OBJECTIVE: The median nerve is responsible for the motor innervation of most of the muscles usually involved in upper limb spasticity. Selective neurectomy is one of the treatments utilized to reduce spasticity. The purpose of this study was to describe the variations of the motor branches of the median nerve in the forearm and draw recommendations for an appropriate planning of selective neurectomy.
METHODS: The median nerve was dissected in the forearm of 20 fresh cadaver upper limbs. Measurements included number, origin, division, and entry point of each motor branch into the muscles.
RESULTS: One branch for the pronator teres was the most common pattern. In 9/20 cases, it arose as a common trunk with other branches. A single trunk innervated the flexor carpi radialis with a common origin with other branches in 17/20 cases. Two, three or four branches innervated the flexor digitorum superficialis, the first one frequently through a common trunk with other branches. They were very difficult to identify unless insertions of pronator teres and flexor digitorum superficialis were detached. The flexor digitorum profundus received one to five branches and flexor pollicis longus one to two branches from the anterior interosseous nerve.
CONCLUSIONS: There is no regular pattern of the motor branches of the median nerve in the forearm. Our findings differ in many points from the classical literature. Because of the frequency of common trunks for different muscles, we recommend the use of peroperative electrical stimulation. Selective neurotomy of flexor digitorum superficialis is technically difficult, because the entry point of some of their terminal branches occurs just below the arch and deep to the muscle belly.

BACKGROUND: The purpose of this study was to develop an evidence-based guideline for the use of neuromuscular ultrasound in the diagnosis of carpal tunnel syndrome (CTS).
METHODS: Two questions were asked: (1) What is the accuracy of median nerve cross-sectional area enlargement as measured with ultrasound for the diagnosis of CTS? (2) What added value, if any, does neuromuscular ultrasound provide over electrodiagnostic studies alone for the diagnosis of CTS? A systematic review was performed, and studies were classified according to American Academy of Neurology criteria for rating articles of diagnostic accuracy (question 1) and for screening articles (question 2).
RESULTS: Neuromuscular ultrasound measurement of median nerve cross-sectional area at the wrist is accurate and may be offered as a diagnostic test for CTS (Level A). Neuromuscular ultrasound probably adds value to electrodiagnostic studies when diagnosing CTS and should be considered in screening for structural abnormalities at the wrist in those with CTS (Level B).

The purpose of this research was to identify the number of sessions required for a new investigator to become proficient at evoking an H-reflex in the flexor carpi radialis (FCR), in comparison to an experienced investigator. 31 students from Brock University in the greater Niagara region (16 women M age = 32.2, SD = 8.9 yr.; 15 men M age = 27.8, SD = 7.8 yr.) with no known neurological disorders volunteered and completed two test sessions performed by either an experienced or a novice investigator. In randomized order, both investigators stimulated each subject\'s median nerve 10 times, once every 15 sec. Each session included the measurement of the subject\'s flexor carpi radialis maximal M-wave amplitude and H-reflex amplitude and latency with surface electromyographic electrodes. The intraclass correlation coefficients (ICC) indicated an adequate correlation between investigators for both M-wave maximal amplitude and H-reflex at 5% of the M-wave maximal amplitude (.84 and .70, respectively). However, there was a low correlation (.38) between the latency values obtained by the two investigators. The peak-to-peak amplitudes of the H-reflex and M-wave do not appear to be influenced by experience of the tester. The latency of the response, however, appears to have an associated learning curve, improving in consistency with increasing practice of tester.

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OBJECTIVE: To describe how clinical practice in those who underwent carpal tunnel release (CTR) matched the American Association of Electrodiagnostic Medicine (AAEM) 1993 practice parameters for electrodiagnostic evaluation of carpal tunnel syndrome (CTS).
METHODS: Cohort study using 1998-1999 Medicare billing data.
METHODS: Washington State.
METHODS: State Medicare beneficiaries who underwent CTR in 1999 (N=1567) Interventions Not applicable.
METHODS: Compliance with the AAEM practice parameters.
RESULTS: Of the 1567 [corrected] receiving surgery, 324 [corrected] (20.7%) did not have any electrodiagnostic testing before surgery. One hundred seventy-one (10.9%) had testing performed that did not lead to the diagnosis of CTS. One thousand seventy-two (68.4%) patients were diagnosed with CTS through electrodiagnostic testing; 155 (9.9%) had less than 2 sensory nerves studied, 114 (7.3%) had less than 2 motor nerves studied, and 65 (4.2%) of the studies met neither the standard (sensory nerve testing) nor guideline (motor nerve testing). In a multivariate analysis, neurologists were more likely than physiatrists not to meet the AAEM standards (adjusted relative risk [adj RR]=1.61; 95% confidence interval [CI], 1.13-2.31) and patients living in rural areas were more likely to have no or inadequate testing (adj RR=1.6; 95% CI, 1.3-1.9).
CONCLUSIONS: Over one third of Medicare patients undergoing CTR in Washington State in 1999 may have had an inappropriate electrodiagnostic workup before the surgery. Policymakers should consider mandating an appropriate electrodiagnostic test before approving CTR.

The testing of nerve conduction using electromyography (EMG) is a frequently used diagnostic method for the identification of various neuropathies. The present article illustrates a variety of conditions on the basis of clinical data, and suggests how one can obtain the best results by observing a few simple rules.