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Standardization of anal sphincter electromyography: Utility of motor unit potential parameters
Author(s) -
Podnar Simon,
Vodušek David B.
Publication year - 2001
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.1093
Subject(s) - motor unit , electromyography , conus medullaris , external anal sphincter , cauda equina , medicine , anal sphincter , nuclear medicine , anatomy , physical medicine and rehabilitation , surgery , magnetic resonance imaging , radiology , spinal cord , psychiatry , rectum , anal canal
Advanced electromyography systems offer quantitative analysis of a number of motor unit potential (MUP) parameters. However, only limited data are available on the diagnostic usefulness of these parameters. In the present study, we compared the sensitivities of MUP parameters in revealing “neuropathic” changes in the external anal sphincter (EAS) muscles in 56 patients examined 5–240 months after damage to the cauda equina or conus medullaris. Using multi‐MUP analysis, 20 MUPs were obtained from patients' EAS muscles. Their MUP parameters were compared with normative data from 64 controls. The diagnostic sensitivities of mean values/“outliers” of MUP parameters for detecting neuropathic EAS muscles were calculated (area 25%/30%; number of turns 18%/29%; size index 13%/24%; thickness 18%/18%; amplitude 17%/17%; spike duration 20%/9%; duration 15%/12%; number of phases 15%/11%; and their combination 51%/52%). Altogether, the cumulative sensitivity of multi‐MUP analysis using both mean values and “outliers” was 62%. The combination of MUP parameters improves the diagnostic yield of MUP analysis, but the influence on specificity remains unknown. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 946–951, 2001