Insomnia Associated with Neurologic Disorders A variety of neurologic diseases result in sleep disruption through both indirect, nonspecific mechanisms (., pain in cervical spondylosis or low back pain) or by impairment of central neural structures involved in the generation and control of sleep itself. For example, dementia from any cause has long been associated with disturbances in the timing of the sleep-wake cycle, often characterized by nocturnal wandering and an exacerbation of symptomatology at night (so-called sundowning). Epilepsy may rarely present as a sleep complaint (Chap. 363). Often the history is of abnormal behavior, at times with convulsive movements during sleep | Chapter 028. Sleep Disorders Part 8 Insomnia Associated with Neurologic Disorders A variety of neurologic diseases result in sleep disruption through both indirect nonspecific mechanisms . pain in cervical spondylosis or low back pain or by impairment of central neural structures involved in the generation and control of sleep itself. For example dementia from any cause has long been associated with disturbances in the timing of the sleep-wake cycle often characterized by nocturnal wandering and an exacerbation of symptomatology at night so-called sundowning . Epilepsy may rarely present as a sleep complaint Chap. 363 . Often the history is of abnormal behavior at times with convulsive movements during sleep. The differential diagnosis includes REM sleep behavior disorder sleep apnea syndrome and periodic movements of sleep see above . Diagnosis requires nocturnal polysomnography with a full EEG montage. Other neurologic diseases associated with abnormal movements such as Parkinson s disease hemiballismus Huntington s chorea and Tourette syndrome Chap. 366 are also associated with disrupted sleep presumably through secondary mechanisms. However the abnormal movements themselves are greatly reduced during sleep. Headache syndromes migraine or cluster headache may show sleep-associated exacerbations Chap. 15 by unknown mechanisms. Fatal familial insomnia is a rare hereditary disorder caused by degeneration of anterior and dorsomedial nuclei of the thalamus. Insomnia is a prominent early symptom. Patients develop progressive autonomic dysfunction followed by dysarthria myoclonus coma and death. The pathogenesis is a mutation in the prion gene Chap. 378 . Insomnia Associated with Other Medical Disorders A number of medical conditions are associated with disruptions of sleep. The association is frequently nonspecific . sleep disruption due to chronic pain from rheumatologic disorders. Attention to this association is important in that sleep-associated symptoms are
