2013-22: Anatomical and neurophysiological assessments of small nerve fiber function in patients with painful small fiber neuropathy and healthy controls.
The most common forms of painful peripheral neuropathies are caused by dysfunction or damage of small nerve fibres. Skin biopsy is currently the only procedure that allows direct quantification of small nerve fibre density and direct documentation of small nerve ending damage. However, intra-epidermal nerve fibre density (IENFD) assesses structure rather than function, is invasive and assessment of therapeutic efficacy in clinical trials requires repeat biopsy. This study will assess small fibre neuropathy with new, non-invasive methods including video thermography, corneal confocal microscopy (CCM), and the thermal grill illusion test. These methods will be compared to established tests; skin biopsy (gold standard), nerve conduction studies (NCS), and quantitative sensory testing (QST). We will investigate the relationships between pain, vasomotor response and nerve fibre loss in neuropathies of various aetiologies. This study is of the Centre for Human Drug Research, in collaboration of the R.O.I. for the ophthalmological assessments.