Blood Supply to Brainstem- Wilson Flashcards
Cortical or capsular lesion will cause what kind of signs?
contralateral hemisensory loss
contralateral hemiparesis
contralateral paresis lower half of face & tongue (corticobulbar)
Note: not alternating signs
Brainstem lesions have what kind of signs?
looking for alternating signs!!!
Ipsilateral to lesion
-Cranial nerve paralysis
(identifies level & laterality of lesion in brain stem)
-Horner’s syndrome
Contralateral to lesion
- hemiparesis
- hemisensory loss
- fine touch
- pain & temperature
Spinal cord hemisections will have what kind of signs?
No cranial nerve signs
No signs in head (ipsilateral Horner’s?
all the symptoms will be in the body trunk
only cranial nerve signs will be ipsilateral Horner’s syndrome
Ipsilateral Signs
(Below Lesion)
-Dorsal Column signs
-Motor loss
Contralateral signs (2 segments below lesion) -loss of pain & temperature
Localization of lesions
- you get a mixture of long tract signs and cranial nerve signs when there is a lesion in the brainstem
- the motor signs were the most useful in localizing lesions (this is coming from the pons, medulla)
What cranial nerves indicate particular lesions in the brainstem?
CN III midbrain), VI (caudal pons), and XII (GSE)—>MIDLINE
CN V (rostral pons), VII (lateral pontomedullary junction) and X (SVE)—> these are all branchiomotor
????
What are blood supply of the medulla, pons, and midbrain?
Motor cranial nerves/nuclei located in medial areas of infract
Long tracts located in medial areas of infract: CS, CB, Spinothalamic system for pain and temperature ???
What are the arteries Supplying Dorsolateral Areas of Medulla, Pons and Midbrain?
Motor cranial nerves/nuclei located in dorsolateral areas of infract
Long tracts located in dorsolateral areas of infract
????
What are the 3 major arteries that supply the spinal cord?
2 posterior spinal: dorsal column and dorsal horn; unilateral
anterior spinal: supplies the medulla ????
they come off of the at the level of the medulla
What is the major blood supply the brain?
vertebral artery that comes off of the subclavian
it ascends through the transverse foramen of the first 6 cervical vertebrae
when you reach C1 right and left vertebral arteries come together to form the basilar artery
What is the major source of clots in the brain?
comes after a heart attack
note: thrombi from the heart seldom form vertebral emboli because of the angle at which the artery is given off
???
Circle of Willis
you can bypass blockage of blood supply by going through the communicating arteries
middle cerebral is NOT part of the circle of willis
Anterior spinal
-supplies the innitialy the middle part of the medulla to the anterior part of the spinal cord
the vertebral artres gives off branches that anastomose to form the anterior spinal
Basilar artery
vertebral arteris anastomose at the pontomedullary junction t form the basilar artery
obstruction of cerebral arteries form a ‘wedged’ shaped infarct
?????
varies from individual to individual
What are the arteries supplying the medulla?
- beginning of medulla from spinal cord is the anterior spinal artery
- if we go higher to the beginning of the medulla, the anterior spinal is still supplying the closed medulla
a midline infarct ??????will affect pyramids and medial lemnisus
vertebral arteries give branches to the inferior olivary nucleus????
What is the most midline nucleus?
hypoglossal nucleus
When there is lesion between the open and closed medulla?
hypoglossal nerve parlaysis along with the pyramids and medial lemniscus
If there is a lesion at the pontomeduallry junction involving AICA, what are symptoms?
dorsal and ventral cochlear nuclei are affected
-diminished hearing (loss of hearing)
What is the medial medullary syndrome?
anterior spinal
medial branches of the verterbal artery
-paralysis of the tongue: fibers of CN XII as you go through the tongue
long tracts:
- Medial lemniscus: contralteral hemisensory
- corticospinal tract: contralateral hemiparesis loss
- MLF
paramedian
branches
spend more time on brain stem to identify these structures
roots of the abducens nerve facial nerve (more of a dorsolateral lesion)
???
????
CB did not label
medial lemniscus
What are the fibers affected in the medial pontine syndrome?
fibers of CN VI and VII if the lesion extends laterally
Long Tracts and Nuclei
- Medial Lemniscus
- Corticospinal Tract
- MLF (if lesion extends dorsally)
- Corticobulbar Tract (one going to the hypoglossal nucleus and the other to the nucleus ambiguus)
- Corticopontine Fibers and Pontine Nuclei
What is P1 and what territory does it supply?
Proximal Posterior Cerebral (P1)
End of Basilar
- red nucleus: major cerebellar structure( dendate and???)
- superior cerebellar peduncle
-medial lemniscus is too lateral to be in this area
???
P2 is after posterior communicating
???
