Brainstem and Cranial Nerves Flashcards
What CN exits the brainstem dorsally?
CN IV
What CN go through the superior orbital fissure?
CN 3, 4, v1, 6
CNs at cerebellopontine angle?
7, 8, 9
CNs through jugular foramen?
9, 10, 11
CNs from midbrain and path
3: from interpeduncular fossa between PCA and superior cerebellar a.
4: from dorsal midbrain and crosses
CNs in pontomedullary junction?
CN VI
CN located at pons?
CN V, at Meckel’s cave near cavernous sinus
what are the exit points for the trigeminal nerve branches out of skull?
V1: superior orbital fissure
V2: foramen rotundum
V3: foramen ovale
Trigeminal sensory system required for propioception of face and jaw jerk?
Mesencephalic
trigeminal system for fine touch and dental pressure, and what path to what thalamic nuclei?
Chief trigeminal sensory in trigeminal lemniscus to VPM
trigeminal system for crude touch, pain, temp. path and thalamic nuclei?
Spinal trigeminal: trigeminothalamic tract to VPM
what does the facial nerve loop around?
abducens nuclei forming facial colliculus on floor of 4th ventricle
taste anterior 2/3 of tongue?
CN 7
sensation, anterior 2/3 tongue?
V3
superior olivary complex of pons involved in what?
hearing sound localizations
inferior colliculi involved in?
hearing
superior colliculi involved in?
mostly vision
what special sense is associated with MGN?
auditory
posterior 1/3 tongue for taste and sensation?
CN IX (9)
nucleus where the chemo/baroreceptors of carotid and aortic arch?
nucleus solitarus caudal
nucleus where the taste of back of tongue and throat go?
nucleus solitarus rostral/gustatory
nucleus for swallowing / voice
nucleus ambuiguus
nucleus for parasympathetics of vagus?
dorsal motor nucleus of CN X
UMN vs LMN of XI?
UMN involves prob w/ head turn to opposite side only
LMN involves both head turn and shoulder shrug
LMN lesion of hypoglossal causes what?
ipsilat tongue weakness with deviation to the side of damage
Name the four nuclei involved in parasympathetic brainstem cranial nerve functions
- edinger-westphal 3
- superior salivary 7
- inferior salivary 9
4 dorsal motor nucleus of vagus
what is foster kennedy syndrome and what causes it?
anosmmia and optic atrophy with papilledema in other eye due to tumor compression under base of frontal lobe like meningioma, sarcoid, mets
what is glomus jugulare?
tumors of globus bodies in jugular foramen causing CN ix, x, xi problems and you can see a fleshy vascular mass sometimes on ear exam
location when there is gelastic epilepsy?
hypothalamic
risk of what vision loss with prolonged spinal or cardiac surgery?
posterior ischemic optic neuropathy
optic neuropathy seen in older patient with acute onset, limited recovery and altitudinal defect w/ optic disc swelling assoc w/ CV risk factors?
anterior optic neuropathy
what type of optic neuritis spares the nerve, 2 major causes
perineuritis due to optic sheath demyelination, usu caused by infection/syphilis or sarcoid
what other tests / other organs to consider in adolescent male with vision loss, what dz?
Lebers, EKG for AV conduction pathway defects
muscles involved in mild eye opening (mild ptosis) and also some mild pupil dilation
muller muscles (Tarsal) (has some sympathetic to dilate eyes) NOT levator palpebrae which is involved in major eye opening
what is Collier’s sign and what is it seen with?
