Need For Specific 10 Gram Semmes-Weinstein /Frey Mono-filaments For Diabetic Peripheral Neuropathy Testing Unnecessary

Not wanting to waste money buying expensive monofilaments, I bought a scale and fishline – and now since I have come across a certain article, I realize any 1 cm medium to thick plastic monofilament fishline will do.

Well I started testing monofilaments, I found you had to get to 1 cm length to start getting over 1 gram pressure and a fairly thick monofilament to get over 10 grams. However, almost any moderate thickness monofilament fishlline will give you over 1 gram. Now I find I have re-invented the wheel as others have already found that out and found that 1 Gram monofilament is actually a better tester that the standard 10 gram anyway. So long as you get a line somewhere between 1-10 grams – it’s fine.

Diabetic peripheral neuropathy: how reliable is a homemade 1-g monofilament for  screening? A case-control study of sensitivity, specificity, and comparison with  standardized sensory modalities
Journal of Family Practice, June, 2006 55(5) 505-508
by Matthew E. Bourcier, Jagdeesh Ullal, Henri K. Parson, Charlotte B. Dublin, Crystal A.G. Witherspoon, Sheila A. Ward, Aaron I. Vinik 
http://www.jfponline.com/home/article/diabetic-peripheral-neuropathy-how-reliable-is-a-homemade-1-g-monofilament-for-screening/3fd46fd2b21226960e21a02859a5599b.html

or here:
frey

They found in DM peripheral neuropathy,

1 gm had a  sensitivity of  52.4% (not feeling it could pick out about half of cases)  and specificity of  96.3% (if you couldn’t feel it, it meant most likely there was a problem)
10 gram had a sensitivity of 42.8% (less!) and specificity of 99.2%

What this means is that there is very little difference between 1 -10 Gram monofilaments for testing. Any moderate or more fishline will give you over 1 Gram so pick a moderately thick fishline, cut a 2 cm length, tape over first cm, and use the end for testing. Make as many as you will want easily – give them to diabetics to test themselves, and don’t waste your money on bought monofilaments.

Any comments?

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2 Responses to Need For Specific 10 Gram Semmes-Weinstein /Frey Mono-filaments For Diabetic Peripheral Neuropathy Testing Unnecessary

  1. Tony Nicholl says:

    if any moderate fish line would do; why do you think Bourcier and chums insist that you should
    “Be sure to measure and confirm the buckling force of homemade filaments”? (fast track) ?

  2. Marcelo Victor Pires de Sousa says:

    I am a physicist working on light neuron interaction to decrease pain. In order to conduct my research on low level lase light therapy to decrease pain I developed the von Frey filaments which I showed in the paper (http://www.sciencedirect.com/science/article/pii/S0165027014001332).

    My comment about the use of fishing line is: there are other types of filaments that can produce better results (more precision and accuracy) but as you told many times it is not necessary and the low-cost and easy availability many times is more important.
    Higher force can be achieved using fibers wires like: optical fibers or glass fiber, they are flexible but bend in a higher force.

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