Individual cranial nerve palsies Flashcards
What is 3rd nerve palsy?
Paralysis of the oculomotor nerve
What eye muscles does the ocular motor never supply?
All except superior oblique (trochlear) and lateral rectus (abducens)
What is surgical 3rd nerve palsy vs medical 3rd n palsy?
Surgical- refers to compressive lesions whereas medical refers to non- compressive lesions
E.g. of surgical 3rd N palsy?
Posterior communicating artery aneurysms, cavernous sinus lesions
Example of medical 3rd n palsy?
MS, vascular causes e.g diabetes or hypertension or vasculitis
Presentation of 3rd n palsy?
Eye is down and out
Double vision
Ptosis
Proptosis
Fixed pupil dilatation (surgical)
What is 4th nerve palsy?
Paralysis of trochlear n which controls the superior oblique muscles
What is the function of superior oblique?
Pull eye to look down and in
How do pts present with 4th n palsy?
Double vision worse in the vertical plane
Potential hypertrophic
Tilted head to compensate
What are the causes of 4th n palsy?
idiopathic,
Ocular trauma
and DM/ vascular cause
What is the 6th n palsy?
Paralysis of the abducens n which controls lateral rectus
What does lateral rectus do?
abduct the eye horizontally away from the midline
How do pts present with 6th nerve palsy?
Double vision worse in the horizontal plane
What is a ‘false localising sign’ in relation to 6th nerve palsy?
Raised ICP may cause the features of this palsy, when in fact the 6th N is intact- hence ‘false localising sign’
What are the causes of 6th nerve palsy?
Diabetic neuropathy
Stroke
Infection
Trauma
What is Bell’s palsy?
Idiopathic syndrome affecting facial N (CNVII)
How does Bell’s palsy present?
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)
Management of Bell’s palsy?
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
What is Bell’s phenomenon?
If eyelid closes, eye rolls back to protect the cornea
What points towards Ramsey Hunt vs Bells palsy?
Prominent otalgia
Vesicular rash in the external auditory meatus, palate or tongue
