Diagnosis and Management of Opsoclonus-Myoclonus-Ataxia Syndrome in Children

Abstract

Background and ObjectivesOpsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare disorder of the nervous system that classically presents with a combination of characteristic eye movement disorder and myoclonus, in addition to ataxia, irritability, and sleep disturbance. There is good evidence that OMAS is an immune-mediated condition that may be paraneoplastic in the context of neuroblastoma. This syndrome may be associated with long-term cognitive impairment, yet it remains unclear how this is influenced by disease course and treatment. Treatment is largely predicated on immune suppression, but there is limited evidence to indicate an optimal regimen.MethodsFollowing an international multiprofessional workshop in 2004, a body of clinicians and scientists comprising the International OMS Study group continued to meet biennially in a joint professionals and family workshop focusing on pediatric OMAS. Seventeen years after publication of the first report, a writing group was convened to provide a clinical update on the definitions and clinical presentation of OMAS, biomarkers and the role of investigations in a child presenting with OMAS, treatment and management strategies including identification and support of long-term sequelae.ResultsThe clinical criteria for diagnosis were reviewed, with a proposed approach to laboratory and radiologic investigation of a child presenting with possible OMAS. The evidence for an upfront vs escalating treatment regimen was reviewed, and a treatment algorithm proposed to recognize both these approaches. Importantly, recommendations on monitoring of immunotherapy response and longer-term follow-up based on an expert consensus are provided.DiscussionOMAS is a rare neurologic condition that can be associated with poor cognitive outcomes. This report proposes an approach to investigation and treatment of children presenting with OMAS, based on expert international opinion recognizing the limited data available.

Profile and Outcome of Children with Opsoclonus Myoclonus Ataxia: A Tertiary Care Hospital Experience from India

“…Recent studies have suggested utility of rituximab based on the expansion of cerebrospinal fluid B cells in the pathogenesis of OMAS. 3 9 In our study, two children needed rituximab as there was ill-sustained response to steroids and IVIG. However, due to lack of improvement one child (subject 6) was started on pulse dexamethasone and cyclophosphamide monthly for four cycles after which he became ambulatory.…”

“…This has been noted previously and attributed to low grade of the tumor. 3 6 7 This observation is particularly relevant in low- and middle-income countries where cost and availability of MIBG scan and urinary VMA is a constraint. These are likely to add to delay in diagnosis and treatment.…”

“…3 Functional studies with metaiodobenzylguanidine (MIBG) scan and 24-hour urine vanillylmandelic acid (VMA) have been found to have variable results. 3 6 7…”

“…Opsoclonus myoclonus ataxia syndrome (OMAS) is characterized by involuntary random, rapid, conjugate, multidirectional, chaotic eye movements (opsoclonus), limb myoclonus, ataxia (staggering/falling), and behavioral changes (irritability, clinginess, sleep disturbance). [1][2][3] It is often associated with neuroblastoma but also reported with infections and vaccination. [3][4][5] Evaluation for underlying neurogenic tumor is done by structural imaging of neck, thorax, abdomen, pelvis with computed tomography (CT) scan or magnetic resonance imaging (MRI).…”

“…[1][2][3] It is often associated with neuroblastoma but also reported with infections and vaccination. [3][4][5] Evaluation for underlying neurogenic tumor is done by structural imaging of neck, thorax, abdomen, pelvis with computed tomography (CT) scan or magnetic resonance imaging (MRI). 3 Functional studies with metaiodobenzylguanidine (MIBG) scan and 24-hour urine vanillylmandelic acid (VMA) have been found to have variable results.…”