Ocular torsions and the subjective visual vertical with central vestibulo-ocular system lesions: Independence disproved

摘要

Objectives: Torsions of the eyes and deviations of the subjective visual vertical in roll occur regularly with disorders of the central vestibulo-ocular system. Although nearly universally coexisting, torsions and deviation have been held to be more or less independent of each other. Materials and methods: Angles of torsion were determined from fundus photographs in 55 subjects representing a variety of acute, focal, brainstem or cerebellar lesions. Measured torsions were contrasted with quantitative measurements of the subjective visual vertical. Results: Torsions and deviations proved to be directly proportional, with a direction coefficient close to unity, and were strongly correlated (r = 0.86). Conclusions: Torsions and deviations are strongly dependent. This result should allow the generation of a more transparent pathophysiological model. From a practical point of view, measurements of deviation appeared more robust than those of torsion.