An enuretic episode is most likely to occur 3 to 4 h after sleep onset, and usually, but not necessarily, in stages 3 and 4 sleep. It is preceded by a burst of rhythmic delta waves associated with a general body movement. If the patient is awakened at this point, he does not report any dreams. Imipramine (10 to 75 mg at bedtime) has proved to be an effective agent in reducing the frequency of enuresis. A series of training exercises designed to increase the functional bladder capacity and sphincter tone may also be helpful. Sometimes all that is required is to proscribe fluid intake for several hours prior to sleep and to awaken the patient and have him empty his bladder about 3 h after going to sleep. One interesting patient, an elderly physician with lifelong enuresis, reported that he had finally obtained relief (after all other measures had failed) by using a nasal spray of an analogue of antidiuretic hormone (desmopressin) at bedtime. This has now been adopted for the treatment of intractable cases. Diseases of the urinary tract, diabetes mellitus or diabetes insipidus, epilepsy, sleep apnea syndrome, sickle cell anemia, and spinal cord or cauda equina disease must be excluded as causes of symptomatic enuresis.
Relation of Sleep to Medical Illnesses
The high incidence of thrombotic stroke that is apparent upon awakening, a phenomenon well known to neurologists, has been studied epidemiologically by Palomaki and colleagues. These authors have summarized the evidence for an association between snoring, sleep apnea, and an increased risk for stroke. As already mentioned, cluster headache and migraine have an intricate relationship to sleep, the former almost always occurring during or soon after the first REM period, and the latter often curtailed by a sound sleep.
Patients with coronary arteriosclerosis may show electrocardiogram (ECG) changes during REM sleep, and nocturnal angina has been recorded at this time. Snoring is strongly associated with chronic hypertension. Asthmatics frequently have their attacks at night, but not concomitantly with any specific stage of sleep; they do have a decreased amount of stage N3 sleep and frequent awakenings, however. Patients with hypothyroidism have shown a decrease of stages N3 sleep, and a return to a normal pattern when they become euthyroid. Demented patients generally exhibit reduced amounts of REM and slow-wave sleep, as do children with Down syndrome, phenylketonuria, and other forms of brain damage. Alcohol, barbiturates, and other sedative-hypnotic drugs that suppress REM sleep produce extraordinary excesses of REM during withdrawal periods. This may, in part, account for the hyperactivity and confusion, and perhaps the hallucinosis, seen in withdrawal states.
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