title: Modified head shake sensory organization test: Sensitivity and specificity.
abstract: The Sensory Organization Test (SOT) of Computerized Dynamic Posturography (EquiTest™ equipment) is a valuable tool for investigating how an individual uses balance system sensory input (vestibular, vision, proprioception/somatosensory) to maintain quiet stance; however, it is limited as a screening tool for identifying peripheral vestibular system dysfunction. Previous research has shown that adding horizontal head-shake to portions of the standard SOT battery improved the identification of peripheral vestibular system asymmetry; however, flaws in the methods were noted. The objective of this work was to evaluate the sensitivity and specificity of the modified head-shake SOT (HS-SOT) protocol for identification of peripheral vestibular system lesion. Fifteen patients with chief complaint of instability, vertigo, and/or lightheadedness, with and without a caloric unilateral weakness (UW) and fifteen age-matched healthy controls were included in the final analysis. Ten of the 15 patients demonstrated a caloric UW≥25%. Participants completed standard conditions 2 and 5 of SOT with head still and during four horizontal head-shaking tasks (i.e., HS-SOT2-60°/s, HS-SOT2-120°/s, HS-SOT5-15°/s, and HS-SOT5-60°/s). Average equilibrium scores decreased as condition difficulty increased (SOT2, HS-SOT2-60°/s, HS-SOT2-120°/s, SOT 5, HS-SOT5-15°/s, and HS-SOT5-60°/s) for each group; as expected, a lower decline was noted for controls (slope=-6.59) compared to patients (slope=-11.69). The HS-SOT5-15°/s condition was superior for identifying peripheral vestibular asymmetry (AUC=0.90 sensitivity=70%, specificity=100%), with the strongest correlation to caloric UW% (rs=-0.743, p=0.000006). HS-SOT5-15°/s appears to be a promising screening measure for peripheral vestibular asymmetry.
authors.affiliation: Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE, USA. Electronic address: julie.honaker@unl.edu.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Honaker
authors.affiliation: Department of Audiology, Boys Town National Research Hospital, Omaha, NE, USA.
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Janky
authors.affiliation: Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: Jessie N
authors.initials: JN
authors.lastname: Patterson
authors.affiliation: Vestibular Laboratory, Division of Audiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Neil T
authors.initials: NT
authors.lastname: Shepard
mesh_terms: D000328:Adult; D000368:Aged; D004244:Dizziness / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011434:Proprioception; D012680:Sensitivity and Specificity; D014717:Vertigo / Q000150:complications / Q000503:physiopathology*; D014722:Vestibule, Labyrinth / Q000503:physiopathology
keywords: Caloric weakness; Calorics; Head-shake; Head-shake posturography; Peripheral vestibular; Peripheral vestibular asymmetry; Posturography; Sensory organization test; Unilateral weakness