Structure of nocturnal sleep in patients with cerebral insult

The aim of the present work was to study the structure of nocturnal sleep in patients who had sustained brain insults, and to relates sleep structure to the stage of disease and the location of the focal lesion. Studies were performed on 18 patients with ischemic insult, 8 affected in the right hemisphere, 6 affected in the left hemisphere, and 4 with brainstem lesions; controls consisted of 5 healthy subjects. Diagnoses were in all cases confirmed by computer tomography. Clinical and neurological studies were performed, along with recording of polygraph traces of nocturnal sleep (electroencephalograms, electrooculograms, electromyograms). Sleep parameters were analyzed using a program developed at the Sleep Studies Center, I. M. Sechenov Moscow Medical Academy; along with standard parameters, this program included analysis of the segmental structure of sleep. Sleep quality - the level of normality or disturbance to its structure - was assessed using a sleep index (SI). Patients showed profound disorganization of nocturnal sleep structure, with disruption of the mechanisms organizing sleep as a whole and generating and maintaining the individual stages. The greatest sleep disturbances were seen in ischemic insult in the right hemisphere and in patients with lesions in medial deep structures.