Carpal Tunnel Syndrome
Symptoms and Diagnosis
The primary symptoms of CTS are pain, numbness, and tingling in the wrist and first three fingers of the affected hand (LeBlanc 2011; Haase 2007). Pain can also occur in the palm of the hand or in the forearm (LeBlanc 2011). Hand or wrist weakness may also be present. Symptoms involving the hands are often worse during work or at night (Haase 2007). Severe cases of CTS may be associated with visible loss of muscle mass in the hands and/or loss of ability to distinguish touch between two nearby areas of the hand (two-point discrimination) (LeBlanc 2011; Haase 2007; Kilot 2013).
Diagnostic physical exam tests include Tinel’s sign (a tingling sensation elicited by tapping over the carpal tunnel) and/or a positive Phalen’s maneuver (reproduction of symptoms, usually numbness and tingling, when the wrist is flexed) (LeBlanc 2011; Haase 2007; Szabo 1999). The “flick” signal can be a telltale sign of CTS as well; if symptomatic relief can be attained by shaking or flicking the wrist in a manner similar to shaking a thermometer, then CTS may be the cause of the symptoms (Simon 2012).
CTS can be clinically diagnosed on the basis of medical history and physical examination (LeBlanc 2011; Haase 2007; Kilot 2013), but objective testing measures such as nerve conduction studies, electromyography, and diagnostic ultrasound are commonly used as well. Nerve conduction tests are meant to detect delayed median nerve conduction rates, a diagnostic sign for CTS (LeBlanc 2011; Haase 2007). Ultrasound of the wrist joint, carpal tunnel, and median nerve can be used for CTS diagnosis (Bickel 2010; Hammer 2006; Hammer 2007), and one author suggested that ultrasound is as accurate but less expensive than nerve conduction studies (McDonagh 2014). Imaging techniques such as MRI (magnetic resonance imaging) or MRI-DTI (MRI-diffusion tensor imaging), CT (computed tomography), or X-rays may be diagnostically useful in cases involving wrist trauma, congenital abnormalities, or masses (eg, tumors) (Alfonso 2010; Haase 2007; Yildirim 2014).