What are the symptoms of oculomotor nerve palsy due to lesions in the fascicular cavernous sinus portion of the third cranial nerve?

Updated: Oct 08, 2018
  • Author: James Goodwin, MD; Chief Editor: Andrew G Lee, MD  more...
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The third cranial nerve is more susceptible to compression against the interclinoid ligaments above and the petroclinoid ligament below than are the other cranial nerves in the cavernous sinus. For this reason, isolated third cranial nerve palsy may result from lateral extension of pituitary adenoma or other primary intrasellar mass.

More diffuse lesions within the cavernous sinus, often inflammatory in nature, typically give rise to simultaneous involvement of the third, fourth, sixth, and first 2 divisions of the fifth cranial nerves in various combinations, which serve to define a cavernous sinus syndrome. The sixth cranial nerve is the most commonly affected in these cases, as it resides within, and not around, the cavernous sinus. Nonspecific, idiopathic, and presumed granulomatous inflammation within the cavernous sinus is referred to as Tolosa-Hunt syndrome, which produces an acute, steroid-responsive, painful ophthalmoplegia.

Involvement of the fourth cranial nerve in the setting of a third cranial nerve palsy should be assessed by evaluating for intorsion in downgaze. The absence of intorsion suggests concomitant fourth (on top of third) cranial nerve palsy and may localize to the ipsilateral cavernous sinus.

Often, the involvement of the first 2 divisions of the fifth cranial nerve (trigeminal) presents with severe pain and numbness in the face, including the forehead back to the interaural line and the cheek down to the angle of the mouth. The pain may be constant and burning with unpleasant paresthesia, or it may include a lancinating component that can be confused with trigeminal neuralgia.

Carotid artery dural branch to cavernous sinus fistulas typically present with third cranial nerve palsy plus other cranial nerve involvement in the cavernous sinus and proptosis with arterialized episcleral/conjunctival veins due to a large volume shunt of arterial blood into the anterior draining veins of the cavernous sinus. Isolated third cranial nerve involvement without the orbital congestion can occur when the primary drainage is posterior from the cavernous sinus, the so-called white eye fistulas. [5]

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