Convergence and eyelid retraction, seen with nuclear lesions/Parinaud’s syndrome
lesion causing ipsilateral CN3 palsy, contralateral hemiplegia
- syndrome
- location
Weber’s syndrome
base of midbrain catching CNIII fibers and CST
type of deficits (side) in most brainstem lesions
ipsilat
clinical syndrome with
ptosis, inability to look up, convergence retraction
3 major causes
where is the lesion
dorsal midbrain/periaqueductal grey Parinaud's syndrome- gets the nucleus -children with hydrocephalus -MS -pineal gland tumors
ipsilat CN 3 palsy
contralateral ataxia and tremor
Syndrome and location
involves CNIII and RED nucleus (fibers to cerebellum) -
middle of midbrain
Claude/clutzy syndrome
ipsilat CN3, contralat tremor and hemiplegia
Syndrome and location
Benedikt: gets red nucleus, CNIII fibers, AND CST
think shaky/old/can’t move or see benedict
where is the location of lesion in patient with pupillary dilation and poor response to light, but preserved convergence and with CNIII palsy?
uncal herniation - Hutchinson pupil
sympathetic eyes
dilated
parasympathetic eyes
constricted (think of CN3 blown pupil)
upper face sensory changes and can’t move eyes?
Cavernous sinus lesion
sensory changes in upper face, can’t move eyes, AND can’t see?
Cavernous sinus involving orbital apex: orbital apex syndrome
what is Tolosa Hunt
cavernous sinus inflammatory granuloma syndrome
aneurysm causing CNIII palsy
PCOMM
vertical diplopia worse on downgaze (can’t read or walk down steps)
Trochlear neuropathy
head tilt in trochlear palsy?
head tilt away from palsy
where do trigeminal sensory face fibers go in thalamus?
VPM (m = face MAsk)
what happens if you lesion the trigeminal nerve NUCLEUS
onion circle of sensory loss on face (before you branch into the different trigeminal divisions)
horizontal gaze disturbance and facial diplegia sometimes with other malformations?
Mobius syndrome
duane syndrome is what
CNVI nuclei aplasia
ipsilat CN6 palsy, ipsilat facial weakness, and contralateral hemiparesis
Where is the lesion
Millard Gubler syndrome: pontine lesion
JUST MOTOR
ipsilat horizontal gaze palsy with facial weakness and contralat hemiparesis and ALSO contralat sensory loss AND INO
Lesion and cause?
lesion is in pons involving sensory and motor in FOVILLE syndrome
Due to AICA infarct often
can’t adduct one eye. Other eye has nystagmus. Able to adduct with convergence
What is it and where is lesion
INO, MLF
INO in one direction and convergent palsy of gaze in the other direction
what is it and where is the lesion
one and a half syndrome
PPRF and MLF
CN VII nucleus for smooth muscle and glands for lacrimation?
superior salivatory nucleus
CNVII nucleus for taste
where are the cell bodies?
Tractus solitarius with cell bodies in geniculate ganglion
what makes the nervus intermedius in the CN VII?
sensory fibers from
- superior salivatory nucleus for glands AND
- tractus solitarius for taste
What does the Intermedius nerve join and where for CN VII
joins the motor nucleus fibers in the internal auditory canal and all go together en route to geniculate ganglion
what branches comes off as pathways of CNVII after the geniculate ganglion and their function
- Greater petrosal nerve (glands)
- Stapedius (dampens sound)
- chorda tympani (taste)
- stylomastoid foramen (facial expression)
where is the geniculate ganglion located CN VII
internal auditory canal
Treatment of classic Bell’s
Prednisone alone
If you have a Bell’s with sensory changes on face or hearing loss
think what lesion? and what possible causes?
CP angle involving 5, 7, and 8.
Schwannoma or meningioma
what is Meige syndrome
idiopathic bletharospasm, can’t open eyes, contractures of orbicularis oculi muscles.
oromandibular dystonia
sustained grimace of mouth and neck flexion
patient can’t open eyes b/c orbicularis oculi is contracted
three causes?
- Meige syndrome
- MS
- Multisystem atrophy
CP angle cranial nerves
5, 7, 8 involvement
What is Cogan syndrome?
Tx
chronic inflammatory dz in young white males involving CN VIII causing hearing loss, vestibular symptoms and keratitis
Tx w/ steroids
Meniere disease triad?
unilateral hearing loss to low frequencies
tinnitus
vertigo, episodic
eye issues in NF2
cataracts
sharp, unilateral stabbing pain in throat, tongue or ear w/ chewing or talking in 40-60 yr old
Dx and tx?
glossoparhyngeal neuropathy
Tx w/ carbamazepine
5 nuclei of glossopharyngeal nerve and function
- solitary nucleus: taste, autonomic (carotid)
- spinal nucleus of V: postauricular skin, inner TM
- mesencephalic nucleus of V: sensory of stylopharyngeus (proprioception)
- ambiguous nucleus: motor for pharynx
- inferior salivatory nucleus: parotid
What are the four nuclei of CN X and function?
