Third nerve palsy: Difference between revisions
(Created page with "== Background == *Third (oculomotor) nerve, innervates eyelid muscles and external ocular muscles (except lateral rectus and superior oblique) *Nerve also carries parasympathe...") |
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== Causes == | == Causes == | ||
* | *Posterior Communicating Artery Aneurysm | ||
**Compresses nerve | **Compresses nerve | ||
*Ischemia | *Ischemia | ||
| Line 14: | Line 14: | ||
*Trauma | *Trauma | ||
**Temporal lobe herniation through tentorium | **Temporal lobe herniation through tentorium | ||
*Myasthenia Gravis | *[[Myasthenia Gravis]] | ||
*[[Cavernous Sinus Thrombosis]] | |||
**often associated with other cranial nerve defecits | |||
*Neurosyphillis | |||
*Autoimmune vasculitis ([[Systemic Lupus Erythematosus|Lupus]] | |||
== Clinical Features == | == Clinical Features == | ||
Revision as of 04:35, 15 January 2014
Background
- Third (oculomotor) nerve, innervates eyelid muscles and external ocular muscles (except lateral rectus and superior oblique)
- Nerve also carries parasympathetic fibers on external surface allowing for pupillary constriction
- Palsy causes diplopia except in lateral gaze (lateral rectus innervated by CN VI)
- Ptosis, headache
Causes
- Posterior Communicating Artery Aneurysm
- Compresses nerve
- Ischemia
- Diabetes
- Trauma
- Temporal lobe herniation through tentorium
- Myasthenia Gravis
- Cavernous Sinus Thrombosis
- often associated with other cranial nerve defecits
- Neurosyphillis
- Autoimmune vasculitis (Lupus
Clinical Features
- Eye deviates laterally and down
- Pupil exam:
- If dilated/nonreactive likely secondary to space occupying lesion
- If pupil is spared likely ischemic etiology
- Loss of accommodation
DDx
- Aneurysm
- Carotid Cavernous Fistula
- Mass
- Ischemia
Work-up
- CT/CTA head
- MRI/MRA head
- Cerebral Angiography
Dispo
- If ischemic cause
- Medical management with most self resolving in 6-8 wks
- Ophthalmology f/u
- If aneurysm/mass
- Neurosurgery consult
- If diplopia, no driving or operating heavy machinery
Source
Harwood and Nuss, Rosen's, Emedicine