Adult onset opsoclonus-myoclonus-ataxia syndrome, clinical features and diagnostic findings

Abstract

Opsoclonus-myoclonus-ataxia (OMA) is a rare neurological disorder, of paraneoplastic, infectious, post-infectious, post-vaccinal or idiopathic origin. We report a 20-year-old woman who was presented with vertigo, nausea, gait unsteadiness and movement disorders of limbs and eyes. On examination, she had OMA syndrome. Brain MRI and total body scan were normal. Standard biological examinations and cerebro-spinal fluid (CSF) analysis were normal. Serum and CSF viral serology (EBV, VZV, HSV, CMV) were negative. Onco-neural antibodies were negative. Neuron specific enolase was elevated (50,7ng/ml then 60 ng/ml after 2 weeks). The dosage of urinary catecholamines was negative. Our patient received a steroid therapy and had a good outcome. One month later, our patient presented a disseminated intravascular coagulation leading rapidly to death. The autopsy showed a severe and complete loss of Purkinje cells of the cerebellar cortex. It showed also a macroscopic lesion, and the anatomopathological study showed adenomatous nodular hyperplasia of the adrenal glands. This aspect is highly suggestive of a neuroblastoma. OMA syndrome is a rare neurological disorder witch affects mainly children. It is an autoimmune disease caused by dysfunction in Purkinje cells. The etiology varies, although it is a paraneoplastic manifestation (mainly of neuroblastoma) in 40% to 80% of cases. The pathophysiology is thought to be immunological. Therapeutic benefit has been described with steroids, intravenous immunoglobulin, cyclophosphamide, azathioprine, and rituximab. Successful treatment of the tumor, when present, does not usually improve neurological outcome.