Brian,
I know that NCS’s are not good measures of small-fiber function whereas comparisons of distal/proximal IENFD’s by 3mm skin punch biopsies are accurate and reliable ways to assess small-fiber function. In the paper in my 1st post the authors noted that “only measures of small-fiber function improved in the 1st year of follow-up of IGTN” and concluded that the small fibers were particularly able to regenerate.

The authors noted that typical NCV studies of large myelinated fiber function were not reliable markers for IGTN (impaired glucose tolerance neuropathy). For example, the sural sensory response for sensory axonal function varied widely in their patient population and can have test reliability issues. Similarly, the peroneal motor conduction velocity for large myelinated motor fibers, while reproducible, is known to be relatively insensitive to reflect the small-fiber neuropathy characteristics of IGTN. Overall, the authors’ study did not show any statistically significant improvement in any NCS or QST test parameters for large-fiber function.

The authors also stated that their study was limited by the small number of patients and the lack of a placebo comparator group since all 40 patients were treated similarly but they were confident that their results were not due to a placebo affect since IENFD is a quantitative histologic measurement not subject to placebo – same rationale for their QSART results.

My own take on all this is that while after 1 year they couldn’t demonstrate a meaningful and measurable improvement in large fiber function, they could demonstrate meaningful and measurable improvements in small-fiber function and reinnervation including a reduction in pain.

Maybe future work w/ larger and more diverse patient populations together w/ placebo and blinded studies will demonstrate improvements in both large and small fiber function. In the interim your own regimen seems to have greatly improved all aspects of your PN which suggests to me that both small and large fibers could be affected in some way.

Hope this long post helps.

Alkymst