Print version ISSN 0004-282X
Arq. Neuro-Psiquiatr. vol.56 n.4 São Paulo Dec. 1998
CARPAL TUNNEL SYNDROME: CLINICAL, EPIDEMIOLOGICAL AND NERVE CONDUCTION STUDIES IN 668 CASES (ABSTRACT)*. DISSERTATION. SÃO JOSÉ DO RIO PRETO, 1998.
JOÃO ARIS KOUYOUMDJIAN **
Between January 1989 and June 1996, 1059 carpal tunne syndrome hands (CTS) from 668 patients were studied. None had been previously operated and all had bilateral conduction studies; peripheral neuropathy was excluded. The patients were selected with sensory median/radial difference (MRD) > 1.0 ms that strongly supports electrodianosis of CTS (standard deviation > 6) after simultaneous stimulation on wrist and recording on thumb.
The age ranged from 17 to 83 years (mean 47.5) and 91.3% were female; the complaints were bilateral in 72% and nocturnal/awakening in 85.3%; pain, numbness and paresthesia occurred in 64.4%; pain as the only symptom was rare but proximal extension was frequent (39.4%); all fingers were symptomatic in 42.5%, followed by middle, middle-ring, thumb-index-middle and then index-middle-ring ones; there was no correlation with traumatic past history on wrist. The duration of CTS symptoms ranged from 1 to >120 months without precise correlation with the severity of conduction abnormalities on median nerve.
MRD > 1.0 ms correlates in 95% with median nerve distal motor latency >4.25 ms (80 mm distance) and with median distal sensory latency to index finger > 3.01 ms, middle finger > 3.14 ms and ring finger > 3.26 ms, all of them 140 mm distance antidromic and onset-measured.
The results have brought new values for the limit of normality in our EMG laboratory since MRD > 1.0 ms is very sensitive for CTS diagnosis.
KEY WORDS: carpal tunnel syndrome, entrapment neuropathy, electroneuromyography.
*Síndrome do túnel do carpo: aspectos clínico-epidemiológicos e de condução nervosa em 668 casos (Resumo). Dissertação de Mestrado, Faculdade de Medicina de Ribeirão Preto (Área: Biologia Médica). Orientador: Alceu Gomes Chueire.