7.2.1 CNS Vasculature Flashcards
What is medial pontine syndrome caused by?
Blockage of paramedian branches of the basilar artery
What occurs in opthalmic artery stroke?
- Ophthalmic artery is a branch off of the ICA
- Supplies: retina, optic nerve, glove, orbit, frontal scalp, and frontal/ethmoid sinuses
- Deficits due to occlusion:
- -Ipsi blindness
- -Painless
- -Amaurosis Fugax: transient blindness as clot moves and restores blood flow
What are the arrows pointing to and what symptoms could appear if damage were to occur to these areas?
Draw a diagram depicting the blood flow distribution in the pons.
What are the common syndromes associated with blockage of the posterior cerebral artery?
Draw a diagram depicting the blood flow distribution in the midbrain.
What areas of the brain does posterior circulation supply?
- Medulla
- Pons
- Midbrain
- Thalamus
- Occipital Lobe
- Ventromedial Temporal Lobe
What happens in an internal carotid artery stroke?
What are the arrows pointing to and what symptoms could appear if damage were to occur to these areas?
What lateral pontine syndrome caused by?
Blockage of the long circumferential branches of the basilar artery and AICA
What are the cortical syndromes associated with PCA occlusion?
- P2: cortical and temporal lobe signs
- Contra homonymous hemianopia with macular sparing
- Acute disturbance in memory if lesion reaches hippocampus
What is medial medullary syndrome?
Alternating hypoglossal hemiplegia
Inadequate blood flow to area supplied by Anterior spinal artery
What will be the symptoms of a superior division stroke of the MCA?
- Occurs after the bifurcation of the M1 segment of MCA
- Superior division supplies lateral surface of frontal and parietal lobes above the lateral sulcus
- Deficits resulting from stroke:
- Postcentral Gyrus: contra hemisensory deficit with sparing of leg and foot
- Precenral Gyrus: contra hemiparesis with sparing of leg and foot
- Broca’s Area: expressive aphasia if stroke in dominant (left) hemisphere
- Frontal Eye Fields: ipsi deviation of head/eyes
-No impairment of alertness
What are the lenticulostriate arteries and what is the importance of them?
What occurs in a bilateral vs unilateral ACA occlusion?
What will the symptoms be of an inferior division stroke of the MCA?
- Occurs after the bifurcation of the M1 segment of MCA
- Inferior division supplies: lateral surface of the temporal lobe below the lateral sulcus
- Deficits resulting from stroke:
- -Wernicke’s: receptive aphasia, if stroke in dominant (left) hemisphere
- -Visual Radiations/ Primary Visual Cortex:
- -Superior quadrantanopsia or homonymous hemianopsia depending on stroke size
- -Left visual neglect, when in NON-dominant (right) hemisphere
-Agitation and confused state may result with stroke to NON-dominant hemisphere
What are the arrows pointing to and what symptoms could appear if damage were to occur to these areas?
What is a P1 syndrome?
-Infarction typically in ipsi subthalamus and medial thalamus and in ipsi cerebral peduncle/midbrain
- -Can cause Weber’s Syndrome (Medial Midbrain)
- -Ipsi oculomotor ophthalmoplegia
- -Contra hemiplegia
-Can also cause Thalamic Syndrome (Dejerine-Roussy) if the Thalamogeniculate A is occluded
- -Contra hemisensory loss; burning pain in affected area
- -Hemiparesis, hemiballismus, choreoathetosis
- -Intention tremor
- -Ataxia
What are the arrows pointing to and what symptoms could appear if damage were to occur to these areas?
Facial Droop means AICA’s pooped
What are the arrows pointing to and what symptoms could appear if damage were to occur to these areas?
What areas of the brain are included in anterior circulation of blood?
- Remaining cerebral cortex
- Basal Ganglia
- Hypothalamus
What is medial midbrain syndrome caused by?
Blockage of the paramedian branches of the basilar bifurcation and P1 segement
Describe the branching of the MCA
- MCA is derived from the Internal Carotid Artery of the Anterior Circulation
- Divides into three major portions:
- -Segments M1, M2, M3, M4: Supplying cortical regions
- -Lenticulostriate Branches: Supplying subcortical regions
-Branching Pattern: ICA ⇒ M1
- -M1 bifurcates into a superior and inferior division
- -Both divisions have same pattern:
- -M2 ⇒ M3 ⇒ M4
Infarct at the M1/M2 junction will result in?
Combination of superior and inferior division deficits
What is Lateral Medullary syndrome caused by?
Blockage of the PICA which perfuses the lateral medulla
Draw a diagram depicting the blood flow distribution in the medulla.
