Novel characterization of subjective visual vertical in patients with unilateral spatial neglect. (February 2021)

• Record Type: Journal Article
• Authors: Mori, Kimihiko; Nakamura, Kae; Hashimoto, Shingo; Wakida, Masanori; Hase, Kimitaka
• Is Part Of: Neuroscience research. Volume 163(2021)
• Page Start: 18
• Page End: 25
• Publication Date: 2021-02
• Subjects: VV visual vertical -- USN unilateral spatial neglect -- SLF superior longitudinal fasciculus -- VVm mean visual vertical -- VVsd standard deviation of visual vertical -- ANOVA analysis of variance; Visual vertical -- Unilateral spatial neglect -- Subacute stroke -- Visuospatial cognition -- Classification -- Multisensory integration; Neurosciences -- Research -- Periodicals; Neurosciences -- Research -- Japan -- Periodicals; Neurology -- Periodicals; Neurosciences -- Periodicals; Neurosciences -- Recherche -- Périodiques; Neurosciences -- Recherche -- Japon -- Périodiques; Neurosciences -- Research; Japan; Periodicals; 612.8
• DOI: 10.1016/j.neures.2020.02.005
• Languages: English
• ISSNs: 0168-0102

Abstract

Highlights: Characterization of visual vertical (VV) in subacute stroke patients was performed. Subjects judged vertical direction of a line rotating from right- or left-tilt. Patients with unilateral spatial neglect showed VV deviating from the normal range. In all groups, VV deviated towards the initial direction of the tilt of the line. Combined VV orientation and variability characterize verticality perception better. Abstract: Visual vertical (VV), visually perceived direction of gravity, is widely measured to assess the vestibular function and visuospatial cognition. VV has been assessed by comparing orientation and variability of measured values separately between subject groups. However, changes in orientation and variability often differ in patients with unilateral spatial neglect (USN). Here, we developed a novel classification of VV that combines orientation and variability and characterized the effects of USN on VV. Forty-three subacute stroke patients with or without USN (USN+, n = 17; USN-, n = 26) and 33 age-matched controls were included in the study. In darkness, a luminous line, initially tilted at 30° either to the left or right, gradually rotated towards the vertical. The VV was defined as the deviation of the subjectively-perceived vertical from the true vertical. The new classification demonstrated that, while the majority of USN + patients (14/17) exhibited large variability, nine showed normal orientation and five showed greater contra-lesional deviation of orientation, suggesting different underlying mechanisms for orientation and variability. Further analyses revealed VV deviation to the initial tilt in all groups. However, the deviation in USN + was larger and more variable, indicating attentional disorders. Such characterization would contribute to individually specified clinical rehabilitation.