Stroke Flashcards
Stroke
- cerebrovascular accident (CVA)
- “brain attack”
Types of stroke:
- Ischemic stroke (IS) 75 - 85%
- Intracerebral hemorrhage (ICH) 10 - 20%
- Subarachnoidal hemorrhage (SAH) ok. 5%
Stroke def:
is a syndrome caused by a disruption in the flow of blood to part of the brain due to either occlusion of a blood vessel (ischemic stroke) or rupture of a blood vessel (hemorrhagic stroke).
The interruption in blood flow deprives the brain of nutrients and oxygen, resulting in injury to cells in the affected vascular territory of the brain.
Ischemic strokes are more common than hemorrhagic strokes.
Stroke - death:
The third most common cause of death
Cerebral blood flow (CBF) - NORMAL:
ca. 55ml/100g/min
Cerebral blood flow (CBF) - POTENTIALLY REVERSIBLE:
30ml/100g/min
Cerebral blood flow (CBF) - POTENTIALLY IRREVERSIBLE ISCHEMIA:
<10ml/100g/min
Transient ischemic attack, TIA:
<24 hours
Reversible ischemic neurological deficit, RIND:
<21 days
Minor and major strokes:
- Minor stroke (non-disabling)
- Major stroke (disabling)
Factors associate with an increase risk of a stroke:
- Age (increased with age)
- Gender (males>females)
- Race (Blacks>Asians and Hispanics>Whites)
- Geographic region (Eastern Europe>Western Europe; Asia > Europe or North America)
- Family history (stroke or heart disease
Potentially modifiable risk factors for stroke:
- Hypertension
- Diabetes mellitus
- Hyper lipidemia
- Smoking
- Atrial fibrillation
- Hyperhomocysteinemia
- Physical activity
Other potential risk factors for stroke:
- Migraine
- Oral contraceptives
- Obesity
- Pregnancy
- Alcohol abuse
- Drug abuse
- Sleep disorders (sleep apnea)
Types of IS:
- atherosclerotic
- cardioembolic
- lacunar
- others
- undetermined
Lacunes:
Lacunes are caused by occlusion of a single that arises directly from the constituents of the Circle of Willis, cerebellar arteries, and basilar artery.
Lacunes location:
The corresponding lesions occur in the deep nuclei of the brain (37% putamen, 14% thalamus, and 10% caudate) as well as the pons (16%) or the posterior limb of the internal capsule (10%).
They less commonly occur in the deep cerebral white matter, the anterior limb of the internal capsule, and the cerebellum.
Lacunar infarcts:
- „deep structures” of hemispheres
- brain stem
- cerebellum
Other causes of lacunar infarcts - Vasculopathies:
- Noninflammatory (dissection, vasospasm, others)
- Inflammatory (PAN, SLE, vasculitis, others)
- Infectious (syphilis, Herpes Zoster, AIDS, others)
Other causes of lacunar infarcts - Hematologic and coagulation disorders:
- Polycythemia, thrombocytosis, trombocytopenia
- Antithrombin III deficiency
- Protein C or S deficiency
- Deficiency of factors V, VII, XII, XII
- Antiphospholipid/anticardiolipin antibodies
- Malignancy
- Pregnancy
- Oral contraceptives
Undetermined IS:
Coexistence of few possible factors (i.e.FA and carotid stenosis)
Symptoms of stroke:
- Symptoms depend on localization and size of lesion
- Less on etiology/cause of stroke
- Focal symptoms
- Global symptoms
Symptoms of stroke - Time course and evolution:
- Sudden or rapid onset of symptoms
- in the morning, in daytime
- on sleep, exercise
- Reach maximal intensity within 24 hours
- Gradual or stepwise worsening can occur
Symptoms of stroke - Focal neurological symptoms:
- Cognitive impairments (aphasia, neglect, apraxia)
- Weakness or incoordination of limbs
- Facial weakness
- Numbness of limbs and/or face
- Cranial nerve palsies
Symptoms of stroke - Global symptoms and signs:
- Headache
- Nausea and vomiting
- Altered mentalstatus
- syncope
- seizure
- coma
- Hypertension and abnormal vital signs
- Nuchal rigidity
Symptoms of TIA/stroke:
Carotid circulation
- Ipsilateral monocular blindness
- Contralateral weakness, numbness (hand, arm, face, leg)
- Aphasia
Left hemisphere (ie, dominant)
- Right hemiparesis, variable involvement of face and upper and lower extremity
- Right-sided sensory loss, in a similar pattern to the motor deficit; usually involves all modalities, decreased stereognosis, graphesthesia
- Right homonymous hemianopia
- Aphasia, fluent and nonfluent
- Alexia
- Agraphia
- Acalculia
- Apraxia
Right hemisphere (ie, nondominant)
- Left hemiparesis (same pattern as on right)
- Left-sided sensory loss (similar pattern as the motor deficit)
- Left homonymous hemianopia (same pattern as on right)
- Neglect of the left side of environment
- Anosognosia
- Asomatognosia
- Loss of prosody of speech
- Flat affect
Anterior choroidal artery territory (ACA territory)
- Hemiparesis
- Hemianesthesia
- Homonymous hemianopia
Lacunar syndromes - Pure motor hemiparesis:
- Contralateral, usually affecting the face and upper and lower extremities equally
- Also associated with dysarthria
- No sensory or visual loss or cognitive impairment
Lacunar syndromes - Pure sensory stroke:
- Contralateral loss of all sensory modalities, equally affecting the face and upper and lower extremities
- No motor signs, dysarthria, visual loss, or cognitive impairment
Lacunar syndromes - Dysarthria-clumsy hand syndrome:
Dysarthria, dysphagia, contralateral tongue and facial weakness and paresis, and clumsiness of the contralateral arm and hand
Lacunar syndromes - Homolateral ataxia and crural paresis:
Paresis of the contralateral leg and side of the face, prominent ataxia of the contralateral leg and arm
- also called “ataxic hemiparesis,” meaning ataxia and weakness on the same side
Lacunar syndromes - Isolated motor/sensory stroke:
- Paralysis and sensory loss of the contralateral leg, arm, and face
- No visual loss or cognitive impairment
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