Howard's Anatomy Flashcards
olfactory N
bulb/N are under frontal lobe= often damaged in acc/deceleration injury. prob in smell affects taste. only sensory modality that bypass thalamus.
anosmia
early sign of parkinson’s disease- smell tests are used as screen
CN3 lesion
ptosis (bc ctrl elevator palpebral superiors). eye deviated downward and outwards
imaging for CN3 palsy
order MRA bc there could be aneurysm of ipsilateral posterior communicating artery
superior oblique M
pulls N down and interest eye. only CN that decussates. Right CN4 innervates left superior oblique.
PSNS eye
in edinger westphal nucleus in brainstem.
pupil sparing third
ex microvascular disease from diabetes.
CN3 location
emerge from brainstem btw posterior cerebral A and superior cerebellar A. run under posterior communicating A.
CN4 location
only CN that exits from dorsal aspect of brainstem
CN4 damage
causes vertical diplopia and pt compensate by tilting head towards shoulder on the unaffected side= side of lesion. can be due to trauma
Cavernous sinus contents
O TOM CAT: oculomotor nerve, trochlear N, ophalmic branch of CN5, maxillary branch of CN5, internal carotid A, abducent N. O TOM are lateral wall components from superior to inferior. CA ends at lvl of T from O TOM.
Cavernous sinus location
lateral to sella turcica. border by temporal and sphenoid bones
pineal gland
secretes melatonin. stimulated by darkness, inhibited by light. usually calcified.
melatonin
help reg sleep/wake cycle.
pinealomas
silent until affect midbrain –> visual sx. up gaze. circadian rhythm disruptions. most common type in germinomas.
frontal eye fields
cortical areas that ctrl eye mvt. deviate eye to pop direction. ban in here produce gaze preference
horner’s syndrome
ptosis, miosis, anhydrosis/ common in carotid dissection and vertebral artery dissection as part of wallenberg syndrome
internuclear opthalmoplegia
look right. cannot adduct left eye. abducting nystagmus of right eye. conference preserved. due to lesion in medial longitudinal fasciculus which connect CN3 and CN6. most often seen in MS
optic neuritis
give 3d IV steroids then oral taper. hasten recovery, delay 2nd demyelinating epic but no long term impact on disease. loss of color vision, particularly red. severe relapses treated with plasmapheresis
afferent pupillary defect: due to. evaluate by
due to lesion to CN2. evaluate with swinging flashlight test. direct response is impaired. consensual response preserved. so when light on good eye, both constrict. eventual optic pallor.
clinical disability in MS correlates most with
black holes (permanent axonal damage) and atrophy
Uhthoff’s phenomena
tendency heat worsen MS sx
MS associated with
def in Vit D incr risk of dev MS. less common in areas near equator. higher it D- fewer relapses. Epstein-barr virus
MS etio
1/750. most white females (3:1), 30s. far from equator. move bf age 15- dev risk of new home.