UNILATERAL VESTIBULAR DEAFFERENTATION - A MODEL OF ADAPTATION

After acute loss of peripheral vestibular function, a centrally adapti ve process takes place. Clinical measurements of vestibular adaptation are useful, both diagnostically and as a means of following patients after acute vestibular deficits. Ocular torsion is one measurement tha t can be used to follow these acutely disabled patients. The measureme nt is made from fundus photographs and is technically easy to perform and interpret. We present a pilot study from our Vestibular Disorders Clinic using fundus photography to measure the optic nerve head-foveal angle in six patients undergoing unilateral vestibular neurectomy, wi th subsequent analysis resulting in a speculative mathematical model o f vestibular compensation in the roll plane. While the identification or selection of patients with significant ocular torsions from the ves tibular population remains ill-defined, fundus photography remains an easy and useful method of following compensation in postoperative pati ents.