I have been living with what I thought was idiopathic small fiber sensory neuropathy for the past 12 years.

Decided to go to Johns Hopkins for an evaulation. Results came back as follows:

Normal or negative results for Lyme, TTG, SSa, SSb, endomysial antibody, SPEP, lg quants, TSH (0.57) and SIFE.

Skin biopsy - 25029 distal thigh - right, epidermal nerve fiber density at low
range of normal at approx. 8 fibers/mm
25030 prox thigh - right, epidermal nerve fiber density and
appearance are within a normal range
25028 distal leg - right, epidermal nerve fiber density is reduced
at 2-3 fibers/mm

The three biopsies demonstrate a length-dependent neuropathic process affecting small caliber sensory nerve fibers.

My B6 is elevated at 117 ng/mL where normal is 2.1 - 21.7

Based on the above results the doctor said I had mild small fiber neuropathy. And the tests suggest the cause is the elevated B6. I also had a glucose tolerance test back in 2005 that showed impaired fasting glucose at 108. However, my yearly glucose since then has always been < 100.

The mylegram of my spine that I took with me to JH also shows evidence of lumbar polyradiculopathy. I knew this because I have been seeing a neurosurgeon who is fairly certain that the stenosis is so bad in my lumbar that it is contributing to the PN! In fact, I have scheduled surgery later this month.

My suggestion from JH is to stop my daily B6 supplement of 25 mg sublingual,
treat the lumbar problem conservatively for now, diet and exercise.

Has anyone heard of other cases where the SFN is caused solely by elevated B6? I have been taking the supplement for the past 5-6 yrs along with a multi-vit which also has 18 mg of B6 (as pyridoxine hydrochloride).

I sure would like to hear any feedback you could provide as now I am somewhat torn about the upcoming back surgery. Thanks so much.