Low-Level Laser Therapy for Carpal Tunnel Syndrome

Efficacy of Low-Level Laser Therapy on Symptom Severity, Functionality, Ultrasonographic and Electrophysiological Parameters in Carpal Tunnel Syndrome: A Randomized, Sham-Controlled, Assessor-Blind Trial

Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy, caused by compression of the median nerve within the carpal tunnel at the wrist. It typically presents with paresthesia, numbness, and pain in the median nerve distribution, and in advanced cases may lead to thenar atrophy and reduced grip strength. Conservative treatment options for mild-to-moderate CTS include wrist splinting, exercise programs, and physical therapy modalities such as low-level laser therapy (LLLT) and paraffin bath therapy; however, the comparative efficacy of these modalities has not been well established.

This study aims to compare the efficacy of low-level laser therapy (LLLT), paraffin bath therapy, and sham LLLT, each combined with standard conservative care (night wrist splinting and tendon/nerve gliding exercises), in patients with mild-to-moderate CTS. Participants will be randomly assigned in a 1:1:1 ratio to receive LLLT, paraffin bath therapy, or sham LLLT, each administered 5 days/week for 3 weeks (15 sessions), in addition to wrist splinting and a home exercise program continued throughout the study.

The primary outcome is the change in symptom severity and functional status, assessed using the Symptom Severity Scale (SSS) and Functional Status Scale (FSS) of the Boston Carpal Tunnel Questionnaire. Secondary outcomes include electrophysiological parameters from median nerve conduction studies, median nerve cross-sectional area on ultrasonography, grip and pinch strength, pain (Visual Analog Scale), and hand function (QuickDASH). Assessments will be performed before treatment, immediately after completing 15 sessions, and at 3 months after treatment completion. Outcome assessors will be blinded to treatment allocation.

The investigators hypothesize that LLLT will result in greater improvement in clinical, electrophysiological, and morphological parameters compared with sham LLLT, and will provide comparative data on its efficacy relative to paraffin bath therapy.

Inclusion Criteria:

• Diagnosis of mild-to-moderate carpal tunnel syndrome (unilateral or bilateral), confirmed by paresthesia and pain in the median nerve distribution, positive Tinel's and Phalen's signs on physical examination, and electrophysiologically confirmed mild-to-moderate CTS
• Age 18 years or older
• No cognitive impairment
• Provision of informed consent to participate in the study

Exclusion Criteria:

• Cognitive impairment
• Severe-stage CTS with surgery planned
• Neurological disease affecting the extremity with CTS
• Active local infection at the treatment site (e.g., cellulitis, erysipelas, thrombophlebitis) contraindicating physical therapy
• Cardiac pacemaker (contraindication to physical therapy and electrodiagnostic studies)
• Prior wrist fracture or laceration at the treatment site
• Injection therapy for CTS within the past 3 months
• Prior CTS surgery with recurrence
• Active malignancy under treatment
• Pregnancy