarandi, M. Oluleye, A. Zaher, J. Elsaygh, S. Rizly, X. Ma, H. Ooi, H. Sarva, M. Salgado, D. Victor. Retrospective series of adult-onset myoclonus presenting to an outpatient movement disorders clinic [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/retrospective-series-of-adult-onset-myoclonus-presenting-to-an-outpatient-movement-disorders-clinic/. Accessed November 20, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/retrospective-series-of-adult-onset-myoclonus-presenting-to-an-outpatient-movement-disorders-clinic/