Vestibular cortex lesions affect the perception of verticality

TLDR

The posterior insula, homologous to the parieto‑insular vestibular cortex, is believed to integrate multisensory vestibular signals, as animal studies show multiple multisensory areas in the parietal lobe. The study aimed to identify the human cortical regions responsible for roll‑plane vestibular function. Seventy‑one patients with unilateral supratentorial strokes were evaluated for roll‑plane vestibular function (subjective visual vertical, skew deviation, ocular torsion) and their lesion locations were mapped onto a brain atlas. Posterior and anterior cerebral artery infarcts did not impair roll‑plane vestibular function, whereas middle cerebral artery territory strokes produced significant contraversive subjective visual vertical tilts in 23 of 52 patients.

Abstract

Abstract Seventy‐one patients with unilateral supratentorial infarctions were evaluated with respect to static vestibular function in the roll plane, including determinations of the subjective visual vertical, skew deviation, and ocular torsion. Since animal studies have revealed at least four different areas of the parietal and temporal cortex involved in vestibular function, we tried to identify cortical areas in humans responsible for vestibular function in the roll plane. Infarcted areas, as demonstrated in magnetic resonance and computed tomography scans, were projected onto the appropriate sections of an atlas of the human brain. Infarctions in the territories of the posterior and anterior cerebral arteries did not affect static vestibular function in roll. Twenty‐three of 52 patients with infarctions in the middle cerebral artery territory showed significant ( p < 0.0005), mostly contraversive, pathological subjective visual vertical tilts. The overlapping area of these infarctions centered on the posterior insula, probably homologous to the parieto‐insular vestibular cortex in the monkey. Although electrophysiological and cytoarchitectonic data in animals demonstrate several multisensory areas rather than a single primary vestibular cortex, the parieto‐insular vestibular cortex seems to represent the integration center of the multisensory vestibular cortex areas within the parietal lobe.