[Idiopathic hypersomnia of the central nervous system].

Idiopathic hypersomnia of the central nervous system is a cause of excessive diurnal somnolence which affects 5-10% of the patients who attend sleep clinics for this reason. We describe three male patients who consulted for excessive diurnal somnolence. Nocturnal polysomnographic studies followed by tests for multiple latencies of sleep were done. In all cases there was confirmation of lengthening of the time of nocturnal sleep with normal phases of sleep and an increase in the number of sleep spindles in phase II. Similarly there was an average latency of sleep of less than 10 minutes and fewer than two phases of REM in the multiple latencies test. All patients improved with drugs stimulating vigil, two of them with centramine and the third with methilphenidate. We consider the clinical data the polysomnographic criteria which help to establish the diagnosis.