Prevalence (7 Dec 96)
Apparently none among the list subscribers had an answer to my two
queries aa few weeks ago, but a panel speaker at a recent symposium
had one, which I expand and record here for others as inquisitive as
I. For consistency I looked up rough estimates in Merck, even though
the articles are by different doctors with variable lucidity. They
may be out of date, since my edition of Merck is 1992:
The commonest neurological disorders affecting the elderly are:
1450; Cerebrovascular disease (including "stroke") is the most
common cause of neurologic disability in Western countries.
1437: Seizures, affecting 2% of total population; recurrent,
about 0.5%. Precise definition is rather complicated, and I
won't attempt it here.
1403: Dementia, including Alzheimer's, incapacitates over a million
Americans (public officials not specifically mentioned)
1495: PD is the 4th most common neurodegenerative disease of the
elderly. Affects about 1% of the population over 64 and 0.4%
(sic) of the population over 39.
Essential tremor, oddly, is not mentioned, but elsewhere I have seen
estimates that it may be 4-5 times as frequent as PD.
To my second question, why hyperexcitable blink reflex as a
"cardinal sign of PD" isn't more often used in diagnosis, I got only
a mumbled reply, indicating that the respondent perhaps didn't know.
Cheers, Joe
J. R. Bruman (818) 789-3694
3527 Cody Road
Sherman Oaks CA 91403
