Nocturnal psychophysiological correlates of somatic conditions and sleep disorders.

Modern sleep research studies have provided the practicing physician with considerable new information concerning the basic psychophysiology of sleep, the effects of medical conditions on sleep and the role of maturational and emotional factors in producing certain sleep disorders. Medical and psychiatric disorders, sleep disorders and drug-induced sleep stage alterations are studied in the sleep laboratory using the same techniques developed to analyze sleep patterns in normal subjects. After initial sleep laboratory adaptation, a profile of the sleep characteristics of various clinical conditions is obtained. This profile can be compared to sleep profiles of normal subjects as well as to the effects on sleep of subsequent experimental or therapeutic procedures. Various studies have shown that coronary artery, duodenal ulcer and nocturnal headache patients experience angina, increased gastric acid secretion and migraine or cluster headaches, respectively during REM sleep. Adult nocturnal asthamtic episodes occur out of all sleep stages while attacks of dyspnea in asthmatic children occur in all stages except stage 4 sleep. Hypothyroid patients show decreases in stages 3 and 4 sleep, while in hyperthyroid patients the percentage of time spent in stages 3 and 4 sleep is markedly increased. Enuretic episodes occur predominantly in non-rapid eye movement (NREM) sleep. Sleepwalking and night terror episodes occur exclusively out of NREM sleep, particularly from stages 3 and 4 sleep. Most child somnambulists and children with night terrors "outgrow" this disorder, suggesting a delayed maturation of the central nervous system. Stimulant drugs are effective in the treatment of the sleep attacks of narcolepsy and in treating certain cases of hypersomnia, while imipramine is an effective treatment for the auxillary symptoms of narcolepsy. Psychological disturbances are frequent in adult somnambulism and night terrors as well as in hypersomnia and insomnia. Proper pharmacologic treatment to provide symptomatic relief for insomnia is recommended to enhance the psychotherapeutic process.