Changes of visual vertical perception: A long-term sign of unilateral and bilateral vestibular loss

• Published in: Neuropsychologia Vol. 45; no. 9; pp. 2025 - 2037
• Main Authors: Lopez, Christophe, Lacour, Michel, Ahmadi, Abdessadek El, Magnan, Jacques, Borel, Liliane
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2007; Elsevier Science; Elsevier
• Subjects: Adult; Adult and adolescent clinical studies; Analysis of Variance; Biological and medical sciences; Cues; Ear, auditive nerve, cochleovestibular tract, facial nerve: diseases, semeiology; Female; Follow-Up Studies; Functional Laterality - physiology; Humans; Life Sciences; Male; Medical sciences; Meniere Disease - physiopathology; Meniere Disease - surgery; Menière's disease patients; Middle Aged; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Neurons and Cognition; Non tumoral diseases; Nonlinear Dynamics; Organic mental disorders. Neuropsychology; Otorhinolaryngology. Stomatology; Photic Stimulation - methods; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Roll optokinetic stimulation; Space Perception - physiology; Spatial cognition; Spatial frames of reference; Time Factors; Unilateral vestibular neurotomy; Vestibular compensation; Visual Fields - physiology; Roll optokinetic stimulation; Spatial frames of reference; Unilateral vestibular neurotomy; Menière's disease patients; Spatial cognition; Vestibular compensation; Human; Nervous system diseases; Internal ear disease; Space perception; Long term; Verticality; Vision; ENT disease; Perception; Vestibular syndrome; Meniere disease; Frame of reference
• ISSN: 0028-3932; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2007.02.004

This study investigates how unilateral and bilateral vestibular deafferentation modifies visual vertical perception in the presence of dynamic and static visual cues. We tested 40 Menière's patients before and after (from 1 week to 1 year) a curative unilateral vestibular neurotomy (UVN), and 4 patients with bilateral vestibular loss. Patients’ performances were compared with those of 24 healthy subjects. The perception of the dynamic visual vertical (DVV) was investigated during optokinetic stimulations around the line of sight at various angular velocities. The static visual vertical (SVV) was recorded with a stationary visual pattern. In the acute stage after UVN, Menière's patients exhibited drastic impairment of DVV, which was tilted towards the lesioned side, whatever the direction of the optokinetic stimulation. In addition, the SVV was systematically tilted towards the lesioned side. The optokinetic-induced tilt of the vertical was asymmetrically organized around the new SVV with a significant decrease for contralesional stimulations and no change for ipsilesional stimulations, whatever the postoperative time. The SVV regained normal values 1 year postoperatively. For the patients with bilateral vestibular loss, the optokinetic-induced tilt of the visual vertical was drastically increased and symmetrically organized around an unmodified SVV aligned with the gravitational vertical. This study constitutes the first description of the recovery time-course of DVV perception after unilateral vestibular loss. Data reveal a long-term impairment of the DVV perception after unilateral vestibular loss, suggesting an asymmetrical processing of visual information and a permanent increased weight of dynamic visual cues after bilateral vestibular loss.