This state, as remarked earlier, has been induced in animals by lesions in the tegmentum (median raphe nuclei) of the pons. Comparable states are known to occur in humans but are rare. Asomnia in hospital practice is a result of delirium of any type, including delirium tremens and drug-withdrawal states. Drug-induced psychoses and mania may induce a similar state. We have seen a number of patients with a delirious hyperalertness lasting a week or more after temporofrontal cerebral contusions or in association with a hypothalamic lymphoma. None of the various treatments we have tried has been successful in suppressing this state. It was transitory in the traumatic cases.
Several paresthetic disturbances, sometimes distressing in nature, may arise during sleep. Everyone is familiar with the phenomenon of an arm or leg “falling asleep.” Immobility of the limbs and maintenance of uncomfortable postures, without any awareness of them, permit undue pressure to be applied on peripheral nerves (especially the ulnar, radial, and peroneal). Pressure of the nerve against the underlying bone may interfere with intraneural function in the compressed segment of nerve. Sustained pressure may result in a sensory and motor paralysis—sometimes referred to as sleep or pressure palsy. Usually, this condition lasts only a few hours or days, but if compression is prolonged recovery may be delayed. Deep sleep or a stupor, as in alcohol intoxication or anesthesia, renders patients especially liable to pressure palsies merely because they are not able to heed the discomfort of a sustained unnatural posture.
Acroparesthesias are frequent in adult women and are not unknown in men. The patient, after being asleep for a few hours, is awakened by numbness or a tingling, prickling, “pins-and-needles” feeling in the fingers, and hands. There are also aching, burning pains or tightness, and other unpleasant sensations. With vigorous rubbing or shaking of the hands or extension of the wrists, the paresthesia subsides within a few minutes, only to return later or upon first awakening in the morning. At first, there is a suspicion of having slept on an arm, but the frequent bilaterality of the symptoms and their occurrence regardless of the position of the arms dispels this notion. Usually the paresthesia is in the distribution of the median nerves, and almost invariably proves to be caused by carpal tunnel syndrome.
Nocturnal grinding of the teeth, sometimes diurnal as well, occurs at all ages and may be as distressing to the bystander as it is to the patient. It may also cause serious dental problems unless the teeth are protected in some way. There are many hypothetical explanations, all without proof. Stress is most often blamed, and claimants point to EMG studies that show the masseter and temporalis muscles to be excessively contracted. When present in the daytime, it may also represent a fragment of segmental dystonia or tardive dyskinesia.
Nocturnal Enuresis (See Also Chap. 25)
Nocturnal bedwetting with daytime continence is a frequent disorder during childhood, which may persist into adult life. Approximately 1 of 10 children 4 to 14 years of age is affected, boys more frequently than girls (in a ratio of 4:3); even among adults (military recruits), the incidence is 1 to 3 percent. The incidence is much higher if one or both parents were enuretic. Although the condition was formerly thought to be psychogenic, the studies of Gastaut and Broughton revealed a peculiarity of bladder physiology. The intravesicular pressure periodically rises to much higher levels in the enuretic than in normal persons, and the functional bladder capacity of the enuretic is smaller than normal. This suggests a maturational failure of certain modulating nervous influences.