Affiliations: [a] Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA | [b] Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
Correspondence:
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Corresponding author: Michael C. Schubert, PT, PhD, Department of Otolaryngology Head and Neck Surgery, Johns Hopkins School of Medicine, 601 N. Caroline St, JHOC Room 6245, Baltimore, MD 21287-0910, USA. Tel.: +1 410 955 3403; Fax: +1 410 955 6526; E-mail: mschube1@jhmi.edu
Abstract: The recruitment of extra-vestibular mechanisms to assist a deficient angular vestibulo-ocular reflex (aVOR) during ipsilesional head rotations is well established and includes saccades of reduced latency that occur in the direction of the lesioned aVOR, termed compensatory saccades (CS). Less well known is the functional relevance of these unique saccades. Here we report a 42 y.o. male diagnosed with right unilateral vestibular hypofunction due to vestibular neuronitis who underwent a vestibular rehabilitation program including gaze stabilization exercises. After three weeks, he had a significant improvement in his ability to see clearly during head rotation. Our data show a reduction in the recruitment and magnitude of CS as well as improved peripheral aVOR gain (eye velocity/head velocity) and retinal eye velocity. Our data suggest an inverse, dynamic relationship between the recruitment of CS and the gain of the aVOR.
