What are the effects of drug treatment?
LIKELY TO BE BENEFICIAL
Two small randomized controlled trials (RCTs) identified by a systematic review and one subsequent RCT showed that oral prednisone improved symptoms after two weeks compared with placebo. Two of the three RCTs showed that the improvement was maintained at four to eight weeks. We found no systematic review or RCT that measured longer-term effects of oral corticosteroids on symptoms. One small RCT identified by a systematic review showed no significant difference in symptoms at two weeks between local methylprednisolone injection and oral prednisone. However, local methylprednisolone injection improved symptoms after eight and 12 weeks. Another small RCT identified by the same systematic review showed that betamethasone injected into the deltoid was less effective at improving symptoms after one month compared with local betamethasone injection. One RCT showed that oral prednisone reduced symptoms compared with a nonsteroidal anti-inflammatory drug (NSAID; tenoxicam) and with a diuretic (trichlormethiazide) after four weeks.
Corticosteroid (Local Injection)
Two small RCTs showed that local corticosteroid injection (methylprednisolone, hydrocortisone) improved symptoms after four to six weeks compared with placebo or no treatment. One small RCT showed that local betamethasone injection improved symptoms after one month compared with betamethasone injection into the deltoid. One small RCT showed no significant difference in symptoms between local injection and oral prednisone after two weeks, but it showed that local methylprednisolone injection improved symptoms after eight and 12 weeks.
UNLIKELY TO BE BENEFICIAL
Two small RCTs showed no significant difference in symptoms between diuretics and placebo after two and four weeks. One of the RCTs showed no significant difference in symptoms between a diuretic (trichlormethiazide) and an NSAID (tenoxicam) at four weeks, and it showed that trichlormethiazide was less effective than oral prednisone at reducing symptoms after four weeks.
One RCT identified by a systematic review showed no significant difference between an NSAID (tenoxicam) and placebo or a diuretic (trichlormethiazide) at two or four weeks. The RCT showed that tenoxicam was less effective than oral prednisone after four weeks.
One small RCT showed similar symptom improvement between pyridoxine and placebo or no treatment after 10 weeks. The RCT may have been too small to detect a clinically important difference between treatments. One small RCT showed no significant difference between pyridoxine and placebo in nocturnal pain, numbness, or tingling after 12 weeks.
What are the effects of nondrug treatment?
One RCT showed that a nocturnal hand brace improved symptoms after two and four weeks compared with no treatment. One small RCT showed no significant difference in symptoms between neutral angle and 20-degree extension wrist splinting after two weeks. One small RCT showed no significant difference in symptoms between full-time and nighttime-only neutral angle wrist splinting at six weeks.
Nerve and Tendon Gliding Exercises
One small RCT showed no significant difference in symptom severity or function between four weeks of nerve and tendon gliding exercises plus neutral angle wrist splinting and neutral angle wrist splinting alone after eight weeks.
One RCT showed that ultrasonography increased satisfactory improvement in the wrist or complete remission of symptoms after six months compared with placebo. One RCT showed no significant difference in symptom severity between high- and low-intensity ultrasonography compared with placebo after two weeks.
What are the effects of surgical treatment?
UNLIKELY TO BE BENEFICIAL
Open Carpal Tunnel Release Plus Internal Neurolysis
RCTs identified by a systematic review showed no significant difference in symptoms between open carpal tunnel release alone and open carpal tunnel release plus internal neurolysis.
TRADE-OFF BETWEEN BENEFITS AND HARMS
Endoscopic vs. Open Carpal Tunnel Release
One systematic review and subsequent RCTs showed no consistent difference in symptoms up to 12 months after surgery or time to return to work between endoscopic and open carpal tunnel release. Harms from endoscopic and open carpal tunnel release vary among RCTs. One systematic review and two RCTs comparing the interventions suggested that endoscopic carpal tunnel release may cause more transient nerve problems, whereas open carpal tunnel release may cause more wound problems.
Surgery vs. Placebo or Nonsurgical Intervention
We found no RCTs comparing surgery with placebo. One small RCT identified by a systematic review and one subsequent RCT showed that surgery increased symptom resolution compared with splinting for up to 18 months.
What are the effects of postoperative treatment?
LIKELY TO BE INEFFECTIVE OR HARMFUL
Wrist Splinting After Carpal Tunnel Release
Two RCTs including patients who had carpal tunnel release surgery showed no significant difference between wrist splinting and no splinting in grip strength or in the proportion of persons who considered themselves “cured” at two to four weeks. A third RCT showed that splinting increased pain at one month and increased time to return to work compared with no splinting.
Carpal tunnel syndrome is a neuropathy caused by compression of the median nerve within the carpal tunnel.1 Classic symptoms of carpal tunnel syndrome include numbness, tingling, burning, or pain in at least two of the three digits supplied by the median nerve (i.e., thumb, index finger, and middle finger).2 The American Academy of Neurology has described diagnostic criteria for carpal tunnel syndrome that rely on a combination of symptoms and physical examination findings.3 Other diagnostic criteria include results from electrophysiologic studies.2
Incidence and Prevalence
A general population survey in Rochester, Minn., showed the age-adjusted incidence of carpal tunnel syndrome to be 105 cases per 100,000 person-years (95% confidence interval [CI], 99 to 112).4,5 Age-adjusted incidence rates were 52 cases per 100,000 person-years (95% CI, 45 to 59) for men and 149 cases per 100,000 person-years (95% CI, 138 to 159) for women. The study showed that the incidence increased from 88 cases per 100,000 person-years (95% CI, 75 to 101) between 1961 and 1965 to 125 cases per 100,000 person-years (95% CI, 112 to 138) between 1976 and 1980. The incidence increased with age in men, whereas it peaked at 45 to 54 years of age in women.
A general population survey in the Netherlands showed the prevalence of carpal tunnel syndrome to be 1 percent in men and 7 percent in women.6 A more comprehensive study in southern Sweden showed the prevalence to be 3 percent (95% CI, 2 to 3) in the general population.7 As in other studies, the overall prevalence was higher in women than in men (male-to-female ratio of 1.0:1.4). However, among older persons, the prevalence in women was over three times that in men (age group 65 to 74 years; men, 1.7 percent [95% CI, 0.5 to 4.3]; women, 5.4 percent [95% CI, 3.1 to 8.8]).
Most cases of carpal tunnel syndrome have no easily identifiable cause (idiopathic).4 Secondary causes of carpal tunnel syndrome include space-occupying lesions (tumors, hypertrophic synovial tissue, fracture callus, osteophytes); metabolic and physiologic causes (pregnancy, hypothyroidism, rheumatoid arthritis); infection; neuropathies (associated with diabetes mellitus or alcoholism); and familial disorders.4 One case-control study showed that risk factors in the general population include repetitive activities requiring wrist extension or flexion, obesity, very rapid dieting, shorter height, hysterectomy without oophorectomy, and recent menopause.8
One observational study (carpal tunnel syndrome was defined by symptoms and electrophysiologic study results) showed that 34 percent of persons with untreated idiopathic carpal tunnel syndrome had complete resolution of symptoms (remission) within six months of diagnosis.9 Remission rates were higher in younger age groups, in women, and during pregnancy. A more recent observational study of untreated idiopathic carpal tunnel syndrome also showed that symptoms may spontaneously resolve in some persons. The main positive prognostic indicators were short duration of symptoms and young age, whereas bilateral symptoms and a positive Phalen's maneuver were indicators of a poorer prognosis.10