LETTERS Treatment responsive

opsoclonuseataxia associated with ovarian teratoma Opsoclonuseataxia syndrome (OAS) is characterised by the subacute onset of ataxia and involuntary chaotic saccades occurring in all directions of gaze. OAS is often accompanied by myoclonus and may result from paraneoplastic, parainfectious and idiopathic aetiologies. Paraneoplastic OAS may be caused by neuroblastoma in children, and small cell lung carcinoma or breast cancer with anti-Ri antibodies in adults.1 We report here a patient with ovarian teratoma and a treatment respon-sive paraneoplastic OAS with subclinical supratentorial hypoperfusion on single photon emission computed tomography (SPECT). CASE REPORT A 24-year-old woman developed abdominal pain and vertigo with unstable gait in the absence of any preceding infection. Findings on CT of the abdomen indicated a left ovarian tumour, 13 cm in diameter. Routine laboratory studies showed no elevations in levels of carcinoembryonic antigen, a-feto-protein or carbohydrate antigen 125. The patient underwent unilateral salpingo-oophorectomy and removal of a teratoma that contained tissues derived from the three embryological layers without immature features, including a dense meshwork of astrocytes, small mature neurons, numerous axons positive for phosphorylated neurofila-ment and catecholaminergic neurons (figure 1A, B). Following tumour resection she continued to have severe vertigo and unsteady gait and was referred to our neurological unit. Neurological examination showed opsoclonus, truncal ataxia and generalised hyporeflexia without myoclonus or memory deficits, and the patient was confined to bed. Analysis of the CSF showed no pleocytosis, normal glucose and protein concentrations, and normal levels of cyto-kines and chemokines, including interleuki