Periodic somnolence was described by Kleine1 in 1925, but the pathophysiology of this illness is uncertain. Treatment with certain stimulants, such as methylphenidate hydrochloride, is only symptomatic without prophylactic effect.
We recently treated a case of periodic somnolence in which methylphenidate was ineffective, but administration of lithium carbonate gave symptomatic and prophylactic improvement.
Report of a Case.—
A 17-year-old male student caught a "cold" Nov 2, 1972. One week later, he left school and slept for most of the next week, only rising to evacuate or eat.The patient became ambulant Nov 15. On Nov 16, he was restless, talkative, and experienced insomnia. On Nov 18, those symptoms disappeared and the patient returned to his normal condition. Four subsequent episodes of somnolence have occurred at intervals between 23 and 30 days; another episode took place on Dec 13, and he was hospitalized on Dec 16.Several factors precipitated episodes