Brain Stem Flashcards
motor CN exit point
midline
mixed CN exit point
lateral
rostral pons lesions –> which CN
V
caudal pons lesions affect…
may only affect VI, VII, VIII
CST lesion in BS Sx
(UMN above decussation)
spastic weakness contra and below
ML lesion in BS Sx
(2nd neuron)
loss of touch, vibration contra and below
STT lesion in BS Sx
(crossed in spinal section)
pain/temp loss contra and below
DHF lesion in BS Sx
ipsilateral central horner’s syndrome
sulcus limitans
line btwn motor and sensory in spinal cord and brain stem
neural tube to brain stem orientation
NT: sensory = dorsal; motor = ventral
BS: sensory = lateral; motor = medial
motor nuclei in midbrain
oculomotor
edinger westphal
trochlear
sensory nuc in midbrain
mesencephalic nuc of V
motor nuclei in pons
abducens
superior salivitory
motor trigeminal
motor facial
sensory nuc in pons
principle sensory nuc of V
spinal trigeminal
motor nuc in medulla
hypoglossal
inferior salivatory nuc
dorsal motor nuc
nuc ambiguus
sensory nuc in medulla
solitary
vestibular
cochlear
spinal trigeminal
most medial motor nucs
oculomotor (III)
trochlear (IV)
abducens (VI)
hypoglossal (XII)
most medial motor nuc (fxn - broad)
skeletal muscle
cell bodies of LMNs
most medial motor nuc axon location
axons exit same section
oculomotor path/exit
nuc
ant and medial
exit midbrain
ipsilateral
trochlear path/exit
nuc go around cerebral aquaduct cross at troch decussation exit posterior medial midbrain contralateral
abducens path/exit
nuc
ant medial
exit pons
ipsilateral
hypoglossal path/exit
nuc
go ant
exit medulla
ipsilateral
medial longitudinal fasciculus
connect oculomotor nuc and abducens nuc for vestibular system
most medial motor nuc (fxn - specific)
III (adduct eye, raise eyelid)
IV (depress, abduct, intort eye)
VI (abduct eye)
XII (move tongue)
motor nucs in between medial and lateral (2nd vertical row)
nuc of edinger westphal (III)
superior salivatory nuc (VII)
inferior salivatory nuc (IX)
dorsal motor nuc of X
motor nucs in between medial and lateral (fxn - broad)
parasympathetic
preganglionic
motor nucs in between medial and lateral (fxn - specific)
NucEW III (pupil constriction, near response)
SupSalv VII (lacrimal, salivary, submandibular)
InfSalv (parotid)
DorMot (gut)
most lateral motor nucs
motor nuc of V
motor nuc of VII
nuc ambiguus (IX, X*)
most lateral motor nuc (fxn - broad)
pharyngeal arch motor
skeletal LMNs
most lateral motor nuc (fxn -specific)
motor nuc of V (mastication)
motor nuc of VII (facial expression)
nuc ambiguus (palate, pharynx, larynx)
motor nuc of V path/exit
nuc
out laterally
exit midbrain
ipsi
motor nuc of VII path/exit
nuc go medial/superior loop around abducens nuc go lateral inferior combine with sup salv exit pons (laterally) as facial nerve ipsi
nuc ambiguus path/exit
nuc
1/2 combine w/ dorsal motor of X - exit medulla laterally as vagus nerve
1/2 combine w/ inf salv - exit medulla laterally as glossopharyngeal
ipsi
most medial sensory nucs
solitary nuc
most medial sensory nuc (fxn)
taste (VII, IX, X) carotid sinus (baro) and body (chemo) (IX, X)
sensory nuc btwn medial and lateral
vestibular nuc (VIII) cochlear nuc (VIII)
most lateral sensory nucs
mesencephalic nuc
main/chief/principle nuc
spinal nuc
most lateral sensory nucs (fxn - broad)
trigeminal nucs
most lateral sensory nucs (fxn - specific)
mesencephalic (proprioception)
main (touch)
spinal (pain/temp)
midbrain CNs
III
IV
pons CNs
V (rostral)
VI
VII
VIII
medulla CNs
IX
X
XII
brain stem lesion qualities
all contra except Horners (DHF)
berry aneurysms where?
branch @ ant communicating
branch @ posterior communicating
midbrain circ
posterior cerebral
pons circ
medial - paramedian
lateral - AICA
medulla circ
medial - ant spinal
lateral - PICA
medial medullary syndrome affected areas
pyramid
ML
XII fibers
medial medullary syndrome defects
pyramid: contra spastic (hyper reflex, toes up)
ML: contra t/v/p
XII: deviate to lesion side (ipsi)
medial medullary syndrome vessel
anterior spinal artery
lateral medullary syndrome vessel
PICA
lateral medullary syndrome AKA
Wallenberg syndrome
lateral medullary syndrome affected areas
ICP spinal tract of V STT vestibular nuclei DHF nuc ambiguus (IX, X)
lateral medullary syndrome defects
ICP: ipsi limb ataxia
spinal V: ipsi p/t face
STT: contra p/t body
vestibular nuclei: vomiting, vertigo, nystagmus (away from lesion)
DHF: horner (ipsi)
nuc ambiguus: ipsi vocal paralysis, dysphagia, palate droop, no gag (IX)
ventral midbrain syndrome vessel
post cerebral artery
ventral midbrain syndrome AKA
Weber syndrome
ventral midbrain syndrome affected areas
CST
CBT
III
ventral midbrain syndrome defects
CST: contra spast (mostly UL)
CBT: contra spastic lower 1/2 face
III: ipsi oculomotor palsy (dilated pupil, ptosis, downa nd out)
lateral strabismus
eye turned down and out as result of lesioned III
spinal cord tract lesions (ipsi vs contra)
DC: ipsi t/p/v
CST: ipsi spastic
STT: contra p/t
brainstem lesions (ipsi vs contra)
long ttracts –> contra (except horners)
CN –> ipsi