Successful use of tacrolimus for treatment-refractory neuroblastoma-associated opsoclonus-myoclonus-ataxia syndrome: A case series

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is an autoimmune central nervous system disorder, primarily manifesting as a paraneoplastic sequalae to neuroblastoma, and characterized by motor disorders and behavioral disturbances. OMAS is typified by aberrant B-cell and T-cell activation. Current treatment involves immunosuppression using corticosteroids, intravenous immunoglobulin, and rituximab. However, these approaches often lead to treatment-related toxicities and symptomatic recurrences with chronic neurocognitive impairment. We treated three children with refractory neuroblastoma-associated OMAS with tacrolimus, a T-cell-targeting calcineurin inhibitor, effectively controlling symptoms within a month and enabling the discontinuation of immunosuppression with minimal side effects. Tacrolimus shows promise as a therapeutic option for refractory OMAS.

Clinical Profile, Prognostic Indicators, and Therapeutic Outcomes of Pediatric Opsoclonus-Myoclonus-Ataxia Syndrome: A Single-Center Experience from South India

Background:

Opsoclonus myoclonus syndrome (OMS) is a neuroinflammatory disorder. Indian literature on its clinical profile and outcome is sparse.

Objectives:

The objective of this study is to describe the clinical profile and analyze outcomes and prognostic predictors in a cohort of children with OMS.

Materials and Methods:

This was a retrospective study of children with OMS between 2007 and 2017.

Results:

Twenty-two children were included in the study. The mean age at onset of symptom was 20.9 months (standard deviation [SD]: 7.5). The mean duration of delay in diagnosis was 8.4 months (SD 1.26) with acute cerebellitis being the most common misdiagnosis. Eleven children (50%) were diagnosed with tumor during evaluation and follow-up and 11 children (50%) belonged to idiopathic/postinfectious group. Magnetic resonance imaging brain was normal in all children except for one revealing cerebellar atrophy on follow-up. One child in the paraneoplastic group (neuroblastoma) had a positive PNMA2/Ta onconeural antibody. Children in the tumor group had an earlier age of onset (mean 15.5 vs. 26.3 months), shorter time to onset of opsoclonus from initial symptom (2.54 vs. 7.27 weeks), and higher severity score at presentation (13.7 vs. 11.3) compared to the nontumor group. Children in the nontumor group attained their first remission with treatment earlier (10.9 weeks, SD: 4.5) than the children with tumor (18.72 weeks, SD: 5.8). There was no significant difference in the outcome between the groups. Children with multiple relapses (>3) and late surgical intervention for tumor (>6 months after symptom onset) had a poor outcome.

Discussion:

A high index of suspicion coupled with early diagnosis and periodic tumor surveillance (even in the initially negative cases) along with aggressive combined multimechanistic immunotherapies is the key in improving outcomes.

Conclusion:

A high index of suspicion in appropriate clinical circumstances and early aggressive immunomodulation might lead to a better outcome.

Neuroblastoma presenting as opsoclonus-myoclonus: A series of six cases and review of literature

The opsoclonus-myoclonus ataxia syndrome (OMAS) also called “Kinsbourne syndrome” or “dancing eye syndrome” is a rare but serious disorder characterized by opsoclonus, myoclonus, and ataxia, along with extreme irritability and behavioural changes. Data on its epidemiology, clinical features, and outcome are limited worldwide. The aim of the study was to evaluate the clinical profile and outcome of children with OMAS. A retrospective data of all children presented to Pediatric oncology clinic with a diagnosis of opsoclonus-myoclonus from 2013 to 2016 were collected. 6 patients with a diagnosis of OMAS were presented over a 4-year period. All 6 cases had paraneoplastic etiology. All Children had good outcome without any relapse. Paraneoplastic opsoclonus myoclonus had a good outcome in our experience.

Pediatric Opsoclonus-Myoclonus-Ataxia Syndrome Associated With Anti-N-methyl-D-aspartate Receptor Encephalitis

BACKGROUND

The full clinical spectrum of anti-N-methyl-D-aspartate receptor encephalitis is unknown in the pediatric population.

PATIENT

We describe a previously healthy 4-year-old girl presenting with opsoclonus-myoclonus together with ataxia who had NR1-specific, anti-N-methyl-D-aspartate receptor antibodies in the cerebral spinal fluid.

CONCLUSION

The presence of NR1-specific, anti-N-methyl-D-aspartate receptor antibodies in the setting of opsoclonus-myoclonus and ataxia syndrome may represent an expansion of the clinical presentations of anti-N-methyl-D-aspartate receptor encephalitis.