Abducens Nerve Palsy (Sixth Cranial Nerve Palsy) Workup

Updated: Mar 02, 2021
  • Author: Michael P Ehrenhaus, MD; Chief Editor: Edsel B Ing, MD, PhD, MBA, MEd, MPH, MA, FRCSC  more...
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Laboratory Studies

See the list below:

  • Complete blood cell (CBC) count
  • Diabetes testing (glucose, glycosylated hemoglobin [HbA1C], glucose tolerance test)
  • Erythrocyte sedimentation rate, C-reactive protein, and platelets in patients older than 50 years
  • Acetylcholine receptor antibodies in the presence of variable strabismus or ptosis

The following are not mainstream tests for abducens palsy but can be considered:

  • Rapid plasma reagin test
  • Fluorescent treponemal antibody-absorption test
  • Lyme titer
  • Antinuclear antibody test

Imaging Studies

MRI is indicated for the following:

  • Patients younger than 55 years with no vasculopathic history
  • Associated pain or other neurologic abnormality [11]
  • History of cancer
  • Bilateral sixth nerve palsy
  • Papilledema
  • In the event no marked improvement is seen or other nerves become involved

An LP should be considered if MRI results are negative.

If a presumed microvascular ischemic sixth nerve palsy does not improve within 3-4 months or if other cranial nerves become involved, a full medical, neurologic, and imaging workup should be performed.


Other Tests

Check history for diabetes mellitus, cancer, thyroid disease, and hypertension.

Ask about history of recent trauma, ear infections (children), and fluctuation of symptoms.

An otoscopic examination may be performed in children to rule out a complicated otitis media (consider an LP).

Rule out other cranial nerve involvement.



A temporal artery biopsy may be indicated in patients aged 50 years or older with findings and laboratory studies suggestive of giant cell arteritis.