High-Intensity Laser Therapy in Carpal Tunnel Syndrome: Clinical, Sonographic, and Electrophysiological Outcomes

Evaluation of the Clinical, Sonographic, and Electrophysiological Efficacy of High-Intensity Laser Therapy (HILT) in Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy of the upper extremity and is characterized by pain, paresthesia, and functional impairment resulting from increased pressure within the carpal tunnel. Although conservative treatment approaches such as splinting and pharmacological therapy are commonly used, High-Intensity Laser Therapy (HILT) has emerged as a non-invasive modality with potential analgesic, anti-inflammatory, and biostimulatory effects. However, evidence regarding its efficacy remains limited, particularly from sham-controlled studies incorporating objective outcome measures. This prospective, randomized, double-blind, sham-controlled clinical trial aims to evaluate the clinical, sonographic, and electrophysiological effectiveness of HILT in patients with mild-to-moderate CTS. Eligible patients aged 18 to 65 years with electrophysiologically confirmed mild-to-moderate CTS will be randomized into two groups: a HILT group and a sham HILT group. Both groups will receive standard wrist splinting as part of conservative management. Clinical outcomes will be assessed using Visual Analog Scale (VAS) scores for pain, Boston Carpal Tunnel Questionnaire (BCTQ) scores for symptom severity and functional status, and grip strength measurements. Objective evaluations will include median nerve sensory and motor nerve conduction studies and ultrasonographic measurement of the median nerve cross-sectional area at the proximal carpal tunnel level. Assessments will be performed at baseline and at 1 and 3 months after treatment. This study aims to provide robust and objective evidence regarding the therapeutic effectiveness of HILT in the conservative management of carpal tunnel syndrome.

Study Overview

• Status: Recruiting
• Conditions: Carpal Tunnel Syndrome
• Intervention / Treatment: Device: High-Intensity Laser Therapy (HILT); Device: Sham High-Intensity Laser Therapy

Detailed Description

Carpal Tunnel Syndrome (CTS) is the most common entrapment neuropathy of the upper extremity, characterized by the compression of the median nerve due to increased pressure within the carpal tunnel. While conservative management strategies such as splinting and physical therapy modalities are the standard approach, High-Intensity Laser Therapy (HILT) has recently emerged as a potent, non-invasive therapeutic option . Utilizing an Nd:YAG laser source, HILT penetrates deep tissues to induce photochemical and photothermal effects. It is hypothesized to promote tissue repair by increasing ATP synthesis at the mitochondrial level, regulating Na/K pump activity, and providing analgesia by suppressing inflammatory mediators .

Although HILT is used in clinical practice, there is a scarcity of sham-controlled, double-blind studies that comprehensively evaluate its efficacy using a combination of clinical, electrophysiological, and ultrasonographic (median nerve cross-sectional area) parameters .

Study Objective: The primary objective of this prospective, randomized, double-blind, sham-controlled trial is to provide evidence-based data on the efficacy of HILT regarding pain, hand function, grip strength, nerve conduction velocities, and median nerve morphology (ultrasonographic cross-sectional area) in patients with mild-to-moderate CTS.

Study Population and Design: Patients aged 18-65 years presenting to the Physical Therapy Clinic with clinically and electrophysiologically confirmed 80 patient hand mild-to-moderate CTS will be recruited.

Outcome Measures and Timeline: Assessments will be performed by independent blinded researchers at Baseline, Month 1, and Month 3 post-treatment.

• Clinical Assessment: Pain intensity (Visual Analog Scale - VAS), symptom severity and functional status (Boston Carpal Tunnel Questionnaire - BCTQ), gross grip strength (Hand Dynamometer), and pinch strength (Pinchmeter) .
• Ultrasonographic Assessment: Measurement of the median nerve Cross-Sectional Area (CSA) at the proximal carpal tunnel inlet.
• Electrophysiological Assessment: Sensory and motor nerve conduction studies of the median nerve (evaluating distal latency, conduction velocity, and amplitude).

This study aims to demonstrate the multifaceted contribution (clinical, anatomical, and physiological) of HILT to nerve recovery by reducing edema and inflammation in the pathophysiology of CTS.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ceren FINDIK KILIÇ; Phone Number: +905312689928; Email: crn.fndk@gmail.com

Study Locations

• Turkey (Türkiye)
  • Ankara, Çankaya
    • Ankara, Ankara, Çankaya, Turkey (Türkiye), 06800
      • Recruiting
      • Ankara Bilkent City Hospital
      • Contact: Filiz Eser; Phone Number: +905067388171; Email: filizeser@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age between 18 and 65 years
• Clinical symptoms consistent with carpal tunnel syndrome
• Electrophysiologically confirmed mild or moderate carpal tunnel syndrome
• Ability to comply with the study protocol and follow-up assessments
• Provided written informed consent

Exclusion Criteria:

