Neuro 46: CVA

stroke

interruption of the blood flow to a part of the brain that usually produces a focal loss of function (except in subarachnoid hemorrhage)

1. sudden onset

2. focal involvement of CNS

3. lack of rapid resolution (> 24 hours)

4. vascular cause

what are the key features of a stroke (4)

occlusive

stroke do to closure of a BV; most caused by atherosclerosis and thrombosis

ischemia

insufficiency of blood supply; if temporary, symptoms and sign may clear with little or not pathological evidence of tissue damage

infarction

severe and prolonged ischemia where neurons die

hemorrhagic

stroke with bleeding from a vessels; most associated with hypertension and aneurysm

extraparenchymal

what type of hemorrhagic stroke causes subarachnoid hemorrhage

intraparenchymal

what type of hemorrhagic stroke may cause a blood clot or hematoma within the hemispheres, brain stem, or cerebellum

transient ischemic attack (TIA)

brief focal loss of brain function, with full recovery from neurologic deficits within 24 hours; 10-30% of people will have a stroke within 3 months

completed

stroke with neurologic deficits from vascular disorders that persist for longer than 1 day and are stable

progressive

ischemic stroke in which some people have deficits that increase intermittently over time

focal

direct infarcted ischemia

penumbra (peri-infarct)

indirect infarcted ischemia; impairs cerebral blood flow, control of CSF, and cerebral metabolism

1. location

2. size

3. structures involved

4. collateral blood flow

what are the factors that affect the severity of a stroke

superior division of MCA

what supplies broca’s area

superior division of MCA

what supplies frontal eye fields

superior division of MCA

what supplies the motor cortex

inferior division of MCA

what supplies the sensory cortex

inferior division of MCA

what supplies wernicke’s area

inferior division of MCA

what supplies the optic radiation

left

if language cognition is impaired, what side of the brain is the lesion likely on?

right

if the perception cognition is impaired, what side of the brain is the lesion likely on?

anterior choroidal artery

what artery affected if homonumous hemianopia?

leticulostriate

what artery involved?

superior division of MCA

what artery out?

left ACA

what artery damage?

lenticulostriate artery

which artery damaged:

• superior internal capsule out

• visual fields intact

• hemiparesis

• hemianesthesia

anterior choroidal artery

which artery damaged:

• inferior internal capsule out

• homonymous hemianopsia

• hemiparesis

• hemianesthesia

MCA

what does the lenticulostriate artery typically branch from?

ICA

what does the anterior choroidal artery typically branch from?

unilateral neglect

decreased body or environmental awareness of one side; fails to report or respond to stimuli presented on one side; person appears unaware of half of their body and/or of one side of space

anterior choroidal artery

what artery damaged:

parietal

what part of the brain if unilateral neglect?

primary motor area

where is the lesion?

• contralateral weakness or paresis

• contralateral spasticity

• brisk stretch reflexes

supplemental motor area (internal drive), ACA

where is the lesion and what artery?

• contralateral akinesia

• mutism

• loss of facial expression

• difficult with cooperative movements of both hands

• trouble performing self-limiting tasks

premotor area (external drive)

where is the lesion?

• apraxia

• movements are clumsy and slow

• rhythmic movements disrupted

• perseveration (repeating)

• difficulty performing sensory triggered tasks

posterior parietal cortex

where is the lesion?

• severe attentional disturbances of tactile or visual stimuli on one side of the body

• errors locating objects in space

• problems in performing complex postures

• unable to recognize complex objects placed in the hand without vision

• synthesize spatial coordinates of surrounding objects incorrectly

ACA

where is the lesion?

• leg area of primary motor and sensory cortex affected

• supplementary motor area (internal drive) affected

• motor planning affected

superior division of MCA

• contralateral weakness of face, hand, arm

• possible contralateral sensory deficit that affects the face, hand, and arm

• premotor area external drive; motor planning

  • apraxia (complex movement)

  • broca’s aphasia

apraxia

unable to perform complex tasks requiring sequencing of movement

inferior division of MCA

where is the lesion?

• possible contralateral sensory deficit that affects the face, hand and arm

• loss of stereognosis; extinction

• wernicke’s aphasia (lesion left side) - fluent aphasia

• neglect (lesion right side)

stem of MCA

where is the lesion?

• contralateral hemiplegia

• contralateral hemianesthesia

• contralateral homonymous hemianopia

• global aphasia (lesion left side)

• neflect (lesion right side)