Saturday, November 12, 2005

Neurology in an aging population

BrooklynDodger, getting on in years, spends time day to day joking with colleagues about losing mental edge, forgetting stuff, etc. Whistling in the dark. Maybe this posting isn't funny, but the Dodger started it and doesn't have the energy to find another paper.

Parkinson's is of some current interest to OH practitioners because of the apparent association with welding, and possibly prevailing exposures to manganese.

Parkinson's would not appear to have any aspect of cognitive causality, or projection on cognitive function. Nevertheless, whatever is causing the peripheral signs may also be causing problems with central functioning.

Disappointing on reading the full text is absence of the diagnostic questions which define "Excessive Daytime Sleeping" in this very old group of men, who average 77+ years. Feeling sleepy most of the day was the most the investigators would give us. EDS was found in about 8% of this population; the EDS group was more depressed, napped longer (not significant) and got up more at night. Plausibly the underlying process leading to presentation of Parkinson's signs is also causing sleep disturbances? Or maybe depressive processes which cause sleep disturbances?

Parkinson's incidence observed was 0.2 per 100 person years, elevated 3 fold among persons with EDS at entry.

NEUROLOGY 2005;65:1442-1446

Excessive daytime sleepiness and subsequent development of Parkinson disease

R. D. Abbott, PhD, G. W. Ross, MD, L. R. White, MD, C. M. Tanner, MD, PhD, K. H. Masaki, MD, J. S. Nelson, MD, J. D. Curb, MD and H. Petrovitch, MD

From the Division of Biostatistics and Epidemiology (Dr. Abbott), University of Virginia School of Medicine, Charlottesville, VA; the Pacific Health Research Institute (Drs. Abbott, Ross, White, Masaki, Nelson, Curb, and Petrovich), the Department of Veterans' Affairs (Drs. Ross, White, and Petrovich), the Honolulu-Asia Aging Study, Kuakini Medical Center (Drs. Abbott, Ross, White, Masaki, Curb, and Petrovich), the Department of Geriatric Medicine (Drs. Abbott, Ross, Masaki, Curb, and Petrovich), the Department of Medicine (Drs. Ross, Curb, and Petrovich), and the Department of Pathology (Dr. Nelson), John A. Burns School of Medicine, University of Hawaii, Honolulu, HI; and the Parkinson's Institute (Dr. Tanner), Sunnyvale, CA.

Objective: To determine if excessive daytime sleepiness (EDS) can predate future Parkinson disease (PD).

Methods: EDS was assessed in 3,078 men aged 71 to 93 years in the Honolulu-Asia Aging Study from 1991 to 1993. All were free of prevalent PD and dementia. Follow-up for incident PD was based on three repeat neurologic assessments from 1994 to 2001.

Results: During the course of follow-up, 43 men developed PD (19.9/10,000 person-years). After age adjustment, there was more than a threefold excess in the risk of PD in men with EDS vs men without EDS (55.3 vs 17.0/10,000 person-years; odds ratio [OR] = 3.3; 95% CI = 1.4 to 7.0; p = 0.004). Additional adjustment for insomnia, cognitive function, depressed mood, midlife cigarette smoking and coffee drinking, and other factors failed to alter the association between EDS and PD (OR = 2.8; 95% CI = 1.1 to 6.4; p = 0.014). Other sleep related features such as insomnia, daytime napping, early morning grogginess, and frequent nocturnal awakening showed little relation with the risk of PD.
Conclusions: Excessive daytime sleepiness may be associated with an increased risk of developing Parkinson disease.

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