We devised a new generation, highly sensitivity method to diagnosis peripheral neuropathy early, when the probability for reversal is greatest. Cancer chemotherapy and diabetes are the most common causes of neuropathy in the USA. Both cause decreased sweating, abnormal circulation, peripheral numbness, pain and weakness. If diagnosed early, both are potentially treatable. Unfortunately, the minimal changes in function, that first signal impending neuropathy or response to treatment, escape detection by current tests. Early recognition would provide a better opportunity to treat, halt or reverse neuropathy than later discovery after significant nerve degeneration. Our sensitive sweat test (SST) detects early dysfunction of sudomotor nerves that activate sweat glands (SGs) by measuring the rate and volume of water secreted from each of >200 individual SGs per image. The innovative feature of the SST was placement of starch-coated Scotch(R) tape on the iodine-coated skin. Tape forces the sweat droplets to flow centrifugally in a flat expanding spot made densely black by reaction of the sweat-wetted starch and iodine. The rate of expansion of the black spot is proportional to the sweat rate of that SG. Spot area is proportional to volume from the same SG. The sweat spots are imaged by miniature device at 1 image/sec for 90 seconds, counted and rates and volumes calculated. Each SG appears to have its own characteristic secretion rate. Dysfunction of secretion at the level of the single gland is an earler indicator of beginning neuropathy than the current QSART measure of total water/skin area. The SST appears capable of measuring progression of neuropathy and potential to record degrees of recovery by recording small incremental changes of sweat rate and volume from single SGs. The SST can make diagnosis and evaluation of neuropathy faster, more convenient and less expensive. Phase I has been highly successful. We constructed a compact, computer mouse size, sensitive device that we used to test controls and patients with diabetic and chemotherapy neuropathy. Sweat spot counts, their distribution, and individual SG rate and volume of water secreted correlated with severe neuropathy on the foot and calf. In Phase II we will construct a market-ready device that is convenient, affordable, hand held and easily used in medical clinics, at the bedside or in the home. We will obtain control values from large numbers of healthy persons and test patients with CIPN, diabetic neuropathy and other neuropathies in MN and from three collaborating institutions. Commercialization will be in partnership with the WR Co Inc. a MN medical device company that markets other medical devices.
Neuro Devices will manufacture, test and market a miniature highly sensitive sweat test (SST) device to measure rate and nano liter volumes of sweat secreted by >200 single sweat glands for earlier diagnosis and detection of progression or recovery with treatment, of patients with chemotherapy-induced, diabetic and other neuropathies.
| Provitera, V; Nolano, M; Caporaso, G et al. (2010) Evaluation of sudomotor function in diabetes using the dynamic sweat test. Neurology 74:50-6 |
