What is skew deviation and what does it suggest?

• A. Vertical misalignment of the eyes due to brainstem/cerebellar lesion; suggests central vestibular disorder
• B. Horizontal misalignment of the eyes indicating peripheral vestibulopathy
• C. Torsional deviation due to inner ear pathology
• D. Normal eye alignment with vertigo

Answer: (A)

Skew deviation is a vertical misalignment of the eyes caused by disruption of brainstem or cerebellar control of vertical gaze. When one eye sits higher than the other on a cover test or alternate cover test, it signals a central vestibular problem rather than a peripheral inner-ear issue. This central sign points toward involvement of otolith-ocular pathways in the brainstem or cerebellum and carries clinical importance because it raises concern for central processes such as brainstem or cerebellar stroke and warrants urgent evaluation. The other descriptions don’t fit because horizontal misalignment, torsional deviation, or normal eye alignment with vertigo do not describe the specific vertical misalignment characteristic of skew deviation.