Intro to Stroke Flashcards
Ischemia vs infarction
Ischemia: inadequate blood supply to a tissue or organ
Infarction: area of dead tissue resulting from impaired blood supply
TIA definition
Transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia
Without acute infarction
Stroke definition
Neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia
With acute infarction
Ischemic stroke
85%
Stroke resulting from occlusion of a blood vessel
Hemorrhagic stroke
15%
Stroke resulting from rupture of a blood vessel
2 types: intracerebral hemorrhage and subarachnoid hemorrhage
Are epidural and subdural hematomas considered hemorrhagic strokes?
No
What arteries supply the cortex for the
- Legs
- Arms, hand and face
- ACA
2. MCA
Left middle cerebral artery (MCA) stroke signs
Right hemiplegia (damage to precentral gyrus)
Right hemianesthesia (damage to postcentral gyrus)
Right homonymous hemianopsia (optic radiations)
Global aphasia (Wernickes and Brocas areas)
Left gaze deviation/preference (frontal eye fields)
Homonymous hemianopsia
Where a person only sees one side of vision in each eye
If you
1. stimulate
2. inhibit
frontal eye fields, which way will the eyes go?
- Contralateral eye movement (ex: seizure)
2. Ipsilateral eye movement (ex: stroke)
Right middle cerebral artery (MCA) stroke symptoms
Left hemiplegia Left hemianesthesia Left homonymous hemianopsia Left hemineglect (no aphasia, because language is on left) Right gaze deviation/preference
Left anterior cerebral artery (ACA) stroke symptoms
Right leg > arm weakness
Right leg > arm sensory loss
Frontal lobe behavioural abnormalities
Left posterior cerebral artery (PCA) stroke signs
Right homonymous hemianopsia
If there is a proximal PCA occlusion, can also see right hemisensory loss and right hemiparesis
“Top of the Basilar” stroke syndrome
Small perforator arteries supplying the thalamus and midbrain get blocked
Decreased level of consciousness (sometimes the only finding)
Varying degrees of: dysarthria, visual field deficit, eye movement abnormalities, weakness, ataxia, numbness)
“Locked in” syndrome
Mid basilar occlusion (problem with the pons)
Bilateral horizontal gaze palsy (can only move eyes up and down)
Bifacial weakness (can only blink)
Anarthria (cannot speak)
Quadriplegia from damaged corticospinal tracts (cannot move)
Lateral medullary syndrome
Vertebral artery or PICA occlusion
Vertigo, nausea, vomiting, ipsilateral Horner’s syndrome (ptosis, miosis, anhydrosis), hoarseness, dysarthria, dysphagia, ipsilateral facial numbness, contralateral body numbness, ipsilateral ataxia, hiccups
NO WEAKNESS (so often missed)
4 symptoms of a cerebellar stroke
Ataxia (ipsilateral)
Nystagmus (beat towards lesion)
Dysarthria
Vertigo, nausea, vomiting
3 main stroke mechanisms
Large artery atherosclerosis
Small vessel lacunar stroke
Cardioembolism
Large vessel atherosclerosis disease
Can affect extracranial and intracranial vessels
Common sites: aortic arch, carotid bifurcations*, vertebral artery origins, etc
Amaurosis fugax
Painless transient vision loss
Monocular or binocular
Where is the lesion if the amaurosis fugax is
- monocular
- binocular
- Anterior to optic chiasm (eye or optic nerve) (ischemia from ipsilateral carotid artery)
- Optic chiasm or posterior (optic tracts/radiations or visual cortex)
2 main causes of monocular transient vision loss
Carotid artery stenosis
Giant cell arteritis
Small arteries in the brain can be damaged by what 4 diseases/activities
Hypertension
Hyperlipidemia
Diabetes
Smoking
Small vessel disease leads to strokes in what 5 areas
Corona radiata Basal ganglia Internal capsule Thalamus Pons