• Severe carpal tunnel syndrome on electrophysiological examination
• Previous surgical treatment for carpal tunnel syndrome
• Local causes of carpal tunnel syndrome (e.g., mass lesions, ganglion cysts, tumors)
• Systemic conditions associated with carpal tunnel syndrome (e.g., diabetes mellitus, hypothyroidism, pregnancy, acromegaly)
• History of corticosteroid injection for carpal tunnel syndrome within the last 6 months
• Presence of polyneuropathy, radiculopathy, or other upper extremity peripheral nerve disorders
• Contraindications to electrophysiological testing or laser therapy
• Inability to complete follow-up assessments

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High-Intensity Laser Therapy (HILT); Patients in this group will receive High-Intensity Laser Therapy (HILT) in addition to using a neutral wrist splint. The treatment will consist of a total of 10 sessions, administered 5 days per week for a duration of 2 weeks.	Device: High-Intensity Laser Therapy (HILT); Procedure: The laser is applied to the carpal tunnel area while the patient's forearm is in supination. Device Specifications: Pulsed Nd:YAG laser source with Peak Power >3000 W, Intensity (max) 15,000 W/cm², Frequency 10-30 Hz, Pulse duration ≤ 100 μs, and a spot size of 0.5 cm diameter (0.2 cm²). Treatment Protocol (3 Phases): Initial Rapid Scan (3 Steps):Step 1: 25 Hz, 510 mJ/cm², 139 J energy.Step 2: 20 Hz, 610 mJ/cm², 139 J energy.Step 3: 19 Hz, 710 mJ/cm², 139 J energy.; Trigger Point Phase: Applied to painful points on the affected side.Step 1: 15 Hz, 360 mJ/cm², 6.3 J energy.Step 2: 15 Hz, 510 mJ/cm², 9 J energy.Step 3: 14 Hz, 610 mJ/cm², 10.1 J energy (applied for 6 seconds per point).; Final Slow Scan: Performed using the same parameters as the rapid scan phase. Total Energy: A total of 835 Joules is delivered per session.
Sham Comparator: Sham High-Intensity Laser Therapy; Patients in this group will receive sham (placebo) laser therapy in addition to using a neutral wrist splint. The treatment will consist of a total of 10 sessions, administered 5 days per week for a duration of 2 weeks.	Device: Sham High-Intensity Laser Therapy; The same HIRO TT device is used with the same positioning and duration as the experimental group. The device provides auditory and visual cues identical to the active treatment, but no laser energy is emitted to the tissue. Participants will also use a standard wrist splint.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Severity assessed by Visual Analog Scale (VAS)	Pain intensity will be evaluated using the Visual Analog Scale (VAS). This is a self-reported scale ranging from 0 to 10, where 0 indicates "no pain" and 10 indicates "severe pain". Higher scores indicate a worse outcome (greater pain intensity).	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Symptom Severity and Functional Status assessed by Boston Carpal Tunnel Questionnaire (BCTQ)	The BCTQ consists of two subscales: the Symptom Severity Scale (SSS) and the Functional Status Scale (FSS). The SSS has 11 items and the FSS has 8 items. Each item is scored on a scale from 1 to 5, where 1 indicates "no symptoms/no difficulty" and 5 indicates "severe symptoms/cannot perform activity". The final score is calculated as the mean of the items. Higher scores indicate a worse outcome (more severe symptoms and greater functional impairment).	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Median Nerve Cross-Sectional Area(CSA)	The cross-sectional area of the median nerve will be measured by ultrasonography at the proximal carpal tunnel level. In Carpal Tunnel Syndrome (CTS), the nerve typically swells due to edema and inflammation. A decrease in the cross-sectional area indicates a positive response to treatment. Unit of Measure: Square millimeters (mm²) Interpretation: Lower values indicate a better clinical outcome (reduction in nerve edema).BE	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period
Hand Grip Strength	Evaluation of the maximum isometric strength of the hand and forearm muscles using a hydraulic hand dynamometer (Baseline® hydraulic LCD hand dynamometer). The measurement is performed with the patient seated, elbow flexed at 90 degrees and wrist in a neutral position. The average of three measurements is recorded. Interpretation: Higher scores indicate a better outcome. An increase in grip strength suggests improved muscular function and a reduction in the inhibitory effects of pain and nerve compression caused by Carpal Tunnel Syndrome. Unit of Measure: Kilograms (kg)	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Pinch Strength (Lateral Pinch)	Description: Evaluation of the strength of the pinch between the thumb and the index finger using a hydraulic pinch gauge (Baseline® hydraulic LCD pinch gauge). Lateral pinch is measured by asking the patient to press between the pad of the thumb and the lateral aspect of the index finger. Interpretation: Higher scores indicate a better outcome. Improved pinch strength reflects better coordination and strength of the intrinsic hand muscles innervated by the median nerve. Unit of Measure: Kilograms (kg)	Time Frame: At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Median Nerve Motor Distal Latency (MDL)	Evaluation of the motor component of the median nerve using an Electroneuromyography (ENMG) device (Nihon Kohden Neuropack 2). MDL reflects the time taken for an electrical impulse to travel from the wrist to the thenar muscle. Unit of Measure: Milliseconds (ms) Interpretation: Lower scores (shorter latency) indicate a better outcome. A decrease in latency suggests improved nerve conduction across the carpal tunnel, reflecting a reduction in nerve compression.	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Median Nerve Compound Muscle Action Potential (CMAP) Amplitude	Measurement of the motor action potential amplitude, reflecting the integrity of the motor axons and neuromuscular junctions. Unit of Measure: Millivolts (mV) Interpretation: Higher amplitudes indicate a better outcome. An increase in amplitude suggests better motor axon recruitment and improved neuromuscular function.	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Median Nerve Sensory Conduction Velocity (Palmar)	Description: Measurement of the sensory conduction speed of the median nerve in the palmar segment (palm-to-wrist). This segment is often more sensitive to early compression within the carpal tunnel. Interpretation: Higher scores (faster velocity) indicate a better outcome. An increase in velocity indicates improved nerve function in the specific segment where compression is most prominent. Unit of Measure: Meters per second (m/s)	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Median Nerve Sensory Conduction Velocity (SCV)(Digit 2)	Description: Evaluation of the sensory conduction speed of the median nerve recorded from the 2nd digit to the wrist. It measures how fast electrical impulses travel through the distal part of the nerve. Interpretation: Higher scores (faster velocity) indicate a better outcome. An increase in velocity suggests that the sensory fibers of the median nerve are recovering and conducting signals more efficiently. Unit of Measure: Meters per second (m/s)	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Median Nerve Sensory Action Potential (SNAP) Amplitude (Palmar)	Description: Peak-to-peak measurement of the electrical response of the median nerve sensory fibers, recorded from the palmar segment to the wrist. Interpretation: Higher amplitudes indicate a better outcome. An increase in palmar SNAP amplitude indicates a recovery in the number of sensory fibers successfully conducting through the carpal tunnel. Unit of Measure: Microvolts (µV)	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.
Median Nerve Sensory Action Potential (SNAP) Amplitude (Digit 2)	Description: Peak-to-peak measurement of the electrical response of the median nerve sensory fibers, recorded from the 2nd digit. Interpretation: Higher amplitudes indicate a better outcome. Increased amplitude reflects a greater number of healthy, functioning sensory axons and improved nerve integrity. Unit of Measure: Microvolts (µV)	At baseline (pre-treatment), and at 1 and 3 months following the conclusion of the 2-week treatment period.

