DIAGNOSIS OF CARPAL TUNNEL SYNDROME: Ultrasound Versus Electromyography
Section snippets
EPIDEMIOLOGY AND ETIOLOGY
CTS is associated with a welter of illnesses and conditions:
Occupations
Typists
Transcriptionists
Musicians
Jackhammer operators
Factory workers
Carpenters
Needle workers
Conditions
Pregnancy
Rheumatoid arthritis
Chronic renal failure
Diabetes mellitus
Wrist trauma
Amyloidosis
Tumors
Ganglia
Tendinitis or tenosynovitis
It most commonly affects people involved in tasks that require repeated motions and stresses of the hand and wrist. Although chronic illnesses, such as rheumatoid arthritis and chronic renal
DIAGNOSIS
Clinical diagnosis of CTS involves physical examination and electromyography (EMG). Typically, a patient presents with a history of numbness or weakness in the median nerve distribution. The symptoms can vary from mild pain due to repetitive activity to night pain and severe weakness. On physical examination, positive Tinel's and Phalen's signs are often elicited.16, 19 Thenar muscle atrophy is usually a late finding, consistent with chronic CTS. Conservative treatments including vitamin B6,
MEDIAN NERVE
The median nerve is a long peripheral nerve that originates from the brachial plexus to enervate the distal muscles of the hand as well as other structures along its course. It traverses the carpal tunnel, which is located in the volar aspect of the wrist just distal to the wrist crease. The median nerve is a small structure, but because of its superficial location, it is ideally imaged using high-frequency linear-array transducers.
Although ultrasound imaging of the median nerve has been
THREE-PHASE DESIGN
This investigation was designed in three phases in order to clarify the carpal tunnel anatomy, elucidate the ultrasound characteristics of the median nerve and the carpal tunnel, develop an understanding of the ultrasound changes with pathology, and finally evaluate the potential of ultrasound as a diagnostic tool for CTS.
Phase 1 was devoted to understanding the normal median nerve anatomy and determining its ultrasound characteristics. This was accomplished by cadaver dissection of the wrist,
CONCLUSION
Ultrasound is a simple technique to evaluate the median nerve and the contents of the carpal tunnel. The anatomy of the median nerve can be clearly defined and accurate measurements of its dimensions can be obtained. The abnormalities of the nerve, including edema, contour deformities, and enlargement of its cross-sectional area, can also be determined by ultrasound. There is a high degree of correlation between the conduction abnormalities of the median nerve as detected by EMG and the
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Cited by (227)
The cross-sectional morphology of median nerve in carpal tunnel of healthy, adult population: A systematic review and meta-analysis
2023, MorphologieCitation Excerpt :Sometimes, MNCSA is reduced in polyneuropathy due to decreased myelin sheath thickness and impaired regeneration following neuronal degeneration. In such cases, MN-CSA may be within the normal limit [24,32,55–57,102]. The evaluation of echogenicity, FR, and circularity, will be helpful in such cases.
Idiopathic carpal tunnel syndrome (ICTS): Correlation between nerve conduction studies and dynamic wrist ultrasonography
2018, Egyptian Journal of Radiology and Nuclear MedicineIdentifying and Overcoming the Barriers to Virtual Electromyography Assessments: A Scoping Review
2024, Telemedicine and e-HealthEvaluation of the Effect of Age on Median Nerve Cross-sectional Area: A Cross-sectional Study
2023, Advanced Ultrasound in Diagnosis and Therapy
Address reprint requests to Doohi Lee, MD, Department of Radiology, Saint Mary's Hospital, 5801 Bremo Road, Richmond, VA 23226