Neurological Conditions Flashcards
Name cranial nerve VI
Abducens
What muscle does CN VI supply?
Lateral rectus muscle
How will patients with a CN VI palsy present?
Unable to abduct their eye properly and it will turn inwards in primary position
What causes a CN VI palsy?
> 50 years old - microvascular pathology
<50 years old - increased ICP, tumour, congenital, demyelination
Why is CN VI susceptible to compression?
It travels over the petrous apex of the temporal bone right next to the brain
Name cranial nerve IV
Trochlear
What muscle does the trochlear nerve supply?
Superior oblique
How will a patient with a CN IV palsy present?
Abnormality on depression in adduction and eyes will lie at the wrong angle (weak incyclo-torsion)
How will patients compensate for the weak incyclo-torsion?
Tilt their head
What causes a CN IV palsy?
Most common - congenital
Microvascular, tumour, closed head trauma
Why is CN IV susceptible to damage?
It is long and thin
Name cranial nerve III
Oculomotor
How will patients with a CN III palsy present?
Down and out ocular position with a dilated pupil and ptosis
What can cause a CN III palsy?
Aneurysm, tumour, microvascular pathology, MS, congenital
What is the significance of a dilated pupil in suspected CN III palsy?
If the pupil is involved this signifies peripheral compression on the nerve and more serious pathology. If pupil is normal then microvascular pathology is most likely.
