Driving safety among older adults.

Circadian Rhythm Disorders: Advanced Phase Sleep Disorder The tendency for elderly patients to spend more time asleep during the day and less time asleep at night raises the possibility that neurological dysfunction of the biologic clock within the suprachiasmatic nucleus of the hypothalamus mediates these changes. Advanced phase sleep disorder is a well-recognized circadian disorder in which patients complain of difficulty staying awake in the evening and early morning awakening. This disorder is common in the elderly and may be mistaken for early morning insomnia. Phase advance is exacerbated by visual impairment and low light exposure during the da ; evening light exposure can therapeutically delay rhythms and improve sleep maintenance. REFERENCES 1. The AASM manual for the scoring of sleep and associated events. Westchester, IL: American Academy of Sleep Medicine, 2007. 2. Medicare National Coverage Determinations Manual Chapter 1, Part 4 Section 240.4. http:// www.cms.hhs.gov/manuals/downloads/ ncd103c1_Part4.pdf 3. Kryger MH, Roth T, Dement WC. Principles and Practice of Sleep Medicine. 4th ed. Philadelphia, PA: Elsevier/Saunders, 2005. 4. The international classification of sleep disorders : Diagnostic & coding manual, ICSD-2. 2nd ed. Westchester, IL: American Academy of Sleep Medicine, 2005. 5. Allen RP, Picchietti D, et al. Restless legs syndrome: Diagnostic criteria, special considerations, and epidemiology. A report from the restless legs syndrome diagnosis and epidemiology workshop at the National Institutes of Health. Sleep Med 2003;4(2):101-119. 6. Silber MH, Ehrenberg BL, et al. An algorithm for the management of restless legs syndrome. Mayo Clin Proc 2004;79:916-22. 7. Boeve BF, Silber MH, et al. Pathophysiology of REM sleep behaviour disorder and relevance to neurodegenerative disease. Brain 2007. 8. Campbell SS, Dawson D, Anderson MW. Alleviation of sleep maintenance insomnia with timed exposure to bright light. J Am Geriatr Soc 1993;41:829-36. Jean K. Matheson, MD, is Sleep Disorders Center, Beth Israel Deaconess Medical Center, and Associate Professor of Neurology, Harvard Medical School.