Neuro: Division of BS

Question 1

What are the 3 longitudinal divisions of the brainstem?

Answer 1

Basilar - front

Tegmentum - middle

Tectum - back

Question 2

The tectum is only found in the….

Answer 2

Midbrain

Question 3

What does the tectum consist of?

Answer 3

Superior + inferior colliculus and pretectum

Question 4

What is inside of the tegmentum

Answer 4

Reticular Formation

Sensory nuclei and ascending sensory tracts

CN V nuclei

Medial longitudinal fasciculus (coordinates head and eye mvmt)

Really Some Cool Moves

Question 5

What is inside of the basilar division?

Answer 5

descending axons from cerebral cortex, corticospinal, corticobrainstem, corticopontine, and corticoreticular tracts

Motor nuclei from substantia nigra, pons, and inferior olive

Basically a bunch of motor stuff (all tracts that start with cortico-)

pontocerebellar axons

Question 6

What is in the basis pedunculi?

Answer 6

Cerebral peduncles

substantia niagra nucleus

Question 7

What does the superior colliculus do?

Answer 7

motor and sensory info to orient head and eyes

Question 8

What does the inferior colliculus do?

Answer 8

relays info from cochlear nerve to superior colliculus and thalamus

Question 9

The pretectal area of the midbrain does what?

Answer 9

mediates eye reflexes

Question 10

What kind of matter is the red nucleus made out of?

Answer 10

Gray matter (part of cognitive and motor circuit)

Question 11

What cranial nerve nuclei are found in the midbrain tegmentum

Answer 11

3 and 4

Question 12

What 2 tracts synapse in the pons? Most of the tracts do not

Answer 12

corticopontine tract- Synapse on pontine nuclei -> pontocerebellar fibers -> middle cerebellar peduncle -> synapse in contralateral cerebellar hemisphere

corticobrainstem tract - synapses with trigeminal motor nucleus and facial nucleus

Question 13

What kind of fibers are in the superior cerebellar peduncle?

Answer 13

Sensory fibers

Question 14

What can you find in the basilar portion of the pons?

Answer 14

Descending tracts- corticospinal, corticobrainstem, corticopontine

Pontine nuclei

Pontocerebellar axons

Question 15

What can be found in the tegmentum of the Pons?

Answer 15

Sensory Tracts

Reticular Formation

Autonomic pathways

CN 5,6,7,8 nuclei

Question 16

What cranial nerve nuclei exits between the pyramid and inferior olive?

Answer 16

CN 12

Question 17

What is the nucleus ambiguus for?

Answer 17

Motor output to swallowing/vocalization muscles

(Which would be CN 9, 10, 12)

Question 18

What is the only tract that enters the medulla from the cerebellum

(The rest enter medulla -> inferior cerebellar peduncle -> cerebellum)

Answer 18

Cerebellovestibular tract

Question 19

The DCML crosses in the inferior medulla ________ to the crossing of the corticospinal tract

Answer 19

Posterior

Question 20

The anterior inferior cerebellar artery supplies the _____ whereas the Posterior inferior cerebellar artery supplies the _______

Answer 20

Pons

Medulla

Question 21

What are the 4 brain stem tracts?

Answer 21

Rubrospinal Vestibulospinal Reticulospinal Tectospinal

Question 22

What are the general brain stem functions

Answer 22

Modulates conciousness

Regulates vital signs

Conveys signal from cortex to spinal cord

Question 23

What are the 4 cardinal signs of brain stem dysfunction? 4 Ds

Answer 23

Dysphagia, Dysarthria, diplopia, dysmetria

Question 24

Damage to brain stem could cause….

Answer 24

Heart to stop beating

BP to fluctuate

Breathing to stop

Question 25

Disorders of conciousness are due to damage of_______

Answer 25

Reticular activating formation/ reticular formation People in vegetative or minimally concious states have loss of tissue in subcoritcal/thalamic/brainstem regions

Question 26

Anteriormedial midbrain syndrome (webers) is caused by….

Answer 26

Blockage of PCA or Basilar artery

Question 27

What are the primary structures affected by Anteromedial midbrain syndrome (webers)

Answer 27

Corticospinal tract- contralateral motor paralysis Occulomotor nerve nucleus- Ipsilateral loss of eye movements. Paralysis of eyelid, dilated pupil Red Nucleus- loss of motor coordination, ataxia, CONTRALATERAL, inappropriate laughing and crying. Lability

Question 28

What does CN3 palsy look like?

Answer 28

Eye deviated down and out

Question 29

Lateral inferior pontine syndrome is due to occlusion of the….

Answer 29

Anterior inferior cerebellar artery

Question 30

What are the clinical manifestations of lateral inferior pontine syndrome What artery?

Answer 30

Cochlear nucleus- ipsilateral hearing loss Vestibular nucleus affected- dysequilibrium, nausea, vomiting Impaired descending sympathetic- ipsilateral Horner’s syndrome Trigeminal nerve- ipsilateral pain and temp loss of face Salivatory nucleus- decreased tears and salivation Spinothalamic tract- contralateral pain and temperature sensation to body Facial nerve- ipsilateral loss of facial muscles Remember, Trigeminal, Facial, And Vestibulocochlear nerve are all on the pons and the pons is supplied blood by AICA

Question 31

Damage to what nerve causes Bell’s palsy How will Bell’s palsy differ from a facial weakness after stroke

Answer 31

Facial nerve Stroke is usually only lower facial weakness | (Upperface muscle preserved due to dual innervation of the upper face)

Question 32

What is Horner’s syndrome?

Answer 32

Miosis- pupil constricted Ptosis- drooping eye lid Anhidrosis- drying of skin in the area Damage to sympathetic nerves

Question 33

Locked in syndrome is due to damage of the….

Answer 33

Basiliar artery impacting the ventral pons bilaterally

Question 34

What are the primary structures involved in locked in syndrome-

Answer 34

B corticospinal tracts- paralysis below the head B corticobulbar tracts- paralysis of facial muscles B abducens tracts- unable to move eyes to side Note: most of the time cranial nerve 3 is preserved but sometimes its impacted

Question 35

What are spared in locked-in syndrome?

Answer 35

Reticular activating formation/ reticular formation Vertical gaze centers are spared.

Question 36

Middle medullary syndrome is caused by a blockage in the ….

Answer 36

Anterior spinal artery

Question 37

What is the 2nd most common place to have a stroke in the brainstem?

Answer 37

AICA

Question 38

What are the primary structures affected by medial medullary syndrome

Answer 38

hypoglossal nerve- ipsilateral tongue protrusion DCML- contralateral loss of DCML senses Lateral corticospinal- contralateral hemiparesis Remember the hypoglossal nerve comes off of the medial medulla!

Question 39

What is the most common brainstem stroke, and what artery causes it?

Answer 39

Lateral medullary syndrome (wallenberg) Due to blockage of PICA

Question 40

What structures are affected due to Wallenberg syndrome (lateral medullary syndrome)

Answer 40

Vagus nerve/Solitary nucleus- elevated HR Vestibular nucleus- balance Vagus nerve nucleus- altered vitals Trigeminal Nerve Inferior cerebellar peduncle - ataxia/coordination ipsilateral Salivatory nucleus - unable to salivate or make tears Spinothalamic tract- contralateral Descending sympathetic- ipsilateral Horner syndrome Nucleus ambiguus (9 10) and 12 cranial nerve. Tongue/ larynx/pharynx affected. Lack of gag reflex

Question 41

The reticular formation is in the _______ of the pons

Answer 41

tegmentum