Does the comparison of median-to-ulnar nerve sensory conduction add an additional value in electrodiagnosis of carpal tunnel syndrome?

Temperature is an important and common variable that modifies nerve conduction study parameters in practice. Here we compare the effect of cooling on the mixed palmar median to ulnar negative peak-latency difference (PMU) in electrodiagnosis of carpal tunnel syndrome (CTS). Controls were 22 subjects (19 women, mean age 42.1 years, 44 hands). Patients were diagnosed with mild symptomatic CTS (25 women, mean age 46.6 years, 34 hands). PMU was obtained at the usual temperature, >32°C, and after wrist/hand cooling to <27°C in ice water. After cooling, there was a significantly greater increase in PMU and mixed ulnar palmar latency in patients versus controls. We concluded that cooling significantly modifies the PMU. We propose that the latencies of compressed nerve overreact to cooling and that this response could be a useful tool for incipient CTS electrodiagnosis. There was a significant latency overreaction of the ulnar nerve to cooling in CTS patients. We hypothesize that subclinical ulnar nerve compression is associated with CTS.

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High incidence of absent nerve conduction in older patients with bilateral carpal tunnel syndrome

Annals of The Royal College of Surgeons of England ◽

10.1308/003588410x12628812460092 ◽

2010 ◽

Vol 92 (5) ◽

pp. 403-405 ◽

Cited By ~ 5

Author(s):

BO Povlsen

Keyword(s):

Carpal Tunnel Syndrome ◽

Carpal Tunnel ◽

Nerve Conduction ◽

Older Patients ◽

Age Group ◽

Sensory Conduction ◽

Satisfactory Outcome ◽

High Incidence ◽

Tunnel Syndrome ◽

Bilateral Carpal Tunnel Syndrome

INTRODUCTION Carpal tunnel syndrome has been reported by some to have a less satisfactory outcome in older patients following surgery. However, this impression is not supported by other investigators but no objective explanation has been suggested for these differences. In our department, such patients are routinely treated with night wrist splints and, if this is unsatisfactory, they are investigated with nerve conduction studies prior to surgery. PATIENTS AND METHODS This paper reports the neurophysiological outcome in a young (< 40 years of age) and an older (> 60 years of age) group of patients with clinical bilateral carpal tunnel syndrome who did not benefit from splints. RESULTS The results showed that both the motor and sensory conduction speeds are significantly lower in the older age group. More importantly in the older group, half had one or more hands where the sensory conduction was absent. In four out of these 10 patients this finding was bilateral and three patients had unilateral absent motor conduction. In the younger group, no patient had absent conduction. CONCLUSIONS Poor surgical outcome in some older patients may be because of irreversibly damaged nerves prior to surgery and pre-operative neurophysiology is, therefore, recommended both for clinical and medicolegal reasons.

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