Blood supply Flashcards
What is affected when the Paramedian Artery of the Basilar Artery is lesioned
Abducens nucleus - abducts the eye
Medial lemiscus
Corticospinal/corticobulbar fibers
What is affected when the Short Cercumferential of the Basilar Artery is lesioned
Spinothalalmic
Facial Nucleus
What is affected when the Short Cercumferential of the Basilar Artery is lesioned
Spinothalalmic
Facial Nucleus
What is affected when the Long Cercumferential of the Basilar Artery is lesioned
spinal V tract and nu.
-hoarseness, dysphagia, and left soft palate weakness
Patient with lateral medullary damage.
Uvula deviates to contralateral to damaged slide.
Deviates to the Right.
Damage to the CN XII
Coud be an issue with the PICA (artery)
Spinal Cord Ischemia
Anterior Spinal Artery - small & tenuous; occlusion produces bilateral damage (below lesion effects) to:
- Corticospinal tracts – paraplegia below lesion
- Spinothalamic tracts – thermoanesthesia & analgesia
- Descending autonomic tracts – loss of bladder & bowel control
- Damage to anterior gray horns near enlargements – weakness of limb muscles
Middle Cerebral Artery does what
- All language areas (left MCA in most people)
- Most of primary motor & premotor cortex, frontal eye field, & primary somatosensory cortex (exceptions – lower limb & perineum)
- Auditory cortex
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Lenticulostriate arteries are a branch of what?
Do what?
Middle Cerebral Artery
basal ganglia & internal capsule (all divisions)
Anterior Cerebral Artery does what?
- Motor & Somatosensory cortex (lower limb & perineum only)
- Corpus callosum (except for splenium)
- Olfactory bulb & tract
- head of caudate (ventral portion) & adjacent putamen
- Recurrent Artery of Heubner – caudate (anteromedial portion) & internal capsule (anterior limb & genu)
Recurrent Artery of Heubner –
caudate (anteromedial portion) & internal capsule (anterior limb & genu)
Posterior Cerebral Artery
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- Hippocampus
- Parahippocampal gyrus
- Calcarine branch – all primary & some association cortex for vision
- choroid plexus (lateral & 3rd ventricle), thalamus (posterior part), fornix, tectum
- Anterior Choroidal Artery
- Hippocampus, uncus & amygdala
- Choroid plexus (temporal horn of lateral ventricle)
- Globus pallidus, putamen, part of thalamus
- Internal capsule (posterior limb)
Subarachnoid hemorrhage - non-tramatic
- meningeal irritation from blood in the CSF; due to rupture of an aneurysm in the subarachnoid space
- “worst headache of my life”
- Saccular aneurysms:
- Balloon-like outpouchings; neck connects parent vessel to fragile dome that can rupture
- arise from arterial branch points
- 85% in anterior circulation
- risk factors of aneurismal rupture: hypertension, cigarette smoking, alcohol consumption, sudden elevation in blood pressure
- affects adjacent structures e.g., pcomm arising from ICA – can cause painful 3rd nerve palsy
- Traumatic Subarachnoid Hemorrhage:
- more common than spontaneous ones
- bleeding into CSF from vessels due to contusions [coup (i.e., side of impact) and contrecoup] and other traumatic injuries
- also associated with severe headache
Intracerebral Hemorrhage
- Within the brain parenchyma or spinal cord
- Traumatic – example: contusions of the cerebral hemispheres “ where cortical gyri abut ridges of bony skull “ thus, most common at temporal & frontal poles
- Non-traumatic – some causes include hypertension, brain tumors, secondary hemorrhage after ischemic infarction
Epidural Hematoma:
- between dura & the skull
- rupture of middle meningeal artery due to fracture of the temporal bone by head trauma
Subdural Hematoma:
- Between dura & arachnoid
- rupture of bridging veins: vulnerable to shear injury as they cross from arachnoid into dura
Ischemic Stroke -* *Embolic infarct
- a piece of material formed in one place (such as a blood clot) and travels through bloodstream
- lodges suddenly into a blood vessel supplying the brain and occludes it
- large-vessel infarcts are most often caused by emboli
- Examples, aside from thrombotic material, include air emboli (deep sea divers) and fat or cholesterol emboli.
- prevention of future strokes – important to determine the source of the embolus, such as the heart “
Cardioembolic infarcts:
atrial fibrillation
myocardial infarction
valvular disease
Thrombotic infarct
- Blood clot formed locally, usually at the site of an underlying atherosclerotic plaque.
- Causes occlusion of the vessel
Acute stroke treatment
Once a CT rules out hemorrhage, many patients get treated with thrombolytic agents, such as tissue plasminogen activator (t-PA). If given within _3 hours_ of stroke onset, chances improve for a good functional recovery.
Lacunar Infarcts:
- Refers to small vessel infarcts
- Often caused by chronic hypertension
- Lacunar syndromes include thalamic lacunes (can cause contralateral somatosensory deficits) and basal ganglia lacunes (can cause movement disorders such as hemibalismus – unilateral flinging movements of the extremities contralateral to the lesion)
Lacunar syndromes
- thalamic lacunes (can cause contralateral somatosensory deficits)
- basal ganglia lacunes (can cause movement disorders such as hemibalismus – unilateral flinging movements of the extremities contralateral to the lesion)
Transient Ischemic Attack (TIA):
*
- neurologic deficit
- caused by temporary brain ischemia
- lasts < 24 hrs (typically about 10 min)
- important warning sign for a larger ischemic injury
- possible mechanism – embolus temporarily occludes vessel but then dissolves
Watershed Infarcts:
- regions between adjacent cerebral arteries – watershed zones
- these zones are most susceptible to ischemia & infarction when blood supply to two adjacent cerebral arteries is compromised
- ACA-MCA watershed infarcts can occur due to a sudden occlusion of the internal carotid
- Uncal herniation – clinical triad
- “blown pupil”: compression of CNIII
- hemiplegia: compression of cerebral peduncles
- coma: distortion of midbrain reticular formation
What is the artery supply of the Midbrain
SCA and Proximal PCA
Paramedian Branches at the Top of the Basilar Artery
What is the Arterial supply of the Rostral Pons
Superior Cerebellar Artery
Basilar Artery
-Paramedian Branches
Circomfrential branches
Blood supply of the Caudal Pons
AICA
Basilar Artery
-Lateral Pontine arteries
Blood supply of the rostral Medulla
Vertebral Artery
-Paramedian Branches
PICA
