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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Laser acupuncture for carpal tunnel syndrome: A randomized controlled trial using low-level laser intervention
Scientific title
Laser acupuncture for carpal tunnel syndrome: A randomized controlled trial using low-level laser intervention
Secondary ID [1] 283069 0
IRB 9827
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
carpal tunnel syndrome 289907 0
Condition category
Condition code
Alternative and Complementary Medicine 290273 290273 0 0
Other alternative and complementary medicine

Study type
Description of intervention(s) / exposure
laser acupuncture treatment indicates using Low level laser (class IIIb lasers, 400mw, near infrared, continuous wavelength, 810nm, LaserPenR, RJ-LASER, Germany) in traditional Chinese acu-points (PC -7 (Daling), PC-6 (Neiguan)) on the affected side. Laser acupuncture consisted of once per day for five consecutive days followed by a two-day break with a total of 20 sessions in four weeks period. Each stimulation was performed in the continuous wave mode for 1 minute. The energy transferred to the skin in a treatment of 1 minute was up to approximately 24 J/cm2.
Intervention code [1] 287789 0
Treatment: Devices
Comparator / control treatment
Placebo laser acupuncture administered by the same device with same protocol as for true laser stimulation, but the laser apparatus was not switched on
Control group

Primary outcome [1] 290306 0
global symptom score (GSS)
Timepoint [1] 290306 0
baseline and 2 and 4 weeks and 1 year later
Primary outcome [2] 290307 0
Primary outcome measure was the difference in modified GSS between the verum and placebo group. This scale has been used to evaluate treatment responses in various previous studies.This assessment was to rate clinical symptoms from 0 (no symptoms) to 10 (very severe symptoms) in the following five symptom categories: pain, numbness, tingling, weakness/clumsiness, and nocturnal awakening. Each patient was directly questioned, and each score was based on the patient’s subjective answers. Therefore, the maximum score was 50 (most severe symptoms) and the minimum score was 0 (absence of symptoms). To ensure consistency, the evaluating physician who scored the main outcome measure, GSS, was the same person on each occasion for each patient and was blinded to the type of treatment. Patients completed standard questionnaires at baseline and 2 and 4 weeks later.
Timepoint [2] 290307 0
baseline and 2 and 4 weeks and 1 year later
Secondary outcome [1] 304284 0
Secondary outcomes measures were change in GSS reduction and all parameters of nerve conduction study (NCS) at different time phases compared to baseline and in comparison of verum laser acupuncture with placebo laser acupuncture. We defined a reduction of GSS more than 50% as good improvement, 30-50% as moderate improvement, and less than 30%, being lost to follow-up, showing APB muscle wasting, or receiving surgery or other conservative treatment as treatment failure for secondary outcome measures.
Timepoint [1] 304284 0
nerve conduction studies (NCS) at baseline, 4 weeks and 12 months later

Key inclusion criteria
The inclusion criteria for treatment naïve patients, aged from 20 to 65, enrolled in this study were based on a combination of clinical and electrodiagnosis of mild or moderate idiopathic CTS. The CTS diagnosis was based on the presence of at least one of the following symptoms: 1) pain, numbness or paresthesia in the median nerve distribution; 2) precipitation of these sensory complaints by forceful or repetitive hand use which could be relieved by resting, rubbing and shaking the hands; and 3) awakening from sleep due to such sensory symptoms. The diagnosis was often supported by a positive Tinel’s sign or Phalen’s test. All patients with clinically diagnosed CTS demonstrated median neuropathy at the wrist, confirmed by the presence of one or more of the following standard electrophysiological criteria: 1) prolonged distal motor latency (DML) to the abductor pollicis brevis (APB) (abnormal = 4.7 ms; wrist to APB, 8 cm); 2) prolonged anti-dromic distal sensory latency (DSL) to the second digit (abnormal = 3.1 ms; wrist to index finger, 14 cm); and 3) prolonged anti-dromic wrist-palm sensory nerve conduction velocity (W-P SNCV) at a distance of 8 cm (W-P SNCV, abnormal < 45 m/s). In our study, mild CTS referred to patients with decreased conduction velocity over the palm-wrist segment and delayed DSL, with normal median sensory nerve action potential (SNAP) amplitude and compound muscle action potential (CMAP) amplitude of the APB. Moderate CTS referred to patients with abnormally delayed DML and DSL with either decreased median SNAP amplitude or decreased CMAP amplitude of the APB muscle. Thus, CTS patients with the presence of either fibrillation potentials or re-innervation on needle electromyography (EMG) in the APB were considered severe CTS.
Minimum age
20 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Patients were excluded if any of the following were present: (1) Symptoms occurring less than three months before the study (to exclude patients who might have spontaneous resolution of symptoms); (2) Severe CTS that had progressed to visible muscle atrophy; (3) Clinical or electrophysiological evidence of accompanying conditions that could mimic CTS or interfere with its evaluation, such as cervical radiculopathy, proximal median neuropathy, or significant polyneuropathy; (4) Evidence of obvious underlying etiologic factors of CTS such as diabetes mellitus, rheumatoid arthritis, hypothyroidism (acromegaly), pregnancy, alcohol abuse or drug usage (steroids or drugs acting through the central nervous system), and suspected malignancy or inflammation or autoimmune disease were documented as underlying causes for CTS; or (5) Cognitive impairment interfering with the subject’s ability to follow instructions and describe symptoms.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Written informed consent was obtained from all study subjects in the presence of a witness. Potential subjects for the study were offered by a face-to-face appointment for formal assessment. The aim and methods of the study were explained to all patients before their informed consent was given. Patients were informed that they would be randomly assigned to one of the two different laser acupuncture formulas with equal chance.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
This is a single blind trial, in which patients could not tell the differences between the verum laser acupuncture (invisible near infrared laser emission and red light) and placebo laser acupuncture (red light). There was little chance of communication between patients because most of them came at different times. The outcome measurements were evaluated by blinded assessors and the statistical analyzers were uninvolved in the clinical management thus, were unaware of patient location. However, the laser acupuncture practitioners failed to be blinded. Patients were randomly allocated to start with either verum or sham laser acupuncture treatment. The randomization list was compiled by an external physician and was not divulged to study practitioners or patients. The same physician prepared a series of sealed, sequentially numbered envelopes containing the treatment assignments. When a patient fulfilled the inclusion criteria, the study physician physician opened the low least numbered envelop to reveal the patient’s group allocation. This procedure assured that randomization would not influenced either by the physicians, outcome assessors or the patients.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

