Exam

Skew Deviation

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Skew Deviation, Vertical Ocular Misalignment, Vertical Heterotropia, Vertical Strabismus, Vertical Squint, Hypertropia, Hypotropia, Test of Skew

  • Definitions
  1. Skew Deviation (Vertical Ocular Misalignment, Vertical Strabismus, Vertical Heterotropia or Vertical Squint)
    1. Eye gaze deviation due to abnormal vestibular system inputs
      1. Typically from a posterior circulation Cerebrovascular Accident (Cerebellar CVA or Brainstem CVA)
    2. One eye may be directed forward normally, while the the other is directed either up (Hypertropia) or down (Hypotropia)
  • Exam
  1. Perform as with Alternate Eye Cover Test (used to evaluate for horizontal Strabismus in children)
  2. Alternately cover one eye and then the other
  3. Observe for quick vertical gaze corrections (abnormal)
    1. Uncovered eye shifts to center from its abnormal, vertically displaced position
  • Interpretation
  1. Abnormal skew test with quick vertical gaze corrections suggests a central cause (e.g. Brainstem CVA) of Acute Vestibular Syndrome
  • Associated Conditions
  1. Head Tilt
    1. Often accompanies Skew Deviation
  • References
  1. Kattah (2009) Stroke 40: 3504-10 [PubMed]