Isolated nerve palsies - CN3, CN6 Flashcards
1
Q
What are the common examination findings?
A
Inspection
- 3rd nerve - Ptosis, pupil down and out, mydriasis
- 6th nerve - Affected eye adducted
Acuity
- 3rd nerve - Normal
- 6th nerve - Normal
Fields
- 3rd nerve - Normal but limited by ptosis
- 6th nerve - Normal
Pupils
- 3rd nerve - Dilated
- 6th nerve - Normal
Movements
- 3rd nerve - Can only intort and abduct
- 6th nerve - No abduction, double vision when looking to side of lesion
2
Q
What are the investigations?
A
To finish the exam i would like to do - Upper/lower limb exam and cranial nerves
By the bed - History, obs
Bloods - Glucose, B12, ANCA,ANA, anti cholinergic receptor antibodoes
Other - CT head, carotid doppler
3
Q
What are the key investigation findings?
A
Depends on cause
NB PCA aneurysm with CN3 palsy
4
Q
What is the treatment?
A
- Conservative - Education
- Treat underlying cause
5
Q
What are the common causes?
A
3rd nerve - Many Medics Diagnose Third Palsy
- Multiple sclerosis
- Myasthenia gravis
- Diabetes mellitus
- Trauma
- Posterior communicating artery aneurysm
6th nerve - Has a long cause so susceptible
- Raised ICP eg tumour
- MS
- Cavernous sinus lesions
6
Q
What are some causes of ptosis?
A
MG
Horners
CN3 palsy
