Eye movement and pupillary control Flashcards
which eye movements are possible by the oculomotor nerve?
elevation of upper eyelid
upward and downward movements
adduction
upward and abduction
complication of oculomotor palsy
are unilateral and ipsilateral to lesion
bleapharoptosis, only abduction, strabismus (divergent), horizontal diplopia, mydriasis
causes of oculomotor palsy
inside brainstem:
- nucular palsies (alcoholics, undernourishment, weight loss surgery, AIDS, ethanol intoxication)
- extranucular palsies (vascular cause: DM, neurosyphillis)
- other (Wernicke’s encephalopathy, demyalinative and inflammatory lesions, tumors, cerebral hemorrhage )
outside brainstem:
- aneurysm (PCA, post. commun. art., post-sup cerebellar art), infections, inflammations, neoplasm
what could a cavernous sinus thrombosis cause on ocular level?
complete ophtalmoplegia, chemosis, eye pain
which eye movements are possible by the trochlear nerve?
what type of nerve is IV nerve?
is a pure motor nerve, has long pathway and easily injured by trauma and intracranial HTN
downward gaze and abuction of eye
complication of trochlear palsy
upward gaze and adduction, vertical diplopia
causes of trochlear palsy
ischemic nuclear lesion congenital paralysis inflammatory lesions and tumors meningitis cavernous sinus thrombosis
which eye movements are possible by the abducens nerve?
what type of nerve is VI nerve?
is a pure motor nerve
abduction of the eye
complications of abducens nerve palsy
convergent strabismus
cant do abduction
horizontal diplopia
causes of abducens palsy
inside brainstem: vascular causes
outside brainstem: trauma, infections, inflammations, neoplasm, intracranial HTN