[A case of recurrent hypersomnia with excellent response to lithium carbonate].

We report a 38-year-old woman with recurrent hypersomnia, in whom lithium carbonate was effective in preventing hypersomnia attacks. After onset at 26 years, she complained of frequent and severe episodes of hypersomnia accompanied by anorexia and urinary incontinence. Electroencephalogram showed mild slowing during a hypersomnic period, but not during an asymptomatic period. The CSF orexin level was normal during a hypersomnic period. The effectiveness of lithium was confirmed because the symptoms recurred after its withdrawal and disappeared after its reintroduction. The treatment of recurrent hypersomnia has not been established although the effectiveness of lithium has been described in some cases. This report supports the importance of maintaining effective serum lithium levels in the treatment of recurrent hypersomnia.