“Sleep bruxism is a stereotyped movement disorder characterized by grinding or clenching of teeth during sleep.” This is a common disorder that is sometimes correlated with stress. It results in disrupted nocturnal sleep, temporomandibular joint dysfunction, damage to teeth, and morning headache. Bruxism is inhibited by the use of a nocturnal tooth guard.

“Sleep enuresis is characterized by recurrent involuntary micturition that occurs during sleep.” Bedwetting after the age of 5 years is considered abnormal. There may be a delay in toilet training without the development of continence during sleep, termed primary enuresis. Secondary enuresis refers to the development of bedwetting after toilet training is complete. Symptomatic enuresis is secondary to underlying medical disease - for example, urogenital disorder or nocturnal seizure. Some cases of enuresis follow arousal from delta sleep, but enuresis may occur in any sleep stage. If no underlying medical cause is identified, the disorder is treated with behavioral techniques that incorporate bladder capacity training and a wetness alarm. When behavioral techniques fail, medications may be used, including nocturnal nasal desmopressin (DDAVP) or imipramine.

“Nocturnal paroxysmal dystonia is characterized by repeated dystonia or dyskinetic (ballistic, choreo-athetoid) episodes that are stereotyped and occur during NREM sleep.” Both short- and long-lasting episodes have been described and appear to have different mechanisms. Short episodes often respond to carbamazepine, and there has been debate as to whether these episodes may represent seizure activity that is difficult to record with surface electrodes. Most evidence suggests that nocturnal paroxysmal dystonia of short duration represents nocturnal seizures of frontal lobe origin. Long-duration episodes have been observed in only a few patients; in one patient Huntington’s disease later developed.

“Sudden unexplained nocturnal death syndrome (SUND) is characterized by sudden death during sleep in healthy young adults, particularly of Southeast Asian descent.”