Emergency Department Care
In the emergency department setting, the mainstay of treatment for carpal tunnel syndrome (CTS) is rest, wrist immobilization with a splint, and nonsteroidal anti-inflammatory drugs (NSAIDs). For some individuals with CTS, nonsurgical management is curative; however, more than 50% of patients undergoing nonsurgical management progress to surgery within 1 year. [15]
A volar splint should be placed in neutral position because flexion and extension of the wrist increases carpal intracanal pressure. Splinting has been shown to have a statistically significant decrease in symptoms compared with controls. Studies comparing nocturnal-only splinting to full-time splinting have not revealed a clear difference, although the studies may have been underpowered. [32, 33, 34]
No data support that NSAIDs are superior to placebo in the treatment of CTS. [33] However, in the absence of contraindications, a trial of NSAIDs may be appropriate.
Oral steroids have been shown to have an advantage in treating CTS over placebo. The benefit appears short-lived, and the studies do not assess the long-term effectiveness or complications of oral steroids used in treating CTS. [32, 33]
Although not typically performed in the emergency department, corticosteroid injections have been shown to have a statistically significant benefit in CTS at 1 month compared with placebo. The effects of corticosteroid injection appear to be time limited, and the benefit beyond 1 month is unclear. Two steroid injections do not appear to add significant clinical benefit to one injection. [35, 36] Local injections have been shown to be superior to systemic corticosteroids. [32] Steroid injection combined with splinting has been shown to be superior to splinting alone. [37] Single corticosteroid injection has been shown to be superior to night splinting at 6 months. [38] Ultrasound-guided injections have been shown to be more effective than blind injections. [39]
Diuretics have not been shown to be superior to placebo in the treatment of CTS. [33]
Ultrasound has been proposed as a treatment for carpal tunnel syndrome, though evidence is conflicting. A recent randomized controlled trial showed no benefit for therapeutic ultrasound, while a systematic review of extracorporeal shockwave therapy showed improvement in symptoms, function, and electrodiagnostic study results when to corticosteroid injection. [40, 41] Evidence is limited for newer modalities such as manual techniques, transcutaneous electrical nerve stimulation (TENS), and laser therapy [42] .
Surgery
Definitive therapy consists of surgical release of the transverse carpal ligament. Surgery for CTS has a long-term success rate of greater than 75%. The surgical approach may be open or endoscopic. [43] A randomized, controlled trial showed that patients who underwent endoscopic surgery for carpal tunnel syndrome had less postoperative pain than patients who underwent open surgery; however, the difference was small. [44] The authors of this study extended the follow-up period to 5 years, and it demonstrated an equivalent improvement in CTS symptoms between an open and an endoscopic carpal tunnel release. An article in the Cochrane Database of Systematic Reviews states that endoscopic surgery allows an earlier return to work and fewer wound problems, but possible disadvantages may be higher complication rates and cost. [33, 34, 35, 45, 46]
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Carpal tunnel syndrome. Carpal and Guyon tunnels. Drawing showing the proximal level of the carpal tunnel delimited by the pisiform (P) and the scaphoid (S). The flexor retinaculum (medium gray region) forms the roof of the carpal tunnel and the floor of the Guyon tunnel. The palmar carpal ligament (dark gray region) forms the volar boundary of the Guyon tunnel. * = flexor pollicis longus tendon, * = flexor carpi radialis tendon. From Martinoli C, Bianchi S, et al. US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs. Radiographics 2000; 20:S199-S217. Used by permission of the authors and RSNA.
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Carpal tunnel syndrome. Carpal and Guyon tunnels. Transverse 5-12-MHz ultrasound scan corresponding to the image above shows the proximal level of the carpal tunnel delimited by the pisiform (P) and the scaphoid (S). The flexor tendons and median nerve (MN) extend through the carpal tunnel, with the nerve lying palmar and radial. The flexor retinaculum (open arrowheads) forms the roof of the carpal tunnel and the floor of the Guyon tunnel. At the level of the pisiform, the ulnar nerve (U) courses medial to the ulnar artery (solid arrowhead) within the Guyon tunnel. * = flexor pollicis longus tendon. From Martinoli C, Bianchi S, et al. US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs. Radiographics 2000; 20:S199-S217. Used by permission of the authors and RSNA.
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Carpal tunnel syndrome. Carpal and Guyon tunnels. Drawing showing the distal level of the carpal tunnel delimited by the hook of the hamate (H) and the tubercle of the trapezium (T). The flexor retinaculum (medium gray region) forms the roof of the carpal tunnel. From Martinoli C, Bianchi S, et al. US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs. Radiographics 2000; 20:S199-S217. Used by permission of the authors and RSNA.
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Carpal tunnel syndrome. Carpal and Guyon tunnels. Transverse 5-12-MHz ultrasound scan corresponding to the image above shows the distal level of the carpal tunnel delimited by the hook of the hamate (H) and the tubercle of the trapezium (T). The flexor retinaculum (open arrowheads) forms the roof of the carpal tunnel. The flexor tendons and median nerve (MN) extend through the carpal tunnel, with the nerve lying palmar and radial. At the level of the pisiform, the ulnar nerve courses medial to the ulnar artery (solid arrowhead) within the Guyon tunnel. At the level of the hamate, the ulnar nerve divides into two terminal branches, a deep motor branch (curved arrow) and a superficial sensory branch (straight arrow). From Martinoli C, Bianchi S, et al. US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs. * = flexor pollicis longus tendon. Radiographics 2000; 20:S199-S217. Used by permission of the authors and RSNA.
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Carpal tunnel syndrome. Normal findings on an axial spin-echo T1 MRI of the carpal tunnel showing the intermediate signal intensity of the median nerve (arrow).
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Carpal tunnel syndrome. Normal findings of isointense-to-hypointense appearance of the median nerve on fast spin-echo T2-weighted MRI (arrow). Note the fairly well-defined nerve fascicles within the median nerve sheath.
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Carpal tunnel syndrome. Axial fast spin-echo T2-weighted MRI with fat saturation. Note the increased T2-weighted signal within the median nerve (arrow). A slightly increased cross sectional area of the nerve is noted but the nerve architecture is preserved, consistent with early or mild inflammation.
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Carpal tunnel syndrome. Fast spin-echo T2-weighted MRI illustrates more pronounced increased signal within the median nerve (arrow). Note the small amount of fluid within the carpal tunnel, a secondary sign of inflammation. Slightly less optimal fat saturation is noted than on other images, which is a common occurrence.
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Carpal tunnel syndrome. Axial fast spin-echo T2-weighted MRI with greater increase in signal and loss of definition within the nerve (arrow). Inflammatory change is noted within the carpal tunnel, adjacent to the flexor digitorum superficialis tendons. The appearance is consistent with pronounced inflammatory change within the carpal tunnel.
