Lecture 4: CVA Flashcards
Types of Strokes
1) Hemorrhagic: 17%, occur as a result of bleeding in the brain due to an injury to head or ruptured aneurysm of a vessel (produce more fatalities)
2) Ischemic stroke: 83%, occur because of clot formation in blood vessels
Types of Hemorrhagic Strokes
1) Intracerebral Hemorrhage (59%)- occurs when defective artery in brain ruptures and surrounding area of brain fills with blood
2) Subarachnoid Hemorrhage (41%)- occurs when b. vessel on surface of brain ruptures and bleeds into subarachnoid space btwn skull
Types of Ischemic Strokes:
1) Cerebral Embolism (20%): result of clot (embolus) that forms in another part of body and is carried to brain, becoming lodged in artery that supplies blood to brain; flow is blocked
2) Artherosclerotic Cerebrovascular Dz (20%): stroke occurs due to severe arterial stenosis or occlusion due to severe arteriosclerosis and coexisting thrombosus
3) Lacunar Infacrts (25%): results from microatheroma, lipohyalinosis and other occlusive dz.’s of the small penetrating arteries in the brain (usually basal ganglia, pons, cerebellum)
4) Cryptogenic (30%): unknown cause
Lacunar Strokes
- small infarctions occur secondary to small vessel damage
- usually resulting from HTN or DM
Most common areas affected by lacunar strokes
Basal ganglia and internal capsule!
-other areas affected: pons, cerebellum, thalamus
Clinical Features of Lacunar strokes
1) Pure Motor Hemiplegia
2) Pure Sensory Strokes
3) Ataxic Hemiparesis
4) Secondary Motor Syndrome
5) Dysarthria CLumsy hand syndrome
Pure Motor Hemiparesis
- contralateral weakness involving face-arm-leg
- limbs equally affected
- lesions occur in pons or internal capsule
Pure Sensory Stroke
parathesias in face-arm-leg
-lesions occur in thalamus
Ataxic Hemiparesis
incoordination accompanied by weakness of some limbs
-lesions usually in pons
Secondary Motor Syndrome
causes weakness and sensory deficits of face-arm-legs
-lesions in posterior limb of internal capsule
Dysarthria Clumsy Hand syndrome
slurred speech with clumsy contralateral hand
-lesions in pontine or brainstem lacunes
MCA Infarction
contralateral hemiparesis, aphasia, homonymous hemianopsia
MCA infacrtion: Dominant side
Aphasia: Broca’s, Wernicke’s or global
Gaze preference: toward side of lesion
MCA stroke: non dominant side
Neglect, spatial disorientation: do not recognize anything on dominant side (so contralateral neglect)
also have agnosia-anosognosia
Anterior cerebral artery stroke
contralateral weakness: lower extremities and face
posterior cerebral artery stroke
homonymous hemianopsia contralateral to side involved: so R sided lesion cannot see L side
Basilar Artery Stroke
may present with: quadriplegia, coma, altered consciousness, pupillary abnormalities, ocular palsy
Basilar Artery Stroke: depend on CN involved
but remember: have ipsilateral deficit with CN nerves
Example: CN VII involvement: ipsilateral facial weakness: upper and lower
With Basilar Artery stroke: Locked in syndrome
can only move eyes vertically
Vertebral Artery Stroke
-sx’s similar to basilar artery: contralateral hemiplagia and sensory deficit and ipsilateral CN palsy
Hemorrhagic Stroke: Etiology
- **HTN
- amyloid angiopathy
- AV malformation
- cavernous angioma
- intracranial aneurysm
- dural venous sinus thrombosis
- coagulopathy
- hemorrhagic conversion of infarction
- neoplasm or infxn
Intracerebral Hemorrhage
most common causes HTN
Other causes: bleeding disorders, anticoag therapy, liver dz, High EtOh or primary/secondary brain tumors
Intracerebral hemorrhage sx’s
LOC, N/V, evoloving hemiplaegia or hemiparesis
Thalamic hemorrhage
loss of upward gaze, downward or skew deviation, pupillary inequalities
