Median and ulnar palm-wrist studies

• Published in: Clinical neurophysiology Vol. 110; no. 8; pp. 1462 - 1465
• Main Authors: SANDER, H. W, QUINTO, C, SAADEH, P. B, CHOKROVERTY, S
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Science 01.08.1999
• Subjects: Adult; Aged; Biological and medical sciences; Carpal Tunnel Syndrome - diagnosis; Carpal Tunnel Syndrome - physiopathology; Electrodiagnosis. Electric activity recording; Electromyography; Humans; Investigative techniques, diagnostic techniques (general aspects); Median Nerve - physiology; Medical sciences; Middle Aged; Nervous system; Neural Conduction - physiology; Ulnar Nerve - physiology; Wrist - physiology; Human; Carpal tunnel syndrome; Nervous system diseases; Compression; Cubital nerve; Diseases of the osteoarticular system; Wrist; Nerve conduction; Electrodiagnosis; Normative value; Median nerve; Palm; Response latency; Electromyography; Peripheral nerve disease
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/S1388-2457(99)00069-3

Routine carpal tunnel electrodiagnosis frequently includes median (MPW) and ulnar (UPW) palm-wrist mixed nerve conduction latency determinations over 8 cm. Despite widespread use, normative palmar latency difference (PLD) and UPW values, and the relative utility of onset latency (OL) or peak latency (PL) measurements are controversial. The current study was conducted to determine normative values for these parameters. MPW and UPW studies were performed unilaterally in 33 normal controls. The PLD-OL and PLD-PL were calculated. The mean, range, standard deviation, and upper limits of normal were determined. 74 hands (50 patients) with both clinical and electrophysiologic median neuropathy were also studied. The abnormal MPW and UPW cut-offs were both 1.8 ms (OL), and 2.3 ms (PL). The abnormal PLD cut-offs were 0.5 ms (OL and PL). Using either OL or PL, PLD parameters were similar within controls, and also within CTS patients. Using either OL or PL, UPW parameters were similar between controls and CTS patients. An abnormal PLD cut-off of 0.5 is recommended. This is slightly higher than some prior recommendations, however it should minimize the likelihood of false positive studies. Onset and peak latency measurements are likely to have similar clinical utility.