Assessment of Small Fiber Neuropathy in Rare Diseases Using Sudoscan | oneedsvoice

welcome to oneEDSvoice

- a positively charged Ehlers Danlos Syndrome community.
  • join today!

Assessment of Small Fiber Neuropathy in Rare Diseases Using Sudoscan

study id #: NCT02985710

condition: Small Fiber Neuropathy, Fabry Disease, Ehlers Danlos Syndrome, Mitochondrial Disease

status: recruiting


Sudoscan™ (Impeto Medical, Paris France) uses electrochemical skin conductance as a novel noninvasive method to detect sudomotor dysfunction. Several small studies have recently shown that Sudoscan use in the assessment of small fiber polyneuropathy (in diabetes mellitus) can be performed non-invasively, quickly and effectively. The investigators aim to study the use of Sudoscan in rare disease condition associated with small fiber polyneuropathy.

intervention: Device: Sudoscan
The Sudoscan is a non invasive procedure and similar to standing on a scale to be weighed. Sudoscan measurements are made in compliance with the manufacturer's recommended procedures. The measurement is rapid and non-invasive, and requires no advance preparation.
Procedure: Skin biopsy
For subjects that give additional consent, skin biopsy will be done in standard fashion under sterile conditions. Assessment of nerve fiber density typically involves a 3-mm punch biopsy of skin from the leg (10 cm above the external malleolus).
Procedure: QSART
QSRT (quantitative sudomotor axon reflex test) testing involves having a technician wipe the subject's arms and leg with alcohol, then tissue to wipe it dry. Electrodes filled with acetylcholine are put on three areas of the leg and one on the wrist, stimulators are turned on and sweat responses are measured. Other Name: Quantitative Sudomotor Autonomic Reflex Testing

start date: August 2016

estimated completion: August 2019

last updated: August 16, 2018

phase of development: N/A

size / enrollment: 100

study design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic

study description: Small fiber polyneuropathy (SFPN) is diagnosed through a combination of symptoms, signs and confirmatory diagnostic testing. Nerve conduction studies are not sensitive enough in most of the cases leaving the ankle skin biopsy with measurement of intraepidermal nerve fiber density (IENFD) as the main diagnostic tool. Despite its utility and reproducibility, skin biopsy is invasive, expensive and requires a central laboratory for processing and interpretation. Quantitative sudomotor axon reflex testing (QSART) is also routinely used for evaluation of small fiber neuropathy as sudomotor axons can also be involved. This test however remains technically challenging and requires testing conditions in specialized labs that are not always suitable for all patients' population. By comparing findings on skin biopsy and/or QSRT, accepted gold standard for diagnosing SFPN, the investigators seek to find faster, less-invasive ways to diagnose and monitor small-fiber polyneuropathy in rare diseases using Sudoscan measurement.

primary outcomes:

  • Number of patients with abnormal electrochemical skin conductance in the different study groups who have clinical symptoms consistent with small fiber polyneuropathy. [ Time Frame:12 months ] The internal software of the Sudoscan will allow analysis of skin conductance in all patients and quantification into normal or abnormal. Correlation of an abnormal conductance measurement with clinical symptoms and signs of small fiber neuropathy will be evaluated for accuracy of Sudoscan measurements

secondary outcomes:

  • Number of patients with skin biopsy and QSART consistent with a small fiber polyneuropathy who also had abnormal skin conductance finding on Sudoscan measurements. [ Time Frame:12 months ]

inclusion criteria: - Males and females with confirmed disease: Fabry (by GLA enzymes and/or DNA testing) naïve and on ERT, Mitochondrial diseases (electron transport chain and/or DNA testing) or connective tissue diseases (clinical criteria and/or DNA testing when available)
- Consenting adults (18 years and older) who agrees and consents to skin biopsy and QSART procedure

exclusion criteria: - Subjects with cognitive, psychiatric, or other problems that preclude informed consent.
- Patients with history of glucose intolerance or diabetes.
- Patient on chemotherapy
- People with any open or bleeding wounds at any sensor plate contact surface location
- People with any type of implantable device
- People with missing hand(s) and/or leg(s)
- Pregnant women or women who are uncertain about a possible pregnancy
- Patients sensitive to chemicals used to induce sweating
- Patients with heat intolerance
- Patients with bleeding disorders
- Patients on current anticoagulant therapy
- Patients with keloids on the intended biopsy site
- People with hypersensitivity to local amide-type anesthetics

sponsor: Massachusetts General Hospital

contacts: Erica L Kelly, 617 724 7726,

investigators: Amel Karaa MD, Massachusetts General Hospital

locations: United States