Disturbed hypothalamic-pituitary axis in idiopathic recurring hypersomnia syndrome.

Disturbed function of the hypothalamic-pituitary axis at adrenal and thyroid levels was found during an episode of hypersomnia in the idiopathic recurring hypersomnia syndrome. These endocrinological abnormalities, abolished ACTH and cortisol responses to insulin-induced hypoglycemia and absent TSH response to TRH, normalised thereafter in the symptom-free interval. These data support the hypothesis that Kleine-Levin syndrome is related to an intermittent hypothalamic dysfunction.