Effective high-dose clonazepam treatment in two patients with opsoclonus and myoclonus: GABAergic hypothesis.

both patients have been described in detail elsewhere [5] . Briefly, two consecutive young adults aged 34 and 29 years exhibited repeated vomiting, vertigo, truncal ataxia, opsoclonus and generalized myoclonus. Both deteriorated to the peak of clinical disability 1 month later when they lost the ability to walk and were confined to bed. In both patients, the cellular and humoral CSF alterations were only slight at onset, becoming more pronounced 1 month later. A mononuclear pleocytosis increased within the first month and then normalized during the following weeks. Intrathecally synthesized IgM occurred only transiently after 1 month of illness, whereas intrathecal IgG production increased during the first month and persisted for up to 8 months. An increasing number of oligoclonal IgG bands during the course of the disease indicated expanding local intrathecal synthesis. Paraneoplastic etiology was ruled out by normal findings of extensive investigations for malignancy and negative paraneoplastic (Hu, Ri, Yo) and anti-glutamate acid decarboxylase (GAD) autoantibodies.