Re: Test for Sensory Neuropathy

Posted By mike on January 12, 1999 at 06:29:09:

In Reply to: Re: Test for Sensory Neuropathy posted by CCF Neurology W6 MD on January 12, 1999 at 06:18:56:







  I have been seeing a Neurologist for over 2 years for various problems. My latest has been Sensory Neuropathy.  Although not officially categorized as such, by the neurologist, from what I've read and of course feel, I'm there!. My feet burn constantly, walking on a cold floor feels good for my low voltage feet. All the tests have been done blood, tap, lyme, B, etc, etc. Only tap showed protein reading of 44.  The latest test has been EMG.My question is that she's indicated that a EMG does confirm Small Fiber Neuropathy? My Neurologist has tested the main sensory nerve that runs down the leg, but not the little nerves in the feet. From what I've read it sounds like it does not. When she tested my feet (which is where the problem is) the readings were 10.9 and 11. She indicated that 10 was abnormal so I'm not quite there yet. How do you determine when a person is to be classified as having sensory neuropathy? Also, from various web sites it sounds like the drug Mexitline (sp) is the most effective treatment for the "burning sensation" and that Neurotin is only somewhat effective. So with sunburn feeling feet that has been tested for just about every possible cause, I've classified myself as Idiopathic (sp) Polysensory Neuropathy... What are your thoughts? Also, I've noticed that my feet look wrinkly and red is this normal with this condition? And lastly, would a nerve biopsy help? Thank You...
  
Hi Mike,
EMG only checks for the large and fast fibers. A negative EMG with your symptoms DOES NOT rule out small fiber neuropathy which sounds like wwhat you have. There is a test called Quantitative Sensory Testing (QST) which unfortunately is not availble at many centers. This helps in some cases in making the diagnosis of small fiber neuropathy. Regarding the diagnosis of pure sensory neuropathy, we make this diagnosis if the EMG showed abnormal (low or absent) sensory responses from sensory nerves but normal motor responses from motor nerves, which is not the case with you (your sensory response is present and normal).
A nerve biopsy is helpful only in a handful of diseases and not routinely done. There is a new technique of skin punch biopsy being developed to look at small fiber neuropathy. We here at the clinic do QST and currently is developing a protocol for skin biopsy.
Good luck.