study of long term effects of laser therapy versus local corticosteroid injection in patients with carpal tunnel syndrome

introduction:  carpal tunnel syndrome (cts) is the most common compressive neuropathy. several surgical and nonsurgical treatments have been proposed for this syndrome, but there is no consensus regarding the prioritization of the suggested nonsurgical treatments. the goal of this study was to compare the long term effects of laser therapy versus local corticosteroid injection in the treatment of cts. methods: during this single-blind randomized clinical trial, 65 hands with mild or moderate cts were divided randomly into two groups. one group received local corticosteroid injection (hydrocortisone 50 mg) and the other received low level laser therapy (20j/cm² in 11 seconds/session for each of 5 points, 775nm, 10 sessions and 3sessions/week). furthermore, wrist splints with extension degree of 0° (neutral position) were prescribed simultaneously for 6 weeks in each group.pain severity and electrodiagnostic measurements were compared from before to 10 months after completing each treatment. data were analyzed with spss 11.5 software and parametric tests. results:  generally, the mean age of patients was 43.9 years, duration of pain was 7.4 months, male to female ratio was 1:3, pain severity using visual analogue scale (vas) was 6.1 cm, and functional status measure was 15.5. the severity of the disease based on electrodiagnostic studies was 43.2% mild (41.2% in injection group and 45.2% in laser therapy group) and 56.8% moderate. the electrodiagnostic characteristics of the median nerve prior to treatment were included mean sensory peak latency of 4.3ms, mean sensory amplitude of 23.5μv, mean motor onset latency of 4.3ms and mean motor amplitude of 4.6mv. there was no meaningful difference between two groups regarding the demographic characteristics and electrodiagnostic measures (p>0.05). ten months after treatments, the mean of pain severity was decreased 1.9cm in injection group and 1.7cm in laser therapy group, the mean of median sensory peak latencies was decreased 0.4ms in injection group and 0.25ms in laser therapy group and the mean of motor onset latencies was decreased 0.15ms in both groups,with no significant difference between the observed treatments variables (p>0.05). the severity of disease based on electrodiagnostic studies became 32.4% normal,23.5% mild, 41.2% moderate and 2.9% severe in the injection group and 38.7% normal,22.6% mild, 35.5% moderate and 3.2% severe in the laser therapy group. there was no meaningful difference between two groups regarding the changes in the pain severity, functional status and electrodiagnostic measures. conclusion :   low level laser therapy can be as effective as local injection in reducing pain and severity of disease (based on electrodiagnostic medicine classification) in patients with mild and moderate cts even in long term (after 10 months).