Both central (eg, brain stem, cerebellum) and peripheral (eg, vestibular, fourth cranial nerve palsy) etiologies can cause a vertical misalignment between the eyes with a resultant vertical diplopia. A vertical binocular misalignment may be due to a skew deviation, which is a nonparalytic vertical ocular misalignment due to roll plane imbalance in the graviceptive pathways. A skew deviation may be 1 component of the ocular tilt reaction. The purposes of this article are (1) to understand the pathophysiology of a skew deviation/ocular tilt reaction and (2) to be familiar with the examination techniques used to diagnose a skew and to differentiate it from mimics such as a fourth cranial nerve palsy.
The presence of a skew deviation usually indicates a brain stem or cerebellar localization. Vertical ocular misalignment is easily missed when observing the resting eye position alone.
Physical therapists treating patients with vestibular pathology from central or peripheral causes should screen for vertical binocular disorders.
Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology-Head and Neck Surgery, and Emergency Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland (D.R.G.); and Laboratory of Vestibular Neuroadaptation, Departments of Otolaryngology—Head and Neck Surgery and Physical Medicine and Rehabilitation, Johns Hopkins University, School of Medicine, Baltimore, Maryland (M.C.S.).
Correspondence: Michael C. Schubert, PT, PhD, Laboratory of Vestibular Neuroadaptation, Department of Otolaryngology—Head and Neck Surgery, Johns Hopkins University, School of Medicine, 601 North Caroline St, Rm 6245, Baltimore, MD 21287 (email@example.com).
This study was submitted for the special issue dedicated to the International Conference on Vestibular Rehabilitation.
The authors declare no conflict of interest.
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