Leprosy
mailing list – April 10th, 2006
Ccn: all.
Ref.: Monofilaments for sensory testing.
From: Lehman
L., Brazil.
Dear
Salvatore,
I would like to respond to Dr. Hippke’s letter (LML
April 4th, 2006) about monofilaments for sensory testing.
1.
The nerve function (NF) exam needs to be kept simple in
decentralized programs and needs to be able to be done by auxiliary
staff, in addition to doctors, nurses and therapist. The biggest challenge is
getting the NF exam done routinely and this may mean we must consider
using 1 filament or a ballpoint pen and fewer sensory test sites. Additional filaments can be
added as health services develop their skills and knowledge.
2.
I agree that using colours are not good if you are
Xeroxing and/or do not have colour pencils or pens available. It is good to substitute with
either number or symbols. It
is important to follow up the process in supervision.
3.
2 grams does not mean that the hand and foot have NORMAL
sensation. It only means
they are not a WHO Grade 1 who are at higher risk of injury and should
be targeted for self-care training.
Many countries today still do not have a good or consistent
definition for the WHO grade 1. Examples
of countries who have defined WHO Grade 1 are Brazil in 1997 who
defined a 2 g loss as Grade 1. Nepal
defined Grade 1 as 2g loss for the hand and 10g loss for the foot,
Ethiopia 10g loss for both hands and feet.
4.
It is
important to realize that a WHO GRADE 0 actually can be experiencing
nerve function problems demonstrated by
a decrease in sensation and/or sometimes muscle weakness. They are in
need of treatment and careful monitoring so they do not progress to a
WHO Grade 1 or 2.
5.
If using monofilaments, I agree with Dr. Hippke’s
suggestion to start at 2g than either go lighter or heavier. It helps the testing go faster
but at times can be confusing to new learners.
6.
Referral centres should be expected to know how to use a
monofilament kit of 5-6 filaments, interpret the results, take
appropriate action and monitor the results or response to the
intervention (corticosteroids, surgery, activity restriction, etc). Referral centres also need to
work with their local health services to help them learn how to
identify Nerve Function Impairment (NFI) and treat it but also know
when to refer persons with NFI for more detailed testing and complex
interventions. CAUTION: Access and time required for
the person to go to a referral centre may be a problem which needs to
be addressed. I have
found it best to try and develop health services over time through
regular supervision to deal with NFI and other simple complications
locally and only refer those problems not responding to referral
centres.
7.
How
sensory loss is monitored varies worldwide. The ballpoint pen (many
countries), only the 2 g. filament, only the 10g filament, both the 2g
filament (hand) and 10g (foot) and the 5 or 6 filament kits. One must be clear what the
objective is for you sensory monitoring, early Nerve Function Loss
and/or Protective Sensory loss, both are important.
8.
In many countries, with the focus on “Elimination”,
nerve function testing has been frequently omitted within the clinical
exam and the importance of routine nerve function monitoring not
encouraged. Training and
supervision activities rarely include nerve function exam or simple
POD activities (serf-care training).
POD frequently has not been developed to be an integrated part
of HD control but treated separately causing health systems not to
have organized themselves to have a sustainable system to deal with
the complications associated with the disease after “elimination”.
9.
Now the challenge is to develop within the existing
health system, one which will and can deal with the complications
associated with HD when authorities have been lead to believe that
there are no more problems with the disease. Health services feel the
burden of the demand of resolving these complications with little to
no political and/or financial support.
Development of Monofilament:
·
The monofilaments that Dr. Hippke is referring to in his
letter is the Monofilament testing originating with
Semmes-Weinstein’s work in the USA done in 1960 in brain injury
which was based on von Frey’s horse hairs sensory testing. Later this was adapted by
Bell-Krotoski in her work at the Philadelphia Hand Rehabilitation
Center (1970’s) and the Gills W. Long Hansen’s Disease Research
Center in Carville, Louisiana (1980’s) to reduce the 20-monofilament
kit to 5 filaments. I
believe that the monofilament kit that Dr. Hippke is currently using
is the SORRI-BAURU kit which was developed in Brazil and includes
Bell-Krotoski’s 5 filaments plus the 10g filament (1990’s)
·
It
is important to note that Dr. Ben Naafs did important work in Addis
Ababa during the 1970’s with nylon filaments based on Waddell’s
modifications of the von Frey method noted in works done by Jamison,
1969 and Pearson et al, in 1971.
Naafs works demonstrated that monofilaments were a sensitive
method in following up of nerve involvement (ALERT 1977).
·
The GWLHDC was doing research (1990) and acquired funds
to request the production of a large quantity of filament material
which included the 10g that was distributed worldwide (Brazil, India,
Nepal, etc).
·
Bell-Krotoski found that a visual interpretation was made
quicker by using a color code versus a number. She defined the colors
currently used green, blue, purple, red and black for no response. The doctors and therapist
found that it facilitated monitoring changes quickly.
