Opsoclonus-Myoclonus syndrome.

1 of 1 DESCRIPTION Opsoclonus-Myoclonus syndrome is a rare dyskinesia due to an underlying infectious, metabolic or neoplastic process. 1 It is frequently caused by neuroblastoma in children and breast or lung carcinoma in adults. It is characterised by high amplitude, multidirectional, arrhythmic and conjugate ocular saccadic intrusions without intersaccadic latency causing oscillopsia 2 and it is associated with myoclonus of axial and/or apendicular musculature 3 and ataxia. Autoimmune dysfunction of Purkinje cells in the dorsal vermis and subsequent disinhibition of oculomotor fastigial region seems to be the most probable mechanism. 4 A 53-year-old female, diagnosed with breast carcinoma 21⁄2 years before the fi rst ophthalmologic assessment. She had refused mastectomy and had nausea, vomiting and cerebellar gait ataxia followed by dysarthria, opsoclonus-related oscillopsia (could not read) and cervical myoclonus. The syndrome was exacerbated by tactile, sound or bright light stimuli and reduced by convergence ( video 1 ). The patient was submitted to left radical mastectomy and monthly chemotherapy (adriamicin 60 mg/m 2 and ciclophosphamide 600 mg/m 2 ). Due to persistence of the opsoclonus-myoclonus syndrome with severe gait ataxia, intravenous immunoglobulin (IVIG), 2 g/kg, was started. Progressive improvement of oscillopsia and complete remission of opsoclonus was evident. Six months after initiating therapy, she had complete remission of the myoclonic component. Mild broad base gait is at the moment, possible without aid. We report a severe Opsoclonus-Myoclonus syndrome starting 21⁄2 years after breast carcinoma. Mastectomy and adjuvant chemotherapy were essential in stabilising the underlying pathologic mechanism but the immune-modulating action of IVIG seems to be helpful since clinical improvement was observed after initiating therapy with complete remission after 6 months.