Individual cranial nerve palsies

Question 1

What is 3rd nerve palsy?

Answer 1

Paralysis of the oculomotor nerve

Question 2

What eye muscles does the ocular motor never supply?

Answer 2

All except superior oblique (trochlear) and lateral rectus (abducens)

Question 3

What is surgical 3rd nerve palsy vs medical 3rd n palsy?

Answer 3

Surgical- refers to compressive lesions whereas medical refers to non- compressive lesions

Question 4

E.g. of surgical 3rd N palsy?

Answer 4

Posterior communicating artery aneurysms, cavernous sinus lesions

Question 5

Example of medical 3rd n palsy?

Answer 5

MS, vascular causes e.g diabetes or hypertension or vasculitis

Question 6

Presentation of 3rd n palsy?

Answer 6

Eye is down and out
Double vision
Ptosis
Proptosis
Fixed pupil dilatation (surgical)

Question 7

What is 4th nerve palsy?

Answer 7

Paralysis of trochlear n which controls the superior oblique muscles

Question 8

What is the function of superior oblique?

Answer 8

Pull eye to look down and in

Question 9

How do pts present with 4th n palsy?

Answer 9

Double vision worse in the vertical plane
Potential hypertrophic
Tilted head to compensate

Question 10

What are the causes of 4th n palsy?

Answer 10

idiopathic,
Ocular trauma
and DM/ vascular cause

Question 11

What is the 6th n palsy?

Answer 11

Paralysis of the abducens n which controls lateral rectus

Question 12

What does lateral rectus do?

Answer 12

abduct the eye horizontally away from the midline

Question 13

How do pts present with 6th nerve palsy?

Answer 13

Double vision worse in the horizontal plane

Question 14

What is a ‘false localising sign’ in relation to 6th nerve palsy?

Answer 14

Raised ICP may cause the features of this palsy, when in fact the 6th N is intact- hence ‘false localising sign’

Question 15

What are the causes of 6th nerve palsy?

Answer 15

Diabetic neuropathy
Stroke
Infection
Trauma

Question 16

What is Bell’s palsy?

Answer 16

Idiopathic syndrome affecting facial N (CNVII)

Question 17

How does Bell’s palsy present?

Answer 17

Acute onset unilateral, LMN facial weakness, sparing extra ocular muscles and muscles of mastication

Mild- moderate post auricular otalgia

Hyperacusis

Nervus intermedius syndrome (altered taste and dry eyes/mouth)

Question 18

Management of Bell’s palsy?

Answer 18

Oral steroids: 50mg OM for 10 days followed by taper
Supportive treatment: artificial tears, ocular lubricants, and eye patch esp if protective Bell’s phenomenon is absent

Question 19

What is Bell’s phenomenon?

Answer 19

If eyelid closes, eye rolls back to protect the cornea

Question 20

What points towards Ramsey Hunt vs Bells palsy?

Answer 20

Prominent otalgia
Vesicular rash in the external auditory meatus, palate or tongue