By Michael Rubin, MD

Professor of Clinical Neurology, Weill Cornell Medical College

Dr. Rubin reports no financial relationships relevant to this field of study.

SYNOPSIS: Carpal tunnel syndrome can be reliably diagnosed, only with nerve conduction studies, and this test should be performed before any invasive treatments are initiated.

SOURCE: American Academy of Orthopaedic Surgeons. Management of Carpal Tunnel Syndrome: Evidence-Based Clinical Practice Guideline. www.aaos.org/ctsguideline. Published Feb. 29, 2016.

Based on a comprehensive review of current scientific and clinical information, the American Academy of Orthopedic Surgeons recently published an encyclopedic tome spanning 982 pages, outlining, in detail, new guidelines for the diagnosis, investigation, and treatment of carpal tunnel syndrome (CTS).

Body mass index and repetitive hand/wrist movements are risk factors strongly associated with CTS, whereas perimenopausal age, rheumatoid arthritis, gardening, and assembly line and computer work are some of the factors moderately associated with increased risk of CTS. Taken alone, age, gender, diabetes, bilaterality of symptoms, or worsening at night are weakly or poorly associated. Only a limited association was found between CTS and distal radial fracture or dialysis. Hormone replacement therapy and oral contraceptive use are not associated with CTS. Thenar muscle atrophy is the only clinical sign strongly associated with CTS, but its absence does not rule it out. All other physical signs and maneuvers, taken alone, are poor or weak indicators of CTS, including the Phalen or reverse Phalen sign, Tinel sign, thenar weakness, Luthy sign (where, due to thumb abduction weakness, the skinfold between the thumb and index finger does not wrap tightly around a cup), or flick maneuver (where patients vigorously shake their hand or hands, and symptoms of suspected CTS resolve immediately, or shortly thereafter).

Apart from obtaining a history and performing a physical examination, standard nerve conduction studies are the only recommended test for diagnosis. Ultrasound and magnetic resonance imaging of the wrist are not routinely recommended.

Strong evidence indicates that splinting the wrist and methylprednisolone injections are beneficial, whereas magnetic therapy is not. Nonsteroidal anti-inflammatory agents, diuretics, gabapentin, and pyridoxine appear to be no better than placebo, but oral steroids and ketoprofen phonophoresis show benefit. Compared to placebo, therapeutic ultrasound and laser therapy can be effective, but surgical release shows the strongest evidence of benefit at 6 and 12 months compared to nonoperative approaches, with endoscopic carpal tunnel release possibly showing additional short-term benefits in terms of earlier pain relief and earlier return to work. Other than carpal ligament release, no additional benefit appears to accrue from additional neurolysis, tenosynovectomy, epineurotomy, or ligament-lengthening procedures. Local anesthesia is preferred over intravenous regional anesthesia, due to longer postoperative pain relief. Buffered rather than plain lidocaine is the preferred anesthetic, due to less injection pain. Aspirin may be continued perioperatively. Routine preoperative antibiotics, supervised physical therapy, and postoperative immobilization appear to be of no benefit.

COMMENTARY

Surprisingly, pregnancy and its association with CTS were not mentioned in this guideline. Among 639 pregnant women, 34% (n = 219) reported symptoms of CTS. Even after adjusting for age, body mass index, depression scores and parity, CTS was significantly associated with higher levels of fluid retention compared to those who did not report CTS symptomatology, and, during the third trimester, had an independent negative effect on sleep.1 Although CTS is found in 4% of the general population, it is nine times higher in pregnancy. Vitamin D deficiency was also omitted. It is significantly more common in patients with CTS, compared to normal controls, and although lower vitamin D levels do not correlate with symptom severity, functional status, or pain score, patients with CTS should have their vitamin D levels measured and normalized where appropriate.2

REFERENCES

  1. Meems M, Truijens S, Spek V, et al. Prevalence, course and determinants of carpal tunnel syndrome symptoms during pregnancy: A prospective study. BJOG 2015;122:1112-1118.
  2. Gursoy AE, Bilgen HR, Duruven H, et al. The evaluation of vitamin D levels in patients with carpal tunnel syndrome. Neurol Sci 2016; Mar 3 [Epub ahead of print]. Doi: 10.1007/s10072-016-2530-0.