Background and objective: Opsoclonus myoclonus ataxia syndrome (OMAS) is a rare autoimmune condition characterised by opsoclonus, myoclonic jerks, behavioral disturbances, and ataxia, and are most often seen in children. Majority have residual motor, speech, cognitive, or behavioral problems on long term. Hence, we aimed to study the clinical profile and outcome in children with OMAS.

Methods: Children satisfying three out of four criteria for OMAS—opsoclonus, ataxia and/or myoclonus, behavioral changes and/or sleep disturbances and neuroblastoma between 2018 and 2023 were included in the study. The demography, clinical profile, investigations, treatment received and outcome were recorded. Descriptive statistics were used for analysis.

Results: Nine patients were included in the study with mean age of onset 18.2 ± 5.6 months and 6 males. Six patients (66.7%) had antecedent febrile illness. Ataxia was the most frequent clinical presentation seen in all children followed by behavioural problems, opsoclonus, myoclonus, and sleep disturbances in 7 (77.8%), 6 (66.7%), 5 (55.6%) and 3 (33.3%) respectively. Three (33.3%) children had neuroblastoma and underwent surgical resection. One patient had high titres of anti GAD antibody. Seven (77.8%) children received both high dose glucocorticoids (GC) and intravenous immunoglobulin (IVIG), whereas only two patients received the front load approach (GC+IVIG+ rituximab). The median duration of followup was 4 years (range, 1-7 years), with relapse in 6 (66.7%) and complete remission in only three children (33.3%).

Conclusion: OMAS has significant long term sequelae with high rate of relapse. Hence, early aggressive and prolonged immunomodulatory therapy is needed.

S Veena
Sree Chitra Tirunal Institute for Medical sciences and Technology
India

Jemini George
Sree Chitra Tirunal Institute for Medical sciences and Technology
India

Krishna Nikhil
Sree Chitra Tirunal Institute for Medical sciences and Technology
India

Sruthi S Nair
Sree Chitra Tirunal Institute For Medical Sciences And Technology
India

Soumya Sundaram
Sree Chitra Tirunal Institute For Medical Sciences And Technology
India