title: Electrical impedance myography in the detection of radiculopathy.
abstract: Electrical impedance myography (EIM) is a new bioimpedance-based technique for neuromuscular disease assessment. Past work has focused on EIM in the evaluation of diffuse diseases (such as myopathy). In this study, the method's most basic form, linear-EIM, was used for the assessment of restricted radiculopathic disease. Ten normal subjects and 10 patients with unilateral cervical or lumbosacral radiculopathy, diagnosed by electromyography and clinical criteria, were enrolled. Linear-EIM was performed bilaterally on all individuals, and comparisons with the major outcome variable, theta(avg), were made. In normal subjects, side-to-side differences in theta(avg) averaged 0.64% and were no greater than 15.9% in magnitude. In the 10 patients with radiculopathy, theta(avg)was consistently lower in the affected extremity, with a mean side-to-side difference of 15.3%, but ranging as low as 72.3%; there was a tendency for muscles with more prominent chronic neurogenic change to show greater relative reductions in theta(avg). These findings support the potential utility of EIM in assessment of localized neuromuscular disease.
authors.affiliation: Department of Neurology, Division of Neuromuscular Diseases, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA. srutkove@bidmc.harvard.edu
authors.forename: Seward B
authors.initials: SB
authors.lastname: Rutkove
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Esper
authors.forename: Kyungmouk S
authors.initials: KS
authors.lastname: Lee
authors.forename: Ronald
authors.initials: R
authors.lastname: Aaron
authors.forename: Carl A
authors.initials: CA
authors.lastname: Shiffman
mesh_terms: D001132:Arm / Q000294:innervation / Q000503:physiopathology; D001917:Brachial Plexus / Q000503:physiopathology; D017097:Electric Impedance; D004558:Electric Stimulation / Q000379:methods*; D004576:Electromyography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007866:Leg / Q000294:innervation / Q000503:physiopathology; D008160:Lumbosacral Plexus / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation* / Q000503:physiopathology*; D009468:Neuromuscular Diseases / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011843:Radiculopathy / Q000175:diagnosis* / Q000503:physiopathology; D012016:Reference Values