Evidence in Preoperative Management

Diagnosis The classic history is of the patient who begins his or her symptoms by awakening at night with numbness and pain in the median nerve distribution of his or her hand(s). This progresses to daytime symptoms that are often aggravated by activities.1,2 The occurrence of “dropping objects” in carpal tunnel syndrome patients is an index of elevated disease severity.3 Carpal tunnel symptoms in pregnancy persist in more than 50 percent of the patients after 1 year and in approximately 30 percent after 3 years.4 The highest sensitivity and specificity on physical examination are found with the wrist flexion-carpal compression examination (82 and 99 percent, respectively) (Fig. 1) and the Durkan carpal compression test (87 and 90 percent, respectively) (Fig. 2).5 In a study comparing the scratch collapse test, the Tinel test, and the wrist flexion/compression test in carpal tunnel syndrome, sensitivities were 64, 32, and 44 percent, respectively (Level of Evidence: Diagnostic, II).6 The scratch collapse test had the highest negative predictive value (73 percent) for carpal tunnel syndrome. The scratch collapse test had significantly higher sensitivity than the Tinel test and the flexion/nerve compression test. Nerve conduction studies have a sensitivity ranging from 73 to 100 percent but a specificity of 97.5 percent.7 A recent review comparing nerve conduction studies with ultrasound, computed tomography, and magnetic resonance imaging concluded that the nerve conduction study remains the criterion standard8 preoperative investigation. However, a negative nerve conduction study does not mean a patient does not have carpal tunnel syndrome that will respond to surgery. Concannon et al. retrospectively reviewed a large series of patients who responded to surgery