[Nocturnal sleep patterns during treatment of hydrocephalus].

By polygraphic methods the authors studied the sleep patterns during treatment of patients with subtentorial tumours causing hydrocephalus. Sleep recording was carried out in three stages of treatment: 1) before insertion of ventriculo-atrial valve, (7 investigations), 2) on the 7th day after valve insertion (7 investigations), 3) two months after removal of the posterior fossa tumour (3 investigations). The control group included patients with peripheral nerve injury in whom sleep recording was done before and after surgical treatment. In cases with hydrocephalus and raised CSF pressure before valve insertion the cyclic pattern of sleep was disintegrated, showing long periods of light sleep (phase 1 + 2) interrupted by long periods of alertness, during sleep, mostly with elimination of the remaining sleep components. The decrease of CSF pressure after valve implantation was parallelled by partial normalization of sleep pattern, that is shortening of the light sleep phase and reduction of the number of alertness during sleeping hours, as well as prolongation of the phases of deep sleep and appearance of paradoxical sleep. However, only removal of the tumour from the posterior fossa made possible approximation of sleep elements to those in the control group. Sleep disintegration of varying intensity in patients with hydrocephalus may be reversible, the rate of normalization of sleep depends on the intensity of sleep disturbances in the initial stage of the disease, but return to nearly normal sleep is possible only after removal of the subtentorial tumour.