Neuro Devices, Inc. will construct a dynamic sweat test (DST) for early detection of peripheral neuropathy. Neuropathy is detected by measuring the rate and volume of sweat secreted by single sweat glands (SGs) under the control of sudomotor nerves. The test has a major advantage over other tests of nerve function because SGs are accessible for analysis on distal sites of the hands and feet where the first signs of neuropathy appear. Device feasibility will be tested by comparing results from testing healthy control subjects and cancer patients with chemotherapy induced peripheral neuropathy (CIPN). Physicians at the M.D. Anderson hospital, Houston will add the DST to their extensive sensory testing of patients during chemotherapy that they perform to detect the initial signs of neuropathy. Early detection is beneficial because the potential for recovery declines with progressive nerve degeneration. Early diagnosis also provides the opportunity to decide if the chemotherapeutic agent should be decreased in dosage, discontinued, substituted or, when no neuropathy is detected, if chemotherapy can be increased to more effective cancer killing dosage. Existing sensory tests lack this sensitivity for early detection of minimal nerve abnormality. The dynamic sweat test (DST) device is a measure of the vitality of the sudomotor nerves that stimulate sweating. SGs whose nerves have degenerated cannot secrete water. Partially denervated and reinnervating SGs secrete smaller than normal sweat droplets. The DST measures SG density, distribution and total water volume. The DST also quantifies rate of sweating and amount of water of single SGs. This has an advantage over existing sweat tests that only measure total water produced at a skin location because sweating by normally secreting SGs can obscure a deficiency in a smaller number of partly or totally denervated SGs. In this sense the SG is the gateway to understanding the health of peripheral autonomic nerves.
Existing tests lack sensitivity to detect peripheral nerve disease early when it is most susceptible to treatment. Neuro Devices, Inc. will show that it is feasible to construct a device that can detect early signs of neuropathy in cancer patients with chemotherapy-induced neuropathy by measuring abnormalities of sweat rate and sweat volume secreted by individual sweat glands.