Assessment of Small Fiber Neuropathy in Rare Diseases Using Sudoscan

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.

Study Overview

• Status: Completed
• Conditions: Fabry Disease; Mitochondrial Disease; Small Fiber Neuropathy; Ehlers Danlos Syndrome
• Intervention / Treatment: Device: Sudoscan; Procedure: Skin biopsy; Procedure: QSART

Detailed 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.

• Study Type: Interventional
• Enrollment (Actual): 102
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 8 years to 70 years (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Sudoscan only; Patients in this arm will only undergoing testing with Sudoscan.	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.
Other: Sudoscan Plus; Patients in this arm will get Sudoscan testing as well as a skin biopsy and QSART testing.	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 Names: Quantitative Sudomotor Autonomic Reflex Testing

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Patients With Abnormal Electrochemical Skin Conductance in the Different Study Groups Who Have Clinical Symptoms Consistent With Small Fiber Polyneuropathy.	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	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Patients in Whom a Specific Skin Conductance (ESC) Signature Pattern Was Detected in the Hands and/or Feet on Sudoscan Measurements.	Distribution of the electrochemical skin conductance (ESC) in both hands and feet was reviewed as an indirect measure of the subject's capacity to sweat. Normative scales of adult sweat function are preloaded in the device and compared to actual measurements to determine if a subject's sweat response is reduced, which is associated with neuropathy. A positive outcome is the identification of a lower ESC in either hands or feet that distinguishes Fabry disease from other disorders and would be a reflection of the presence of SFPN.	48 months

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Investigators: Principal Investigator: Amel Karaa, MD, Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start: August 1, 2016
• Primary Completion (Actual): December 22, 2019
• Study Completion (Actual): August 1, 2020

Study Registration Dates

• First Submitted: September 12, 2016
• First Submitted That Met QC Criteria: December 5, 2016
• First Posted (Estimate): December 7, 2016

Study Record Updates

• Last Update Posted (Actual): October 7, 2021
• Last Update Submitted That Met QC Criteria: September 10, 2021
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Cardiovascular Diseases; Vascular Diseases; Metabolic Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Skin Diseases; Disease Attributes; Congenital Abnormalities; Hematologic Diseases; Hemorrhagic Disorders; Genetic Diseases, Inborn; Genetic Diseases, X-Linked; Connective Tissue Diseases; Neuromuscular Diseases; Peripheral Nervous System Diseases; Hemostatic Disorders; Skin Diseases, Genetic; Metabolism, Inborn Errors; Lysosomal Storage Diseases; Lipid Metabolism Disorders; Brain Diseases, Metabolic; Brain Diseases, Metabolic, Inborn; Skin Abnormalities; Sphingolipidoses; Lysosomal Storage Diseases, Nervous System; Cerebral Small Vessel Diseases; Lipidoses; Lipid Metabolism, Inborn Errors; Collagen Diseases; Mitochondrial Diseases; Fabry Disease; Rare Diseases; Ehlers-Danlos Syndrome; Small Fiber Neuropathy
• Other Study ID Numbers: 2015P000205

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: Scientific publication at the end of the study