PracticeUpdate Neurology Best of 2018

CONFERENCE COVERAGE 24

15th International Congress on Neuromuscular Diseases

6–10 JULY 2018 • VIENNA, AUSTRIA By the PracticeUpdate Editorial Team

© TIRZA/www.tirza.at

Ultrasonography Valuable in Confirmation of Carpal Tunnel Syndrome Ultrasonography is an effective, sensitive and less expensive alternative to

In sex-matched controls (37 cases; 75 hands, n=39 female, n=6 male), mean dis- tal cross-sectional area was 0.79 ± 0.13 cm 2 (0.59 to 0.11 cm 2 ) and 0.77 ± 0.1 cm 2 (0.53 to 0.1 cm 2 ) in the right and left median nerves, respectively. Mean cross-sectional area of participants was significantly higher than in controls. Nerve conduction studies in 27 participants revealed absent evoked motor response in four individuals (n=3 right, n=1 left). In 24 cases, mean distal motor latency and com- pound muscle action potential of the right median nerve was 5.8 ± 1.4 (4.2 to 11.4) s and 8.65 ± 3.0 (3.3 to 10.3) mV, respectively. On the left (26 cases), it was 5.5 ± 1.8 (3.3 to 10.3) s and 8.3 ± 3.7 (0.6 to 15.8) mV, respectively. Median nerve sensory nerve action poten- tials were absent in 16 participants (n=10 bilateral, n=4 right, n=2 left). Mean sensory latencies were 4.5 ± 2.4 (2.5 to 12) s and 3.4 ± 0.7 (2 to 4) s in the right (n=13) and left (n=14) sides, respectively. Corresponding mean sensory amplitudes were:

MRI to confirm carpal tunnel syndrome. U ltrasonography has been found to be valuable for confirming carpal tunnel syndrome, suggest outcomes from two prospective studies reported at ICNMD 2018. Atchayaram Nalini, MD, of the National Insti- tute of Mental Health and Neurosciences in Bengaluru, India, explained that carpal tunnel syndrome is the most common entrapment neuropathy (prevalence 3.8%). Ultrasono- graphic measurements are sufficiently accurate in the diagnosis of carpal tunnel syndrome, allow differential diagnosis, and support the surgeon. Dr. Nalini and colleagues compared the sensitivity of electrodiagnosis and high resolution nerve ultrasound in carpal tun- nel syndrome. “Some patients fear electrical stimulation and may be good candidates for examina- tion using ultrasonography,” Dr. Nalini told Elsevier’s PracticeUpdate . Ultrasonography was performed using the Philips Epiq 7G, linear 5 to 18Hz transducer. Median nerve cross-sectional area was

recorded transversely at level of pisiform and scaphoid bones parallel to each other (carpal tunnel inlet). Distal-to-proximal ratio was calculated 4 cm from the distal crease in the forearm. Nerve conductions were performed as per standard procedure. Magnetic resonance neurography axial and sagittal images employed a temporo- mandibular surface coil, fat saturation, and flow suppression. A total of 30 participants were studied. Female to male ratio was 4:1. Mean age at presentation was 41.6 ± 10.5 (27 to 61) years. Clinically, 28 (93.3%) suffered from bilateral carpal tunnel syndrome (n=4 symmetrical, n=24 asymmetrical) and 2 exhibited uni- lateral involvement. The duration of illness varied from 2 months to 8 years. All participants voiced sensory complaints. A total of nine patients (30%) also suffered from motor deficits. Sensitivity of Tinel sign/Phalen’s maneuver was 40% and 63.3%, respectively. Using ultrasonogra- phy, cross-sectional area at the pisiform bone level was >0.1 cm 2 .

• Right 7.2 ± 5.3 (1.5 to 23) mV • Left: 9.9 ± 5.9 (2.3 to 22.1) mV Conduction velocities were: • Right 35.6 ± 11 (11.7 to 58) m/s • Left 43.7 ± 13 (22.2 to 68.6) m/s

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