Intervention assignment
Other design features
single blinded
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
With a two-sided test, significance level of 0.05, power of 80%, standard deviation of 4.5, and 20% drop-out rate, at least 45 subjects per treatment was required to detect a difference of 3.0 in mean reduction of Global Symptom Score (GSS) from baseline between the two groups. last-observation-carried-forward approach was used to impute missing data, and the intent-to-treat analysis principle was adopted. If patients reported symptoms in both hands, we included the more-affected hand with a higher GSS in each individual for data analysis.
The means and standard deviations were calculated for all subjects in each group for each parameter. Independent 2-sample t test was performed to compare the efficacy of the objective changes in nerve conduction and subjective symptoms assessment between
the two groups for the baseline, 2-week and 4-week evaluations. For 5 main symptoms score of GSS and 6 measures of NCS, Bonferroni adjustment was made to control for type I error. Paired t test was performed for objective changes in nerve conduction and subjective symptoms assessment between week 2/4 data and baseline within each treatment group with Bonferroni adjustment. Repeated measures analysis of variance (ANOVA) was used to compare the values in subjective symptoms assessment over time between groups. All hypothesis testings were 2-tailed and level of significance was set at 0.05. All statistical analyses were performed using SPSS Version 15.0 for Windows (SPSS Inc, Chicago, IL).

Recruitment status
Active, not recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 5338 0
Taiwan, Province Of China
State/province [1] 5338 0

Funding & Sponsors
Funding source category [1] 287840 0
Name [1] 287840 0
Kaung-Tien general hospital
Address [1] 287840 0
No.117, Shatian Road Shalu District, Taichung City 433, Taiwan (R.O.C.)
Country [1] 287840 0
Taiwan, Province Of China
Primary sponsor type
Kaung-Tien general hospital
No.117, Shatian Road Shalu District, Taichung City 433, Taiwan (R.O.C.)
Taiwan, Province Of China
Secondary sponsor category [1] 286567 0
Name [1] 286567 0
Hungkuang University
Address [1] 286567 0
No. 1018, Sec. 6, Taiwan Boulevard, Shalu District, Taichung City 43302, Taiwan (R.O.C.)
Country [1] 286567 0
Taiwan, Province Of China

Ethics approval
Ethics application status
Ethics committee name [1] 289779 0
The institutional review board of Kuang-Tien General Hospital
Ethics committee address [1] 289779 0
No.117, Shatian Road Shalu District, Taichung City 433, Taiwan (R.O.C.)
Ethics committee country [1] 289779 0
Taiwan, Province Of China
Date submitted for ethics approval [1] 289779 0
Approval date [1] 289779 0
Ethics approval number [1] 289779 0

Brief summary
Objectives: To investigate the efficacy of laser acupuncture compared with placebo laser acupuncture treatment in patients with mild-to-moderate carpal tunnel syndrome (CTS) as measured by subjective symptoms assessment and objective changes in nerve conduction studies (NCS) in a randomized, controlled study. Methods: A total of 84 consecutive and prospective CTS patients confirmed by NCS were enrolled in the study. The CTS patients were randomly divided into 2 treatment arms: (1) Laser acupuncture administered in traditional Chinese acu-points (PC -7 (Daling), PC-6 (Neiguan)) on the affected side once a a day, 5 times a week, for 4 weeks (n=43), and (2) Placebo laser acupuncture administered by the same device with same protocol as for true laser stimulation, but the laser apparatus was not switched on (n=41). A validated global symptom score (GSS) as a subjective measurement was used to rate the 5 major symptoms (pain, numbness, paresthesia, weakness/clumsiness, and nocturnal awakening) on a scale from 0 (no symptoms) to 10 (very severe). Patients completed GSS at baseline and 2 and 4 weeks later. The changes in GSS were analyzed to evaluate the subjective symptoms improvement for primary outcome. NCS were performed at baseline and repeated at the end of the study to assess objective improvement for secondary outcome. All main analyses used intent-to-treat.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 42354 0
Dr Yang, chun-pai
Address 42354 0
No.321, Jingguo Road Dajia District, Taichung City 437, Taiwan (R.O.C.)
Country 42354 0
Taiwan, Province Of China
Phone 42354 0
Fax 42354 0
Email 42354 0
Contact person for public queries
Name 42355 0
Dr Yang,chun-pai
Address 42355 0
No.321, Jingguo Road Dajia District, Taichung City 437, Taiwan (R.O.C.)
Country 42355 0
Taiwan, Province Of China
Phone 42355 0
Fax 42355 0
Email 42355 0
Contact person for scientific queries
Name 42356 0
Dr Yang,chun-pai
Address 42356 0
No.321, Jingguo Road Dajia District, Taichung City 437, Taiwan (R.O.C.)
Country 42356 0
Taiwan, Province Of China
Phone 42356 0
Fax 42356 0
Email 42356 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary