cranial nerve palsy CN3

Chief complaint: Double vision

History of Present Illness: 61 year old female with history of HTN, DM, hyperlipidemia, and chronic low back pain presenting with double vision. She received an epidural spinal injection yesterday for the 4th time for low back pain. She was sedated for the procedure and woke up with headache, neck stiffness, and left eye “jumping around,” which progressed to double vision 1 hour later.

There was no blurry or double vision with either eye closed. She had 1 episode of emesis. She presented to the ED 24 hours later with continued headache and double vision.

General: Well-appearing, no acute distress


  • Right eye: Ptosis, mydriasis, and limited elevation, adduction, and depression of eye; no relative afferent pupillary defect
  • Left eye: Normal

Cardiac: Normal S1, S2; no murmur

Pulmonary: Normal chest excursion with respiration; lungs clear bilaterally

Abdominal: Soft non-distended, non-tender

Neurologic: 5/5 strength bilateral upper extremities and lower extremities; sensation intact; finger to nose normal

CBC: WBC 12.4, Hgb 13.4, platelet 222

BMP: Na 138, K 4.5, Cl 100, CO2 24, BUN 19, Cr 1.0

Thyroid function tests: Within normal limits

Right cranial nerve III palsy

Image 1: Leftward gaze demonstrating incomplete adduction of right eye and ptosis noted to right eyelid. There is also mydriasis although it is not clearly shown in the photo.

Image 2: Upward gaze and demonstrates incomplete elevation of the right eye.

Image 3: Intracranial air anterior to brainstem (pneumocephalus)

Pneumocephalus after epidural injections is a rare complication of a common procedure. Only a few cases are reported per year.

Unintentional dura puncture causes air to be introduced into the subarachnoid/subdural space and migrates intracranially, and may cause a headache. It is possible that there is cranial nerve III compression as it exits the brainstem.

Take Home Points

  • CN III palsy can present with the following:
    • Ptosis
    • Dilated and poorly reactive to nonreactive pupil
    • Paresis or paralysis of ocular adduction, elevation, and depression.
  • Pneumocephalus is a rare complication of epidural injections.
  • Treatment of pneumocephalus may include 40-100% oxygen and admission for observation, if symptoms are severe.
Richard Wang, MD

Richard Wang, MD

Emergency Medicine
Maimonides Medical Center
Richard Wang, MD

Latest posts by Richard Wang, MD (see all)

Leily Naraghi, MD

Emergency Medicine Faculty
Maimonides Medical Center

Latest posts by Leily Naraghi, MD (see all)