Loving our phones, laptops and other digital devices is wreaking havoc on our well-being. From swiping on social media, texts, emails and more, the repetitive movements of hands and wrists are creating an epidemic of people with Carpal Tunnel Syndrome.
In 2018, about 165 million cell phones and 205 million laptops were purchased in the U.S. By 2020 the estimated number of new cell phones will exceed 2.5 billion.
With over 8 million Americans impacted by Carpal Tunnel Syndrome annually, the U.S. Department of Labor has concluded “Carpal Tunnel Syndrome is the chief occupational hazard” in the U.S. and is now disabling people in epic proportions.
It’s no surprise that patients seeking wrist and hand pain relief is on the rise among physical therapy practices. But diagnosing wrist and hand pain can be tricky.
Author and Doctor Beshoy Ghaly offers an article and study here.
THE USE OF ELECTRODIAGNOSTIC STUDIES AND MUSCULOSKELETAL SONOGRAPHY IN CARPAL TUNNEL SYNDROME
By Beshoy Ghaly, HODS Partner
Carpal tunnel syndrome is the number one reason for referral to Electrodiagnostic practices and can be considered as the most common peripheral focal mononeuropathy.1, 2 Carpal tunnel syndrome is simply an injury to the median nerve at the wrist where the nerve can face a potential entrapment in the tunnel that is formed by the carpal bones. Differential diagnosis of carpal tunnel syndrome from C6-C7 radiculopathy and, less often, brachial plexus injuries may be challenging particularly in very mild or early cases.1
According to CPG on CTS adopted by American Academy of Orthopaedic Surgeons (AAOS), there is no one gold standard test to diagnose CTS.3 Using nerve conduction studies (NCS),electromyography (EMG) and neuroultrasound will offer the best combination of tests that help in diagnosing and classifying the severity of the condition. Para-nodal demyelination of the median nerve at the wrist is the early underlying pathology in CTS.2 Focal slowing across the wrist and increased distal latencies of sensory and motor portions are common.2 Reduced amplitude of the median sensory nerve action potential (SNAP) at the wrist compared to the palm can be the only early sign in CTS cases implying a possible conduction block and myelin sheath compromise.4 Assessing the electrical stability of the membrane of Abductor pollicis brevis muscle using needle EMG helps identifying moderate to severe cases where possible axonal loss of the median nerve may occur. (Figure1) Quantifying the percentage of possible axonal loss may be obtained by comparing the compound muscle action potential (CMAP) of the affected nerve to the unaffected opposite nerve.
A reasonable scheme, out of many, to be considered when it comes to classifying the severity of the syndrome is GEHS neurophysiological system.5 Prolonged sensory latencies, present sensory response, and normal motor latencies are considered a mild injury.4, 5 Add to the previous prolonged motor latencies will be considered as a moderate injury.4, 5 Reduced motor amplitudes and/or signs of axonal loss and denervation on EMG can be considered as a severe injury.4, 5
In general, Electrophysiologic evaluation should be focused toward showing the focal neuropathy or the conduction block of the median nerve at the wrist, ruling out the rare proximal median nerve injury and excluding brachial plexus and cervical radiculopathy injuries.1
The AAOS CPG rates NCS 2 out of 4 and all physical signs combined (Phalen’s, Tinel’s etc.) as 4 out of 4.3 American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) CPG for NCS/ EMG mentioned that specific NCS methods are “valid and reproducible clinical laboratory studies”8 and“confirm a clinical diagnosis of CTS with a high degree of sensitivity (>85%) and specificity (95%).”8
Using neuro ultrasound, one can visualize and measure the diameter of the median nerve at the carpal tunnel. Swelling of the median nerve and loss of the honey comb appearance on the ultrasound image indicate possible positive findings toward diagnosing the syndrome.
