title: Cooling modifies mixed median and ulnar palmar studies in carpal tunnel syndrome.
abstract: 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 degrees C, and after wrist/hand cooling to <27 degrees 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.
authors.affiliation: Neuromuscular Investigation Laboratory, Department of Neurological Sciences, Faculdade de Medicina de São José do Rio Preto, Rua Luiz Antônio da Silveira 1661, 15025-020 São José do Rio Preto, SP, Brazil.
authors.forename: Rogério Gayer Machado de
authors.initials: RG
authors.lastname: Araújo
authors.forename: João Aris
authors.initials: JA
authors.lastname: Kouyoumdjian
mesh_terms: D000328:Adult; D001831:Body Temperature / Q000502:physiology; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D016022:Case-Control Studies; D003080:Cold Temperature; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology*; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D011446:Prospective Studies; D011930:Reaction Time; D012720:Severity of Illness Index; D014459:Ulnar Nerve / Q000503:physiopathology*