What are the symptoms of third cranial nerve palsy (oculomotor cranial nerve palsy) associated with lesions?

Updated: Oct 08, 2018
  • Author: James Goodwin, MD; Chief Editor: Andrew G Lee, MD  more...
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The following symptoms are encountered with lesions producing third cranial nerve dysfunction:

  • The most common lesions to affect the third cranial nerve involve the peripheral nerve or fascicular portion of the nerve at some level. The symptoms reflect reduced function in the muscles innervated by the nerve, usually in combination; isolated involvement of one or another muscle from nuclear or fascicular third cranial nerve lesions is very rare. The prime symptom is mixed horizontal and vertical binocular diplopia.
  • Ptosis may be partial or complete. Nuclear lesions that spare the central caudate subnucleus to the levator palpebrae superioris may produce third nerve palsies without ptosis. If the ptosis is sufficient to cover the pupil, the patient may complain that he or she cannot see from the eye on the involved side or may not have diplopia because the ptosis is acting as an “occluder.”
  • Ipsilateral pupil mydriasis, anisocoria, and lack of light/near reaction produces little in the way of symptoms, although there may be some glare sensation and photo aversion in bright light.

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