Download 3rd nerve palsy

3RD NERVE PALSY
OCULOMOTOR
3RD CRANIAL NERVE SUPPLIES:
1) Levator palpebrae superioris
2) 4 out of 6 Extra-ocular muscles
a. Superior Rectus
b. Inferior Rectus
Ie: NOT: Lateral rectus, Superior Oblique
c. Medial Rectus
d. Inferior Oblique
3) Parasympathetic fibres to pupil (from EW nucleus constricts) = run
SUPERFICIALLY
FAILURE/LESION:
Unilateral Ptosis
Eye moves DOWN & OUT = diplopia
Pupil: DILATION = suggests COMPRESSION
No Sensory fibres
Circle of Willis
Lies directly superiorly to 3rd Nerve
PCA aneurysms (at origin from ICA)  compress 3rd nerve
 Angiography required for all Isolated 3rd Nerve palsies with pupil dilation
Basal meningeal infection/tumor
Can also compress 3rd nerve
Cavernous sinus:
3rd nerve superior & lateral in sinus
Pupil may be unaffected
Cavernous thrombosis, carotid aneurysm, malignancy (pituitary),