[Sleep in neurologic diseases]

Neurological diseases may induce alterations in sleep which are difficult to interpret owing to the multiple interferences introduced by treatments, associated somatic symptoms and time-related changes in causal lesions. The consequences of vascular or traumatic lesions observed in man confirm the data obtained from experimental lesions created in animals, thereby throwing some light on the roles played by the cerebral cortex, the thalamus and the brain stem nuclei. In degenerative diseases polygraphic recordings show subclinical signs of extension which are exceptionally specific of any particular type of degeneration. In epileptic patients recordings have determined the distribution of intercritical activities in the various waking and sleep stages: an increase of the activities during sleep appears to be a fairly independent constitutional feature. To sum up, one may say that the various sleep and waking control systems may be diversely affected by diseases of the nervous system. States of vigilance modulate some critical pathologies, such as epilepsy, according to modalities and a physiopathology that have not yet been fully elucidated.