Originally Posted by en bloc
Kind of odd that Johns Hopkins does not include the density enumeration on their skin biopsy results. I have had two skin biopsies at JH and both specify condition of the fibers (in great detail), but NO density percentages. So there is no way to determine in subsequent tests whether there is progression or improvement.
Originally Posted by glenntaj
--for skin biopsy results to show spotty damage, or incomplete damage, or damage in some places and not others.
A lot of it has to do with the interpretation of the tests. As I've written here before, many doctors rather lock-step accept the pathology reports that indicate definite evidence of small-fiber neuropathy only in accordance with the McArthur protocols originally developed at Johns Hopkins--interepidermal nerve fiber density below the fifth percentile or above the ninety-fifth percentile for age and location matched "normals". But since most people don't go in for an numeration of their small fibers when asymptomatic, it's hard to say what level of nerve fiber density they started at, and there is a wide range. For example, someone at around the fifteenth percentile may not be listed as having evidence of neuropathy, but if we had known years ago they were around the fiftieth percentile, to me that would be evidence of some process.
This is why it's good to get the records of the density enumeration, and why the specialized labs are also supposed to report the condition of the fibers observed under electron microscopy--abnormal branchings, swellings, evidence of inflammation, etc.
To go more in to my biopsies (I have had 3)...
First @ Umass Medical Center in Worcester w/ Dr. Novak, taken from R ankle and R upper thigh. Sample sites were frozen with a spray prior to being taken. Sample was sent to Therapath, NY. They did report the %'s, ankle was well within range (dont remember number) but thigh sould 55% reduction in nerve fibers (evident of SFN), neither sample noted any abnormalities though, i.e., swelling, etc.
Second @ Mass General as part of a clinical trial with Dr. Oaklander, only taken from left ankle, sample sites numbed with cream prior, again gave %'s, was well within normal with no abnormalities. They do not send te samples out, she counts them and analyzes them herself, said she has doen over 1000.
Third (done just a few weeks ago), @ Beth Israel w/ Dr. Freeman & Gibson, taken from Right ankle, low thigh and mid thigh, sample sites numbed with cream prior, gave %'s, all were well within normal limits w/o any swelling, branching, etc. Like MGH, they count and analyze themselves I believe.
Its just weird that in my previous biopsy from the same exact site, it should 55% damage and now it shows none (at any of the subsequent sites). Both Dr. Oaklander and Freeman/Gibson said that there is a high chance for artifact (assuming htis means fake damage) depeneding on how the sample is handled, what instrumentation is used, how it is sent out (if that is the case), what is used for anesthesia, among other possibilities, and that it is easy to get a false positive (which is why the test should be repeated to check on the sites)...
But from what I understand most neuro's (at least at the smaller hospitals where my 1st biopsy was done) dont like to repeat the testing, whether that be for insruance cost reasons, policy, or they dont see any real benefit from it.