Timely Neuropathy Testing
WHAT DO THE LEVELS MEAN?
Monofilament Sizes Included in the
Screen
and Monitoring Sets
1) The 2.83 [within normal limits 50 milligram level*] found in studies to be
"within normal limits" for the
hand, dorsum of foot and rest of body.
2) The 3.61 [diminished light touch 200 milligram level*]
found in studies to be
"within
normal limits" for the plantar foot.
[The level of
detection for
normal subjects on the plantar surface of the foot was
originally established by Weinstein, co-inventer and original author of the nylon
monofilament test,
to be at the 200 milligrams level (several orders of magnitude
lighter than 10
grams, and even lighter than 1 gram.). This
200 milligram normal
threshold level for the plantar surface of the foot
has been confirmed more recently
by multicenter studies. The foot plantar surface (sole) instep,
underneath toes, and
even entire surface for some individuals is at the 2.83 50
milligram level. This is
useful information for those assessing the exact status of a particular nerve. In
non- shoe wearing populations, a degree
of callus can mask normal threshold
detection, and the instep and underneath toe
area can help define the actual nerve
status. Foot screen monitoring sites are usually only on the
contact area of he foot.]
3) The 4.31 [diminished protective sensation 2 gram level*]
"protective"
monofilament to identify diminished but still
present protective sensation any place on
the body,
4) The 4.56 [loss of protective sensation 4 gram level*] monofilament to
identify
"loss of protective sensation" on the hand and rest of
the body including the dorsum
of the foot.
5) The 5.07 [protective sensation for plantar foot 10
gram level*] monofilament
commonly used to identify protective or
loss of protective sensation in
patients are at
risk of ulcers and amputations on the plantar surface of the foot
where there is often
more callus.
6) The 6.65 "residual deep pressure" monofilament
to identify when a nerve
has lost useful nerve sensory function. This monofilament is also used to identify a
patient who after
nerve loss or repair
first responds and indicates some return in
nerve function
before lighter monofilaments are detected.
and monitoring of neuropathy (worsening or improvement of sensibility) studies
need to include normal threshold monofilaments for hands and feet.]
program, the threshold for "
loss of protection" on the foot was determined to be
and rest of the body. Earlier
detection of those at risk can possibly result in
improved
treatment and protection
for the nerve before there is permanent and irreversible
damage. Still the 10
gram
level monofilament has become widely accepted and is
a useful aide in
having
patients actually inspect their feet, and recognize a severe loss
of protective
sensation where they are at risk of ulcers and amputations.]
is the closest filament to 10 grams in the original set of 20 monofilaments. This is
the monofilament size used in foot program studies at the
National Hansen's
Disease Center, Carville, LA. Its force was simply rounded to be understood
for professional and untrained
health care workers who were taught foot screens.
Those who adjust or cut off this standard size monofilament to achieve an
exact
10 gram force of application then run the risk of producing a heavier monofilament
than was used in the studies
that originally defined this force. Some even consider
even the 5.07 monofilament to be too heavy for detection of
"loss of protective
sensation "
on the
plantar surface of the foot. It is also important to identify
patients with
earlier more responsive to direct treatment for the nerve condition
as well as those patients with blisters and
ulcers.]