title: The modified gait abnormality rating scale in patients with a conversion disorder: a reliability and responsiveness study.
abstract: Individuals with conversion disorder have neurologic symptoms that are not identified by an underlying organic cause. Often the symptoms manifest as gait disturbances. The modified gait abnormality rating scale (GARS-M) may be useful for quantifying gait abnormalities in these individuals. The purpose of this study was to examine the reliability, responsiveness and concurrent validity of GARS-M scores in individuals with conversion disorder. Data from 27 individuals who completed a rehabilitation program were included in this study. Pre- and post-intervention videos were obtained and walking speed was measured. Five examiners independently evaluated gait performance according to the GARS-M criteria. Inter- and intrarater reliability of GARS-M scores were estimated with intraclass correlation coefficients (ICCs). Responsiveness was estimated with the minimum detectable change (MDC). Pre- to post-treatment changes in GARS-M scores were analyzed with a dependent t-test. The correlation between GARS-M scores and walking speed was analyzed to assess concurrent validity. GARS-M scores were quantified with good-to-excellent inter- (ICC = 0.878) and intrarater reliability (ICC = 0.989). The MDC was 2 points. Mean GARS-M scores decreased from 7 ± 5 at baseline to 1 ± 2 at discharge (t26 = 7.411, p < 0.001) and 85% of patients improved beyond the MDC. Furthermore, GARS-M scores and walking speed measurements were moderately correlated (r = -0.582, p = 0.004), indicating that the GARS-M has acceptable concurrent validity. Our findings provide evidence that the GARS-M scores are reliable, valid and responsive for quantifying gait abnormalities in patients with conversion disorder. GARS-M scores provide objective measures upon which treatment effects can be assessed.
authors.affiliation: Department of Physical Medicine & Rehabilitation, Program in Physical Therapy, Mayo School of Health Sciences, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Justin M
authors.initials: JM
authors.lastname: Vandenberg
authors.affiliation: Department of Physical Medicine & Rehabilitation, Program in Physical Therapy, Mayo School of Health Sciences, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Deanna R
authors.initials: DR
authors.lastname: George
authors.affiliation: Department of Physical Medicine & Rehabilitation, Program in Physical Therapy, Mayo School of Health Sciences, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: O'Leary
authors.affiliation: Department of Physical Medicine & Rehabilitation, Program in Physical Therapy, Mayo School of Health Sciences, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Lindsay C
authors.initials: LC
authors.lastname: Olson
authors.affiliation: Department of Physical Medicine & Rehabilitation, Program in Physical Therapy, Mayo School of Health Sciences, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Kaitlyn R
authors.initials: KR
authors.lastname: Strassburg
authors.affiliation: Department of Physical Medicine & Rehabilitation, Program in Physical Therapy, Mayo School of Health Sciences, Mayo Clinic College of Medicine, Rochester, MN, USA. Electronic address: vandenberg.justin@mayo.edu.
authors.forename: John H
authors.initials: JH
authors.lastname: Hollman
mesh_terms: D000328:Adult; D003291:Conversion Disorder / Q000150:complications*; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D009069:Movement Disorders / Q000209:etiology / Q000534:rehabilitation*; D026741:Physical Therapy Modalities / Q000295:instrumentation*; D015203:Reproducibility of Results; D014743:Videotape Recording; D016138:Walking / Q000145:classification*
keywords: Conversion disorder; Movement disorders; Reproducibility of results; Videotape recording; Walking