Nerve Palsys Flashcards
How does superior oblique attach to eyeball?
Attaches to superior aspect of eye coming from an anterior direction due to turning at trochlear
When contracts, will pull at top of eyeball and cause eye to look down and out
What is compensated CNIV palsy?
Patient tilts head away from side that has palsy to get eye to be in and down like the SO should be doing
What muscle does CNVI control?
Lateral rectus
In a CNVI palsy, what will the patient be unable to do?
Abduct the eye
What does CNIII supply?
Medial rectus Superior rectus Inferior rectus Inferior oblique Levator palpebrae superioris
Commonest cause of CNIII palsy and why?
Aneurysm causing compression because close to circle of Willis
What is the name of CNIV?
Trochlear
How will a CNIV nerve palsy present?
Eye will sit adducted, not massively obvious though
Eye will be unable to look in and down
Patient will have double vision
Patient may compensate by tilting their head
What is the name of CNIII?
Oculomotor
What does CNIV supply?
Superior oblique
What investigations should be done for nerve palsy in the eye?
Medical and neurological examination
Bloods
MRI - gold standard
What is the most common cause of Abducens nerve palsy?
Raised ICP as the nerve passes a bony feature called petrous tip which it can be compressed against
How will a CNIII nerve palsy eye look?
Will be looking down and out due to unopposed lateral rectus and superior oblique
How does inter-nuclear opthalmoplegia present?
Nystagmus in one eye when performing eye movements
What are the main causes of nerve palsy in the eye?
Tumour Microvascular Trauma Aneurysm Congenital MS/stroke Raised ICP