Measuring the size of the median nerve, the vast majority of the studies suggest a cutoff of 0.09 to 0.12 cm2 as a sign of a carpal tunnel syndrome. 6 (Figure 2) Measuring the median nerve at the carpal tunnel area and comparing it to the pronator quadratus area can be of a great value. A difference of median nerve area of more than 2mm2 may diagnose the syndrome with an accuracy of 99%.6(Figure 2 and 3)
The validity and a reliability of the test are accepted and recommended by the CPG adopted by AAOS and were given 2 out of 4.3 The American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) issued an evidence based guideline for MSKUS diagnosing CTS.7 Recommendation1 is “neuromuscular ultrasound measurement of median nerve cross-sectional area at the wrist may be offered as an accurate diagnostic test for CTS (Level A)”7 and it was based on consistent class 1 and 2 evidence.
Finally, using diagnostic tools such as nerve conduction studies, electromyography, and neuro ultrasound help the diagnostician to accurately identify and classify the carpal tunnel syndrome. One study in AANEM CPG for CTS MSKUS showed 100% sensitivity and 92.5% specificity when combining neuro ultrasound and NCS/EMG in diagnosing CTS.7 Proper diagnosis, understanding, and analysis of a medical condition can lead to a proper management and hence a better patient care can be achieved.
Read entire study with photos in our free digital copy here: PTMadeEasy.com
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Here’s To Your Continued Success,
Dimitrios Kostopoulos, DPT, MD, PhD, DSc, ECS
ABPTS Board Certified in EMG/NCS Testing Clinical Affiliate Assistant Professor FAU College of Medicine www.DiagnosticsforPT.com #futureofpt
PS If you would like to offer patients a much more accurate diagnosis while dramatically increasing your revenues, schedule a free strategy session: http://HODSMeeting.com
1. Preston, D. and Shapiro, B. (2013). Electromyography and neuromuscular
disorders. London: Elsevier Saunders.
2. Katirji, B. (2007). Electromyography in clinical practice. Philadelphia: Mosby
3. Management of Carpal Tunnel Syndrome Evidence-Based Clinical Practice
Guideline American Academy of Orthopaedic Surgeons Website. http:// www.
aaos.org/ ctsguideline. Published February 22, 2016, Accessed February 26,
4. Tan, F. (2004). EMG secrets. Philadelphia, Pa.: Hanley & Belfus. 5. Greathouse D, Ernst G, Halle J, Shaffer S. GEHS Neurophysiological
Classification System for Patients with Carpal Tunnel Syndrome. U.S. Army
Medical Department Journal [serial online]. January 2016;60-67. Available from:
Academic Search Index, Ipswich, MA. Accessed August 15, 2017.
6. Jacobson, J. (2013). Fundamentals of musculoskeletal ultrasound. Philadelphia, PA: Elsevier/Saunders.
7. Evidence-Based Guideline: Neuromuscular Ultrasound for the Diagnosis of
Carpal Tunnel Syndrome. American Association of Neuromuscular and Electrodiagnostic Medicine Website. http://www.aanem.org/getmedia/ 1a029bcf- 81df-48d4-839a-f0bdda6128f4/NMUS-for-DX-of-CTS-for-web.pdf. Published
March 2012, Accessed February 19, 2017.
8. Practice Parameter for Electrodiagnostic Studies in Carpal Tunnel Syndrome:
Summary Statement (includes literature review). American Association of Neuromuscular and Electrodiagnostic Medicine Website. http://www.aanem.org/getmedia/df604eb2-1bbe-4cf8-a256- cc62f9128e5d/CTS_Reaffirmed.pdf. Published June 2002, Accessed February
Figure 1: Positive sharp waves and fibrillation potentials detected by needle
EMG marking electrical instability of the membrane of the abductor pollicis brevis
muscle and possible denervation process.
Figure 2: Loss of the honey comb appearance of the median nerve at the wrist
and significant increase of the nerve diameter to reach up to 0.46 cm2
Figure 3: Median nerve at the area of the pronator quadratus. The image was
taken for the same patient in figure 2. Significant reduction of the nerve diameter
that is clearly more than 2mm2 difference.