II. Definitions
- Skew Deviation (Vertical Ocular Misalignment, Vertical Strabismus, Vertical Heterotropia or Vertical Squint)
- Eye gaze deviation due to abnormal vestibular system inputs
- Typically from a posterior circulation Cerebrovascular Accident (Cerebellar CVA or Brainstem CVA)
- One eye may be directed forward normally, while the the other is directed either up (Hypertropia) or down (Hypotropia)
- Eye gaze deviation due to abnormal vestibular system inputs
III. Exam
- Perform as with Alternate Eye Cover Test (used to evaluate for horizontal Strabismus in children)
- Alternately cover one eye and then the other
- Observe for quick vertical gaze corrections (abnormal)
- Uncovered eye shifts to center from its abnormal, vertically displaced position
IV. Interpretation
- Abnormal skew test with quick vertical gaze corrections suggests a central cause (e.g. Brainstem CVA) of Acute Vestibular Syndrome
V. Associated Conditions
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Head Tilt
- Often accompanies Skew Deviation