Opsoclonus Myoclonus Syndrome (OMS)
Opsoclonus Myoclonus Syndrome
- The syndrome characteristically involves opsoclonus, myoclonus, and ataxia, and additional behavioral changes.
- Opsoclonus: conjugate, chaotic eye movements in any direction.
- Myoclonus: limb jerks.
- Ataxia: large movement incoordination.
- Personality changes: Irritability and other behavioral changes
- Sleep disturbance.
Causes in Adults
- Paraneoplastic
- Anti-Ri (ANNA-2) anti-neuronal antibody
- Parainfectious
- HIV
- Toxic/metabolic
- Autoimmune
Paraneoplastic Causes
- Anti-Ri (ANNA-2) is the primary paraneoplastic antibody associated with OMS.
- It is an anti-neuronal antibody.
- Cancers that have been found to emit anti-Ri and cause OMS:
- Breast cancer
- Ovarian cancer
- Small cell lung cancer
- Renal cell
- Gastric adenocarcinoma
OMS in Children: Association with Neuroblastoma
- Opsoclonus-myoclonus is a rare presentation of neuroblastoma.
- When opsoclonus-myoclonus ataxia syndrome presents in children, it is often (~50%) due to neuroblastoma, as opposed to in adults where it's typically due to paraneoplastic or parainfectious causes.
References
- Fanous, Ibrahim, and Patrick Dillon. “Paraneoplastic Neurological Complications of Breast Cancer.” Experimental Hematology & Oncology 5 (October 24, 2016). https://doi.org/10.1186/s40164-016-0058-x.
- Klaas, James P., J. Eric Ahlskog, Sean J. Pittock, Joseph Y. Matsumoto, Allen J. Aksamit, J. D. Bartleson, Rajeev Kumar, Kathleen F. McEvoy, and Andrew McKeon. “Adult-Onset Opsoclonus-Myoclonus Syndrome.” Archives of Neurology 69, no. 12 (December 2012): 1598–1607. https://doi.org/10.1001/archneurol.2012.1173.
- Samuels, Martin A., Allan H. Ropper, and Joshua Klein. Adams and Victor’s Principles of Neurology 10th Edition. McGraw-Hill Education, 2014.