Neural anatomy 2 Flashcards
what artery connects the two anterior cerebral arteries
anterior communicating artery
where do the lenticulostriate arteries branch off from
MCA
what does the anterior choroidal artery branch off of
MCA
what do the vertebral arteries branch off of
the subclavian arteries
name the arteries branching off of the vertebral, then basilar artery starting from most inferior to most superior
PICA, AICA, SCA
what are watershed zones and what happens when they’re poorly perfused
areas the lie between the major cerebral arteries; severe hypotension causes upper leg/ upper arm weakness, and defects in higher-order visual processing
cerebral blood flow is modulated by ________?
PCO2
what is the point of therapeutic hyperventilation
to decrease PCO2 in order to decrease intracranial pressure in cases of acute cerebral edema via decreased cerebral perfusion by vasoconstriction
what are the areas of lesion for an MCA stroke
motor cortex, somatosensory cortex, temporal lobe
what are the deficits seen in an MCA stroke and what areas of cortex do they correspond with
contralateral paralysis of the face and upper limb-motor cortex
contralateral loss of sensation-sensory cortex
receptive aphasia (if in dominant side, usually left)
hemineglect (if in nondominant side, usually right)
what areas are affected by an ACA
motor cortex and sensory cortex
what are the deficits seen in an ACA stroke and what areas of cortex do they correspond with
contralateral paralysis of lower limb-motor cortex
contralateral loss of sensation in lower limb-sensory cortex
what are the areas affected by a lenticulostriate stroke
striatum and internal capsule
what are the deficits seen in a lenticulostriate stroke
contralateral hemiparesis and hemiplegia
what condition is commonly associated with infarction of the lenticulostriate arteries
lacunar infarcts secondary to unmanaged hypertension
what are the areas lesioned by an ASA infarct
lateral corticospinal tract, medial lemniscus, hypoglossal nerve
what are the deficits seen with an ASA infarct
contralateral hemiparesis (upper and lower limbs), contralateral decreased proprioception, ipsilateral hypoglossal dysfunction (tongue deviates toward lesion)
what common syndrome is seen with ASA infarcts
medial medullary syndrome
what areas are lesioned by a PICA infarct
lateral medulla= vestibular nuclei, lateral spinothalamic tract, spinal trigeminal nucleus, nucleus ambiguus, sympathetic fibers
inferior cerebellar peduncle
what symptoms are seen with a PICA infarct
vomiting, vertigo, nystagmus; decreased pain and temperature sensation from ipsilateral face and contralateral body; dysphagia, hoarseness, decreased gag reflex; ipsilateral Horner syndrome; ataxia, dysmetria
what is the name of the syndrome seen with a PICA infarct
Wallenberg syndrome (don't PICA hoarse that can't eat (dysphagia))
what areas are lesioned with an AICA infarct
lateral pons- vestibular nucleus, facial nucleus, spinal trigeminal nucleus, cochlear nucleus, sympathetic fibers
middle and inferior cerebellar peduncles
what are the symptoms of an AICA infarct and what’s the syndrome called?
Lateral pontine syndrome- vomiting, vertigo, nystagmus, facial paralysis, decreased lacrimatio and salivation, decreased taste from anterior 2/3 of tongue, decreased corneal reflex, decreased facial pain and temp. sensation, decreased ipsilateral hearing, ipsilateral Horner syndrome, ataxia, dysmetria
what infarction should you automatically think of when there is a facial droop
AICA (lateral pontine syndrome)
what areas are lesioned by a PCA infarct
occipital cortex, visual cortex
what are the deficits seen with a PCA
contralateral hemianopia with macular sparing
what gets lesioned in a basilar artery infarct
pons, medulla, lower midbrain, corticospinal and corticobulbar tracts, ocular cranial nerve nuclei, PPRF (paramedian pontine reticular formation)
what clinical presentation do you see with infarction of the basilar artery
locked in syndrome: preserved consciousness and blinking, quadriplegia, loss of voluntary facial, mouth and tongue movements
what are the symptoms seen with infarction of the anterior communicating artery
visual field defects
what is the most common kind of lesion in the anterior communicating artery
aneurysm; berry aneurysms can impinge cranial nerves and can less commonly lead to stroke
where do berry aneurysms occur
in the bifurcations of the arteries in the circle of Willis
what kind of hemorrhage is seen when berry aneurysms rupture
subarachnoid hemorrhage
what visual defect is common with berry aneurysms
bitemporal hemianopia via compression of the optic chiasm
name three conditions that are associated with berry aneurysms
ADPKD, Ehlers-Danlos, Marfan
what are some risk factors for berry aneurysm
advanced age, hypertension, smoking, race (increased risk in blacks)
what kind of lesion commonly occurs in the posterior communicating
saccular aneurysm
what symptoms are seen when there is a lesion of the PComm
CN III palsy: eye is “down and out”, ptosis, and pupil dilation
do strokes or aneurysms more commonly cause PComm lesions
aneurysms
what kind of aneurysm is a Charcot-Bouchard microaneurysm
aneurysm of small vessels (e.g. basal ganglia or thalamus), associated with chronic hypertension
what is central post-stroke pain syndrome
neuropathic pain due to thalamic lesions; initial numbness and tingling followed in weeks to months by allodynia (unprovoked pain) and dysaesthesia (discomfort)
what percentage of stroke patients experience central post-stroke pain syndrome
10%
