title: Anal sphincter EMG does not distinguish between multiple system atrophy and Parkinson's disease.
abstract: Clinical distinction of multiple system atrophy (MSA) from Parkinson's disease (PD) is often difficult. Several recent reports indicate that objective classification may be accomplished using electromyographic (EMG) testing of the anal or urethral sphincters, but some authors have found that these tests are not reliable for this purpose. We studied 13 patients with PD and 10 with probable MSA, as diagnosed by consensus of four movement disorders specialists, according to accepted clinical criteria. Anal sphincter EMG was performed blind to the clinical diagnosis. We found no significant differences in the mean duration of motor unit potentials (MUPs), mean MUP amplitude, or prevalence of polyphasic potentials, satellite potentials, very long duration MUPs, or spontaneous activity between the two groups. Thus, anal sphincter EMG does not differentiate between PD and MSA.
authors.affiliation: Department of Neurology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv, Israel.
authors.forename: N
authors.initials: N
authors.lastname: Giladi
authors.forename: E S
authors.initials: ES
authors.lastname: Simon
authors.forename: A D
authors.initials: AD
authors.lastname: Korczyn
authors.forename: G B
authors.initials: GB
authors.lastname: Groozman
authors.forename: Y
authors.initials: Y
authors.lastname: Orlov
authors.forename: H
authors.initials: H
authors.lastname: Shabtai
authors.forename: V E
authors.initials: VE
authors.lastname: Drory
mesh_terms: D000368:Aged; D001003:Anal Canal / Q000503:physiopathology*; D003937:Diagnosis, Differential; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis* / Q000503:physiopathology*; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology*