Leprosy
mailing list – May 11th, 2005
Ccn: all.
Ref.: sensory testing.
From: R S Jerskey, Los Angeles and
San Diego, California, USA.
Dear Dr. Noto,
Cordial greetings. Would you kindly include the following letter
to the group mailings?
Thanking you in advance,
Robert S.
Jerskey, LOTR, prevention of impairment and disability consultant,
National Hansen's Disease Program,
Los Angeles
and
San Diego
,
California
,
USA
I would like to respond to Dr. P Narasimha Rao (LML May 4th, 2005)
and his stimulating letter re.: methods of sensory testing -
specifically regarding the use of pins and needles, solid or bored vs.
the use of ball point pens.
I would be rather chary to utilize such sharp tools, though
inexpensive, for testing light touch sensation on the extremities, on
the trunk, and, particularly, on the face. Application is not
apt to be reproducible, whether it be by the same tester or via
multiple testers. Indeed, the compression stress and pressure,
as defined as force per unit area, of a pin or needle to the target
site has the potential of being alarmingly high. I would think
that the sharpness of their tip geometry vis a vis the ball point pen
would likely result in more "false negatives" than even the
pen.
Further, there is ample literature, whether based on studies in the
Indian subcontinent, Brazil, the USA and other areas of the world that
the Semmes-Weinstein nylon filaments are of much utility to measure
and monitor tactile touch-pressure thresholds, including light touch.
Besides their known acceptable reproducibility, they are graded such
that even the touch-pressure sensibility of suspect lesions on the
face might be measured and monitored.
There is
little data on normative tactile touch-pressure thresholds of the
face, and I believe there is need for further investigation in that
area. Meanwhile, I refer interested readers to the Int J Lepr
Other Mycobact Dis. 1998 Sep;66(3):348-55. There is an article on
Quantitative assessment of facial sensation in leprosy by Premkumar R,
Daniel E, Suneetha S, Yovan P. which concludes that the
0.05 gram
filament (index number 2.83) would be appropriate. I think it
would be very difficult to apply such a light force of
0.05 grams
with a needle or pen. In fact, there are other graded,
light filaments in the complete 20 filament kit that were not used in
this study, one of which might yield even more favourable results for
the face, but which are not very accessible in the global landscape,
whereas the 2.83 filament is.
I believe it
would be well worth further exploring and exploiting the use of the
nylon filaments on suspect lesions of the face as well as other areas
of the body in order to optimize new case detection assessments.
Warm regards,
Robert Jerskey, LOTR
rjerskey@lacusc.org
robjerskey@yahoo.com