·
At GWLHD in Carville Louisiana, Bell-Krotoski’s work in
the 70’s and 80’s focused on the early detection of nerve
impairment where as Birke’s focus (1986) was on Protective sensory
loss of the foot that puts the person at higher risk of plantar
ulceration.
·
Lehman combined the two adding the 10g to Bell-Krotoski’s
5-filament kit, later helping to develop the SORRI BAURU model used on
both the hands and feet.
·
The Brazilian national POD technical advisory team
working with the national HD coordination (Dr. Maria Leide Wand del
Rey de Oliveira) and the ILEP national project in 1997, made
recommendations for simplification of sensory testing for the
decentralization process of HD control to health centers throughout
Brazil. A consensus was
based on operational factors, both Bell-Krotoski’ and Birkes work in
addition to Brazilian hand and foot data collection. The WHO Grade 1 was DEFINED as
not feeling 2grams with the monofilament or not feeling the light
touch/pressure of a ballpoint pen.
Ideally the group wanted a 2g for the hand and 10g for the foot
but it was rejected as to difficult for implementation in a large
decentralized situation to all parts of Brazil. The objective was to choose 1
filament which would detect a nerve problem in both and hands and feet
but not wait till a 10g sensory loss level was reached. Brazilian data showed all
normal feet and hands felt 2grams and so if a person did not feel the
2 grams they were known to have a problem.
·
Van
Brakel, et al did extensive work and studies with the monofilaments
for NFI starting in the 1990’s to present.
Some References:
Becx-Bleumink
M, Berhe D. Occurrence of reactions, their diagnosis and management in
leprosy patients treated with multidrug therapy; experience in the
leprosy control program of the All Africa Leprosy and Rehabilitation
Training Center (ALERT) in Ethiopia. Int J Lepr, 1992; 60: 173-184.
Bell JA
Sensibility evaluation. In Hunter J, et al,
editors, Rehabilitation
of the hand, St.
Louis 1978, Moby.
Bell Krotoski, J “Pocket
filaments and specifications for the Semmes-Weinstein monofilaments,
J. Hand Therapy 3:1 26, 1993.
Birke JA, Sims DS. Plantar sensory threshold in the
ulcerative foot. Lepr.
Rev 57: 261-267, 1986
Croft
RP, Richardus JH, Nicholls PG, and Smith WC. Nerve function
impairment in leprosy: design, methodology and intake status of a
prospective cohort study of 2664 new leprosy cases in Bangladesh (The
Bangladesh Acute Nerve Damage Study). Lepr Rev, 1999; 70: 140-159
Kets CM, van
Leerdam ME, van Brakel WH, Deville W, Bertelsmann FW. Reference values for touch
sensibility thresholds in healthy Nepalese volunteers. Lepr Rev, 1996; 67: 28-38.
Lehman, LF et al. The development of the
Semmes-Weinstein Monofilaments in Brazil, J. of Hand Therapy
6:290, 1993.
Naafs
B and Dagno T. Sensory Testing: A sensitive method in the
follow up of Nerve Involvement.
International Journal of Leprosy 1977; 45: 364-368.
Naafs
B, Pearson JM, Wheate HW. Reversal
reaction: the prevention of permanent nerve damage. Comparison of
short and long-term steroid treatment. Int J Lepr, 1979; 47: 7-12.
Richardus
JH, Finlay KM, Croft RP, Smith WC. Nerve function impairment in
leprosy at diagnosis and at completion of MDT: a retrospective cohort
study of 786 patients in Bangladesh. Lepr Rev, 1996; 67: 297-305.
Semmes J, et al. Somatosensory changes after
penetrating brain wounds in ma, Cambridge, Mass, 1990, Harvard
University Press.
Saunderson
PR, Gebre S, Desta K, Byass P, Lockwood DN. The pattern of leprosy-related
neuropathy in the AMFES patients in Ethiopia: definitions, incidence,
risk factors and outcome. Lepr Rev, 2000; 71: 285-308.
Semmes
J. Fifty years of
somatosensory research from the Semmes Weinstein monofilaments to the
Weinstein enhanced sensory test, Journal of
Hand Therapy 6:1, 11, 1993.
van
Brakel WH, Reed NK, and Reed DS. Grading impairment in leprosy. Lepr Rev, 1999; 70: 180-188.
van
Brakel WH, Shute J, Dixon JA, Arzet H. Evaluation of sensibility in
leprosy--comparison of various clinical methods. Lepr Rev, 1994; 65: 106-121.
Linda
F. Lehman, OTR MPH C. Ped
Regional
Prevention of Impairment and Disability Consultant (Americas &
Africa)
American Leprosy Missions WEB: www.leprosy.org
Tel/Fax
Brazil 55-(0)31-3476-6842 or cell 55-(0)31 9637-5576
lehman@uai.com.br