Collaborators and Investigators

• Sponsor: Ankara City Hospital Bilkent
• Investigators: Principal Investigator: Filiz Eser, professor, Ankara City Hospital Bilkent

Publications and helpful links

General Publications

• Yigit F, Ordahan B. Effects of high-intensity laser therapy on pain, functional status, hand grip strength, and median nerve cross-sectional area by ultrasonography in patients with carpal tunnel syndrome. Lasers Med Sci. 2023 Oct 31;38(1):248. doi: 10.1007/s10103-023-03913-z.
• de la Barra Ortiz HA, Avila MA, Parizotto NA, Liebano RE. A systematic review and meta-analysis of the effectiveness of high-intensity laser therapy in patients with carpal tunnel syndrome. Physiotherapy. 2025 Sep;128:101780. doi: 10.1016/j.physio.2025.101780. Epub 2025 Mar 5.

Study record dates

Study Major Dates

• Study Start (Actual): November 2, 2025
• Primary Completion (Estimated): March 5, 2026
• Study Completion (Estimated): April 30, 2026

Study Registration Dates

• First Submitted: January 14, 2026
• First Submitted That Met QC Criteria: February 12, 2026
• First Posted (Actual): February 17, 2026

Study Record Updates

• Last Update Posted (Actual): February 17, 2026
• Last Update Submitted That Met QC Criteria: February 12, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Carpal Tunnel Syndrome; Median Nerve; High-Intensity Laser Therapy; HILT; Entrapment Neuropathy
• Additional Relevant MeSH Terms: Nervous System Diseases; Wounds and Injuries; Neuromuscular Diseases; Genetic Diseases, Inborn; Peripheral Nervous System Diseases; Neurodegenerative Diseases; Congenital Abnormalities; Heredodegenerative Disorders, Nervous System; Nervous System Malformations; Polyneuropathies; Median Neuropathy; Mononeuropathies; Nerve Compression Syndromes; Cumulative Trauma Disorders; Sprains and Strains; Hereditary Sensory and Motor Neuropathy; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Charcot-Marie-Tooth Disease; Carpal Tunnel Syndrome
• Other Study ID Numbers: 1-24-647

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No