Minimally important differences for subjective improvement in postural stability in patients with bilateral vestibulopathy

Chisato Fujimoto; Takuya Kawahara; Makoto Kinoshita; Kentaro Ichijo; Mineko Oka; Teru Kamogashira; Keiko Sugasawa; Tatsuya Yamasoba; Shinichi Iwasaki

doi:10.1016/j.neulet.2021.135706

Minimally important differences for subjective improvement in postural stability in patients with bilateral vestibulopathy

Neurosci Lett. 2021 Mar 16:747:135706. doi: 10.1016/j.neulet.2021.135706. Epub 2021 Feb 3.

Authors

Chisato Fujimoto¹, Takuya Kawahara², Makoto Kinoshita³, Kentaro Ichijo⁴, Mineko Oka⁵, Teru Kamogashira⁶, Keiko Sugasawa⁷, Tatsuya Yamasoba⁸, Shinichi Iwasaki⁹

Affiliations

¹ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: cfujimoto-tky@umin.ac.jp.
² Clinical Research Promotion Center, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: tkawahara-tky@umin.ac.jp.
³ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: kinoshitam-zao@umin.ac.jp.
⁴ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: ichijokentaro@gmail.com.
⁵ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: minekos98@gmail.com.
⁶ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: tkamogashira-tky@umin.ac.jp.
⁷ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: keisuga-tky@umin.ac.jp.
⁸ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. Electronic address: tyamasoba-tky@umin.ac.jp.
⁹ Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan; Department of Otolaryngology, Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan. Electronic address: iwashin-tky@umin.ac.jp.

PMID: 33548406
DOI: 10.1016/j.neulet.2021.135706

Abstract

Objective: To determine minimally important differences (MIDs) for subjective improvement in postural stability after a therapeutic intervention in patients with bilateral vestibulopathy (BVP).

Methods: Thirteen BVP patients received noisy galvanic vestibular stimulation (nGVS) for 30 min and their static posture with eyes closed was monitored after the stimuli. The velocity of the center of pressure (COP) movement, the area enclosed by the COP movement, and the root mean square (RMS) of the displacement of the COP were measured for 30 s. Subjective evaluation of postural stability after nGVS was graded as worsened, slightly worsened, unchanged, slightly improved and improved in comparison with postural stability measured without nGVS. Anchor-based methods were used to estimate MIDs for subjective improvement. Velocity, area and RMS for each anchor-response group were averaged (2 sessions, each with 5 measurement periods during 3 h after the stimuli). The mean changes between the slightly improved group and unchanged group were used as estimates for MID for improvement.

Results: A total of 129 anchors were analyzed. Subjective evaluations numbered 83 (64%) for unchanged and 33 (26%) for slightly improved. Anchor-based methods yielded estimates for MIDs of -0.43 cm/s in velocity improvement (p < 0.01), -0.77 cm² for area improvement (p < 0.01) and -0.23 cm for RMS improvement (p < 0.001).

Conclusion: The present study provides the estimation of MIDs for improving postural stability in BVP patients and may be useful for interpreting whether the results from clinical trials are meaningful in future studies.

Keywords: Bilateral vestibulopathy; Minimally important differences; Posture.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Aged, 80 and over
Bilateral Vestibulopathy / therapy*
Electric Stimulation / methods
Female
Humans
Male
Middle Aged
Movement / physiology*
Noise
Postural Balance / physiology*
Posture / physiology*
Vestibule, Labyrinth / physiology