[Changes in sleep pattern in presenile and senile dementia (author's transl)]

Analysis of polygraphic recordings of nocturnal sleep in 21 patients with "degenerative" dementia led to the identification of two types of tracing. The first type was characterised by morphologically normal sleep with more marked quantitative changes than those caused by simple aging. In the second type, the criteria of identification of the physiological stages of sleep disappeared, requiring special definition of the E.E.G. appearances seen. These two types corresponded to two different stages of advancement and probably were indicative of the progressive extension of lesions.