Thus, AAOS does not currently recommend ultrasound for CTS diagnosis.7 Magnetic resonance imaging is inappropriate for routine CTS diagnosis, as well.7
Treatment: Start conservatively
Multiple nonsurgical options are available, but the best evidence supports splinting, steroid injection, and oral steroids. Splinting or steroids alone may bring long-term relief for patients with mild to moderate cases;20 in fact, about a third of mild cases improve spontaneously.21
Conservative therapy can also provide relief for those who wish to avoid or delay surgery and for cases of transient CTS (pediatric patients, for example, or those whose condition is associated with pregnancy or hypothyroidism).18 A successful response to therapy can also help to confirm a CTS diagnosis.
Most conservative treatments begin providing relief within 2 to 6 weeks and reach the maximal benefit at 3 months.22 If there is no response after 6 weeks, it’s time to consider another approach.
In initiating splinting or corticosteroids, here’s a look at what to keep in mind:
Splinting. A splint can be used to maintain the wrist in a position with the least intracanal pressure, thereby limiting pressure on the median nerve. Splinting is equally effective whether used continually or only at night.23
Splinting can relieve symptoms and improve functional status within 2 weeks and the effects can last for 3 to 6 months, eliminating the need for surgery for some patients with mild CTS.19,20 Nerve gliding exercises, (see image at left), have been evaluated in combination with splinting. While evidence is limited, an at-home program involving these simple exercises may be a beneficial adjunctive treatment with minimal cost or harm.24,25
Local corticosteroid injection. A Cochrane meta-analysis found significant improvement in symptoms and function at one month among patients with CTS who were treated with steroid injection.26 In many cases, the effects last for many months.
A recent trial found that nearly half of patients with mild to moderate CTS who were treated with steroid injections had improved symptoms and EDS results at the 12-month follow-up.20 However, while patients with severe CTS experienced improvement at 4 weeks postinjection, most eventually required surgery.20
Evidence does not support one particular steroid dose or formulation over another, or one particular injection site.22 Injecting 4 cm proximal to the wrist flexion crease is as effective as a more distal injection.26,27
Caution is required, however, as risks associated with local injections include tendon rupture and median nerve injury. If a patient experiences intense pain or paresthesia in the median nerve distribution when the needle is inserted, redirect the needle away from the median nerve immediately. For patients who respond well to this treatment, one additional injection can be given after 6 months if symptoms recur.
Oral corticosteroids. Oral prednisone at a dose of 20 mg/d for 2 weeks improves symptoms and function in patients with CTS, but is less effective than steroid injections.28 Treatment for 2 weeks is as effective as treatment for 4 weeks; the effects tend to wane after 8 weeks in both cases.29 Nonsteroidal anti-inflammatory drugs, diuretics, and vitamin B6 have not been found to be effective.30
CASE Ms. K also asks about “those needle tests”—a reference to EDS—which her sister had to diagnose her CTS. You explain that these studies are not necessary at this time because her symptoms are mild and there is no need for other causes to be ruled out.
Instead, you offer her a neutral wrist splint for night-time use and recommend home-based nerve glide exercises. There is no evidence that cold laser therapy is effective, you explain to Ms. K, and it is expensive. She agrees to try the splint and the exercises, and you schedule a follow-up visit in 6 weeks.
A look at alternative therapies
There are many nontraditional treatments for CTS, with yoga, carpal bone mobilization, ergonomic keyboards, and ultrasound therapy among them. Some have limited evidence to suggest that they may have a therapeutic effect;30 others have little or no evidence to support them.
Yoga. Stretching and improved joint posture with specific yoga exercises may lead to decreased compression within the carpal tunnel and increased blood flow to the median nerve. One small study found that yoga was more effective than nocturnal wrist splinting for pain relief, and had similar improvement for nocturnal symptoms and grip strength.31
Carpal bone mobilization. One small study found this physical therapy technique, which involves movement of the bones in the wrist, to improve symptoms such as numbness and tingling after 3 weeks of therapy. Yet carpal bone mobilization did not relieve pain or help restore function.32