Long-term Evolution of Subjective Visual Vertical after Vestibular Neurectomy and Labyrinthectomy

Abstract

Subjective visual vertical (SVV) tilt, observed after vestibular neurectomy and labyrinthectomy, is considered to be due to the deafferentation of the otolithic organs. The aim of this study was to determine the long-term evolution of the SVV up to 4 years after surgery. Between 1993 and 1998 the SVV was measured in 35 patients (18 men, 17 women) aged from 21 to 71 years (mean 36 years). Vestibular neurectomy was performed in 30 patients and labyrinthectomy in 6. SVV was measured with a binocular test (vertical frame) and a monocular test (Maddox rod). Immediately after operation, the SVV showed a 10-30 degrees tilt toward the operated ear with the vertical frame (normal 0 +/- 2 degrees) and a 5-22 degrees tilt with the Maddox rod (normal 0 +/- 4 degrees). After labyrinthectomy, SVV returned to normal values after 1 year in all patients. SVV also returned to normal within 1 year after vestibular neurectomy in 20 patients; in the other 10 patients SVV was still slightly tilted 1-4 years after neurectomy: > 2 degrees with the vertical frame and > 4 degrees with the Maddox rod, particularly on the eye ipsilateral to the operated ear. Some of these 10 patients also had persisting disequilibrium.

Mental transformation abilities in patients with unilateral and bilateral vestibular loss

“…This confirms findings from earlier studies and shows that the SVV can still be an indicator of the lesioned side in otherwise well-compensated patients (Bohmer and Mast 1999a, b;Vibert and Hausler 2000;Lopez et al 2006;Lopez et al 2007). BVPs and CPs adjusted the SVV with little deviation from the upright.…”

Recovery after Vestibular Lesions: From Animal Models to Patients

“…Third, it suggests that this deficit, while well compensated 1 week after the lesion using an adaptive strategy, is in fact a long-lasting problem, which is obviously of importance for the rehabilitation of these patients [112,126] . Two previous findings in unilateral vestibular loss patients are in good agreement with these conclusions: the deviation in the subjective vertical of these patients could last up to 4 years [127,128] . Also, their trunk stabilization in the roll plane remained impaired up to 3 months after the lesion, during a natural task of knee bends [87] and complex gait tasks [129] .…”

Percepción de la vertical visual subjetiva. Medición y utilidad diagnóstica

“…Estos autores, por tanto, consideran que la evaluación clínica de la VVS debería ser realizada en todos los pacientes con un desequilibrio tonal vestibular. A nivel vestibular periférico, después de una desaferentización total vestibular unilateral aguda de un laberinto previamente normal, por ejemplo, tras una neurectomía, la VVS se inclina hacia el lado lesionado en al menos 25º o más [12,13]. La instilación intratimpánica de gentamicina para el tratamiento de la enfermedad de Ménière tiene un efecto similar en la percepción de la vertical, con una desviación significativa hacia el lado tratado en relación a la medición pretratamiento [14].…”