- Spinal nucleus of V: sensation to external ear, external TM, auditory canal
- Solitary nucleus (visceral)
- nucleus ambiguus: striated muscle and sensory below vocal cords for recurrent laryngeal nerve
- dorsal motor nucleus of X: smooth muscle
which direction does the uvula go with CN X lesion
AWAY from lesion
recurrent laryngeal nerve most likely to be injured
left
What is Wallenberg syndrome
PICA/vertebral artery - Lateral Medullary Syndrome
-nystagmus vertigo N/V
-sensory: loss of pain/temp of face
-contralat sensory pain/temp body
-ipsilat Horners
-ipsilat paralysis of palate/vocal cord
NO MOTOR: only cerebellar, sensation, sympathetic
spinal accessory nerve enters and exits skull how?
enters through foramen magnum (fibers from cord and medulla)
exits through jugular foramen
which way does head turn with supranuclear and infranuclear spinal accessory nerve damage? Shoulder issue?
Supranuclear: head turn toward lesion and away from weak limb (like in stroke to lesion vs sz)
Infranuclear:
Trapezius: weak ipsilat shoulder shrug (hangs lower)
SCM: head turns toward lesion weak to turn away
what is Vernet’s syndrome?
Jugular foramen syndrome
-CN 9. 10 11
isolated winged scapula from what
isolated spinal accessory neuropathy - arm can’t be abducted past the horizontal/90 degree plane
supranuclear vs infranuclear tongue deviation with hypoglossal nerve lesion
supranuclear: tongue goes to the side of limb weakness (contralat to lesion)
infranuclear: tongue goes to the lesion side
*clue: Lower motor neuron tongue could Lick the Lesion
what is dejerine’s anterior bulbar syndrome?
occluded anterior spinal artery or parent vertebral artery
causes:
1. ipsilateral tongue involvement toward lesion
2. contralat hemiplegia SPARING face
3. contralat position/vibratory sensation loss
what is collet-sicard syndrome
damage to hypoglossal nerve and jugular foramen w/ 5 features
Think of Vernet syndrome AND CN 12
- trapezius/SCM ipsilat paralysis
- vocal cord/pharynx weakness
- tongue paralysis
- loss of posterior tongue taste
- hemianesthesia of palate pharynx larynx
nuclei of CN V (4)
- Main sensory (fine touch)
- Mesencephalic (position) *located in CNS not peripheral ganglia
(Me’s in cephalic: position) - motor
- spinal (pain/temp)
ventral trigeminothalamic tract what is it?
pain/temp from face/mouth
-people vent when in pain
what does the dorsal trigeminothalamic tract do?
carries touch/pressure from face (think dorsal columns)
where do sensory facial fibers go in internal capsule
posterior limb
where does the CN VII exit the brainstem and skull
brainstem out cerebellopontine angle
exits skull through stylomastoid foramen
5 branches of facial nerve and muscle innervated
- buccal: buccinator
- cervical: platysma
- mandibular: orbicularis oris
- temporal: frontalis
- zygomatic: orbicularis oculari
central tegmental tract for what
nucleus tractus solitarius to CPM for taste
ramsay hunt syndrome
herpes zoster oticus
cell bodies of cochlear nerve are located where?
spiral ganglion in temporal bone
main motor nucleus of CN IX?
nucleus ambiguus
sensory nucleus of CN IX
nucleus of the tractus solitarius
parasympathetic functions of CN IX go to what nucleus?
inferior salivary nucleus
orbital apex vs superior orbital fissure lesion vs cavernous sinus syndrome
all have 3, 4, 6, V1
Orbital apex also has 2
Cavernous sinus also has V2
