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Sudomotor Autonomic Assessments



SudoCheck is a quick and non-invasive test to assess peripheral autonomic neuropathy.

TopDocDX SudoCheck

A Clinical Powerful Easy To Use Non-Invasive System, FDA 510K Cleared. In 5 Minutes Identify Patients at Risk.

TopDocDX SudoCheck system helps clinicians with Peripheral Neuropathies and Sudomotor function evaluation. TopDocDX SudoCheck assessment focus on small nerve fibers within the autonomic nervous system, and their ability to quickly regenerate.

Small nerve fibers are the very first victims of diabetes, which is known to affect the peripheral nervous system even symptoms remain sub-clinical. According to a recent study, already at an early stage of the diabetes evolution, the sympathetic innervation of eccrine sweat glands density and function is progressively reduced.


TopDocDX SudoCheck has been created to enable a precise evaluation of sweat gland function. It is based on a measuring method, whereas patients place their hands and feet on stainless-steel electrodes. What is being tested is the electrochemical reaction between electrodes and chloride of the, through low voltage stimulated sweat glands. This active, new method provides information and evidence of a sweat dysfunction that might otherwise not be detectable in physiological conditions. Bioelectrical Conductances (BEC, in microsiemens, uS) for the hands and feet, express the quantitative results, while a risk score is derived from demographic data and the BEC values.

The TopDocDX SudoCheck system, in accordance with the 21 CFR 882.1540, represents a sympathetic skin response device that provides skin conductance measurements on a computer screen.

TopDocDX SudoCheck is, similar to a galvanic skin response stress test, an active test that measures the sweat glands' capacity to release chloride ions following an electrochemical stimulation. It works by measuring the electrical potential difference caused by the electrochemical reaction of electrodes, which are applied to the skin and are stimulated by a low voltage of variable amplitude. TopDocDX SudoCheck comes with 4x2 independent electrodes for placement on feet or palms and other areas with a high number of sweat glands.

TopDocDX SudoCheck provides information that determines the cardiometabolic risk in patients. The test, equivalent to a sympathetic skin response stress test, measures the sweat glands' capacity to release chloride ions in response to an electrochemical activation.
The advantages: TopDocDX SudoCheck does not require any patient preparation, such as blood drawing or fasting; it is non-invasive and delivers immediate results, with findings that are ready to use after a short and uncomplicated test of merely 3 minutes.
TopDocDX SudoCheck has been developed for use by general practitioners, pharmacists, cardiologists and neurologists to assist in the effective screening of cardiometabolic risk in patients.


Analytical Overview

  • Small unmyelinated C-fibers are responsible for the function of sweat glands

  • Sudomotor dysfunction has been established as one of the earliest detectable neurophysiologic abnormalities in distal small fiber neuropathies.

  • As an index of the severity and distribution of automatic failure, quantitative assessment of sweat response has been proposed. It will also serve as an early indicator for regeneration of small fibers.

  • Diabetic patients have been observed to experience a degeneration of small C-fiber innervating sweat glands.

  • TopDocDX SudoCheck measures bio electrochemical sweat skin conductances (BEC), which are directly connected to the capability of the glands to transfer chloride ions and which reflects small-C fiber status.

  • TopDocDX SudoCheck is a fast and easy method to measure sweat function.


  • Analyze and test TopDocDX SudoCheck's responsiveness and accuracy in detecting diabetic neuropathy and compare it with existing standardized tests for the diagnosis of diabetic neuropathy.

  • Evaluate TopDocDX SudoCheck in patients with Diabetes Mellitusm, as an instrument to assess autonomic neuropathy and neuropathic pain.

  • TopDocDX SudoCheck is an innovative, sensitive tool for the detection of diabetic neuropathy, especially painful diabetic neuropathy. As sweat glands are innervated by small c fibers, which are also involved in pain pathways, precise measuring of the sweat gland function can identify that cause.

  • TopDocDX SudoCheck, a sensitive device to detect neuropathy in patients with diabetes mellitus, operates with a sensitivity of 80% and a specificity of 95%.

  • When compared to non-painful neuropathy, feet BEC was significantly decreased in patients with painful diabetic neuropathy.

  • These results suggest that the peripheral autonomic nervous system plays a role in painful diabetic neuropathy.

  • TopDocDX SudoCheck results correlated significantly with clinical neuropathy scores, pain scores and measures of autonomic dysfunction.


Evaluation Of Sudomotor Function

Why evaluate sudomotor function?
The study of sudomotor presents a useful tool to assess autonomic disorders, as Sudomotor function is known to reflect sympathetic activity and to provide insight into postganglionic autonomous innervation.
Recent clinical studies have shown that conventional tests were influenced by level of glycemia. TopDocDX SudoCheck however has proven to be a reproducible and quantitative test method, which is not affected by that, and TopDocDX SudoCheck's Bio Electrochemical Sweat Conductance (BEC) reflects sympathetic dependent sweat function.

The need for a faster sudomotor function test
Sudomotor function assessment can now be carried out faster and simpler with the newTopDocDX SudoCheck technology.
In response to electrochemical activation, it measures the ability of sweat glands to release chloride ions and detects abnormalities. Once suspected or confirmed, more specialized tests are recommended to diagnose the underlying cause of the irregularity.


Evaluation of sudomotor function in diabetes
One of the major causes of nerve damage is diabetes. As diabetes patients suffer from metabolic impairment and related inflammatory processes, their non-myelinated axons of small fiber nerves are primarily affected, and known as Diabetic Autonomic Neuropathy (DAN), a subtype of peripheral neuropathies.
To validate TopDocDX SudoCheck's new technology for DAN detection, there are presently several clinical studies ongoing.

Small fiber nerves are early victims of diabetes
While symptoms remain sub-clinical, diabetes is known to affect the peripheral nervous system and small nerve fibers are usually among the first victims. TopDocDX SudoCheck has been developed as a new device to follow-up on complications related to diabetes.


Left side - Normal innervation of a sweat gland at the distal leg in a healthy person.
Right side - Reduced innervation of a sweat gland in a diabetic patient.

The TopDocDX Vascular+ system is a Class II medical device that is US FDA 510(K) cleared.

TopDocDX Vascular+ testing procedure is covered by the most major insurance providers, under CPT code 93922 and 93923.


Non-Invasive, Painless, Preventative Testing,  to

Prevent Possible Life Threatening Conditions From Before They Are A Threat

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