Pilot Study to Evaluate Changes in Intra-Epidermal Nerve Fiber Density (IENFD) in Patients With Small-Fiber Neuropathy

NCT07704931 | Enrolling By Invitation FDA Device

• 1 other identifier: SAL 002
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective observational pilot study will evaluate structural, functional, and patient-reported outcomes in adults with small fiber neuropathy who receive Saluda Evoke ECAP-controlled spinal cord stimulation as part of routine clinical care. The study does not assign, direct, or modify spinal cord stimulation therapy. All decisions regarding patient selection, trial stimulation, permanent implantation, and device programming are made independently by the treating physician according to standard clinical practice. The primary objective is to assess change in intra-epidermal nerve fiber density from baseline to 12 months. Secondary objectives include evaluation of quantitative sensory testing, pain intensity, patient-reported outcomes, and correlations between changes in nerve fiber density, sensory function, and neuropathic pain outcomes. The study will enroll up to 10 adult participants with clinically diagnosed small fiber neuropathy and chronic neuropathic pain. Research assessments include patient-reported outcome measures, quantitative sensory testing, review of available clinical records, and a 12-month follow-up skin biopsy for intra-epidermal nerve fiber density. This aligns with the approved protocol: observational, 10 adults, 12-month participant follow-up, primary IENFD endpoint, and secondary QST/pain/correlation endpoints.

Conditions

Small Fiber Neuropathy

Keywords

Small Fiber Neuropathy; Intra-Epidermal Nerve Fiber Density; IENFD; Spinal Cord Stimulation; SCS; ECAP-Controlled Stimulation; Closed-Loop Stimulation; Saluda Evoke; Quantitative Sensory Testing; QST; Neuropathic Pain; Mixed Neuropathy; EMG/NCS

Outcome Measures

Primary Outcomes (1)

• Change in Intra-Epidermal Nerve Fiber Density From Baseline to 12 Months

  Change in intra-epidermal nerve fiber density measured by skin biopsy from baseline to 12 months in participants with small fiber neuropathy receiving ECAP-controlled spinal cord stimulation as part of routine clinical care.

  Baseline to 12 months

Secondary Outcomes (5)

• Change in Thermal Detection Thresholds From Baseline to 12 Months

  Baseline to 12 months

• Change in Numeric Pain Rating Scale Score Over 12 Months

  Baseline, 1 week, 3 months, 6 months, and 12 months

• Patient Global Impression of Change Score Over 12 Months

  1-week, 3 months, 6 months, and 12 months

• Correlation Between Change in IENFD and Change in Quantitative Sensory Testing Thresholds

  Baseline to 12 months

• Correlation Between Change in IENFD and Change in Pain Intensity

  Baseline to 12 months

Study Arms (1)

Saluda Evoke ECAP-Controlled Spinal Cord Stimulation System

OTHER

Participants with clinically diagnosed small fiber neuropathy and chronic neuropathic pain who receive Saluda Evoke ECAP-controlled spinal cord stimulation as part of routine clinical care will be followed for 12 months. The study does not assign, direct, or modify spinal cord stimulation therapy. All treatment decisions, including trial stimulation, permanent implantation, and device programming, are made independently by the treating physician according to standard clinical practice. Outcomes include intra-epidermal nerve fiber density, quantitative sensory testing, pain intensity, and patient-reported measures.

Device: Evoke SCS system

Interventions

Evoke SCS system DEVICE

Spinal cord stimulation using the Saluda Evoke system, an ECAP-controlled closed-loop SCS device that monitors neural response and adjusts stimulation in real time. Participants receive SCS therapy as part of routine clinical care. The study observes structural, sensory, pain, and patient-reported outcomes over 12 months and does not assign, direct, or modify device use, implantation, or programming. This matches the protocol's device description and keeps the intervention generic enough for ClinicalTrials.gov while still identifying the Saluda Evoke system.

Also known as: ECAP-Controlled Spinal Cord Stimulation, Closed-Loop Spinal Cord Stimulation

Saluda Evoke ECAP-Controlled Spinal Cord Stimulation System

Eligibility Criteria

• Age: 19 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 19 years or older.
• Clinically diagnosed small fiber neuropathy based on abnormal intra-epidermal nerve fiber density (IENFD) skin biopsy.
• Chronic neuropathic pain with Numeric Pain Rating Scale score of at least 6.
• Candidate for ECAP-controlled spinal cord stimulation therapy based on the - - - Principal Investigator's medical judgment.
• Able and willing to undergo baseline and 12-month skin biopsies.
• Able to comply with 12-month quantitative sensory testing.
• Able to provide informed consent.

You may not qualify if:

• Confounding factors that may independently contribute to small fiber damage or alter nerve fiber density, including uncontrolled diabetes defined as HbA1c greater than 8.5% within the last 3 months, autoimmune disorders such as lupus, or history of alcohol abuse.
• Contraindications to spinal cord stimulation therapy, including active infection, coagulation disorders, allergy to medical device components, or other relevant surgical/device contraindications.
• Uncontrolled medical or psychiatric conditions.
• Pregnancy or planning to become pregnant during the study period.

Sponsors & Collaborators

• TriCity Research Center: lead
• Saluda Medical Americas, Inc.: collaborator

Study Sites (1)

Grand Island Pain Relief Center

Grand Island, Nebraska, 68803, United States

Location

MeSH Terms

Conditions

Small Fiber Neuropathy; Neuralgia

Condition Hierarchy (Ancestors)

Peripheral Nervous System Diseases; Neuromuscular Diseases; Nervous System Diseases; Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Pravardhan Birthi, M.D.

  TriCity Research Center, LLC

  PRINCIPAL INVESTIGATOR

• Mahesh Pattabiraman, Ph.D.

  TriCity Research Center

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 7, 2026
• First Posted: July 15, 2026
• Study Start: July 1, 2026
• Primary Completion (Estimated): September 30, 2027
• Study Completion (Estimated): October 30, 2027
• Last Updated: July 15, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)