d Review DIAGNOSTIC ACCURACY OF ULTRASONOGRAPHY VS. ELECTROMYOGRAPHY IN CARPAL TUNNEL SYNDROME: A SYSTEMATIC REVIEW OF LITERATURE SHAWN C. ROLL,J ANE CASE-SMITH, and KEVIN D. EVANS The Ohio State University, College of Medicine, Columbus, OH, USA (Received 26 January 2011; revised 29 May 2011; in final form 21 June 2011) Abstract—A plethora of research investigates sonography vs. electrodiagnostic testing (EDX) for diagnosis of carpal tunnel syndrome (CTS). Through database searches, hand searches and communication with authors, 582 abstracts published from 1999 to 2009 were identified. A comprehensive systematic review process resulted in inclusion of 23 studies. Significant methodologic discrepancies among the studies limited the ability to complete a meta-analysis to identify specific diagnostic thresholds. Instead, the data were reviewed to provide implications for clinical utility of sonography as a screening tool as a compliment to EDX and to suggest continued and future research. The largest cross-sectional area of the median nerve within the carpal tunnel region has high potential for clinical screening, especially in individuals with severe CTS. Identifying swelling of the nerve through comparative measurements, qualitative analysis and Doppler techniques all require further investigation. Screening protocols may be enhanced through exploration of sonography in patients with mild CTS and false-negative EDX. (E-mail: evans.36@osu.edu) Ó 2011 World Federation for Ultrasound in Medicine & Biology. Key Words: Median nerve mononeuropathy, Carpal tunnel syndrome, Musculoskeletal, Diagnostics, Ultrasonog- raphy, Nerve conduction study. INTRODUCTION Carpal tunnel syndrome (CTS) is characterized by motor, sensory and autonomic nerve impairment resulting in numbness and tingling in the median nerve distribution of the hand, hypotrophy of the thenar musculature, drop- ping of items and decreased sweat function in the hand, with symptom exacerbation at night and after frequent or repetitive use of the wrist and hand (Kuhlman and Hennessey 1997; MacDermid and Doherty 2004; Marklin 1999; Marx et al. 1998; Rempel et al. 1998). Historically, clinical diagnosis of CTS is reliant upon a combination of these patient reported symptoms with positive clinical provocative tests and positive electrodiagnostic (EDX) results (Karadag et al. 2010; Rempel et al. 1998). Positive predictive values and overall sensitivity and specificity have been generally poor for provocative tests (Kuhlman and Hennessey 1997; Mondelli et al. 2001). Furthermore, while specificity may be high for EDX testing, significant variability in sensitivity and moderate rates of false-negatives exist (Jablecki et al. 2002; Lew et al. 2005). In response to the variability of these tests, new methods continue to be developed and tested. Of these new methods, sonography has gained traction as a possible tool for use in clinical evaluation and research in median nerve pathology. Because sonography is pain-free, relatively inexpensive, allows for dynamic evaluation and is becoming more portable, this tool is perfectly situated as a diagnostic tool for musculoskeletal and neurological impairments (Kurca et al. 2008; Roll and Evans 2009). Researchers have investigated the diagnostic ability of sonography for carpal tunnel syndrome; unfortunately, similar to provocative tests and EDX, each of the sonographic techniques and tools suggested for diagnosing CTS varies in utility and quality criteria. Therefore, diagnostic measures remain controversial (El Miedany et al. 2008) and stan- dard measurement techniques have not been determined (Hobson-Webb and Padua 2009). As the use of sonography for evaluation of the median nerve in CTS increases, periodic syntheses of the research evidence can provide direction to research Address correspondence to: Kevin D. Evans, Ph.D., The Ohio State University, School of Allied Medical Professions, 435 W. 10th Avenue, 340 Atwell Hall, Columbus, OH 43210, USA. E-mail: evans. 36@osu.edu 1539 Ultrasound in Med. & Biol., Vol. 37, No. 10, pp. 1539–1553, 2011 Copyright Ó 2011 World Federation for Ultrasound in Medicine & Biology Printed in the USA. All rights reserved 0301-5629/$ - see front matter doi:10.1016/j.ultrasmedbio.2011.06.011