Cerebral Infarction (Clinical) Flashcards
when does a transient ischemic attack resolve?
within 1-60 min- if longer patient will have lasting damage
what is ischaemia?
Is the failure of cerebral blood flow to a part of the brain
caused by an interruption of the blood supply to the brain
can be transient (as in TIA).
results in varying degrees of hypoxia (↓oxygen)
what does hypoxia do to the brain?
stresses the brain cell metabolism
especially important in the ischemic penumbra.
what occurs if the hypoxia is prolonged?
hypoxia→anoxia (no oxygen)
Anoxia →infarction (complete cell death, leading to necrosis)
This is a stroke
how can further damage occur outside of brain necrosis?
edema, depending on the size +location of the stroke
or secondary hemorrhage into the stroke.
what is the most important modifiable risk factor
for stroke?
Hypertension
what are the modifiable risk factors of stroke?
Hypertension Diabetes mellitus smoking ↑serum lipids ↑plasma level of low density lipoprotein (LDL) Alcohol Obesity
what are symptoms of ACA occlusion?
Contra-lateral:
paralysis of foot and leg
sensory loss over foot and leg
impairment of gait and stance
what are symptoms of MCA occlusion?
Contra-lateral
paralysis of face/arm/leg
sensory loss face/arm/leg
homonymous hemianopia
Gaze paralysis to the opposite side
Aphasia if stroke on dominant (left) side
Unilateral neglect and agnosia for half of external space if non-dominant stroke (usually right side).
what are right hemisphere stroke symptoms?
Left hemiplegia, homonymous hemianopia Neglect syndromes (agnosias): Visual agnosia Sensory agnosia Anosagnosia (denial of hemiplegia) Prosopagnosia (failure to recognise faces)
what are Lacunar stroke syndromes?
Devoid of ‘cortical’ signs E.g. no dysphasia, neglect, hemianopia Pure motor stroke Pure sensory stroke Dysarthria - clumsy hand syndrome Ataxic hemiparesis
what are posterior circulation stroke symptoms?
Coma, vertigo, nausea, vomiting, cranial nerve palsies, ataxia Hemiparesis, hemisensory loss Crossed sensori-motor deficits Visual field deficits
what is the treatment for stroke?
Aspirin Stroke Unit Thrombolysis Thrombectomy Tissue Plasminogen Activator (TPA)
what is the criteria for TPA use?
< 4.5 hours from symptom onset
Disabling neurological deficit
Symptoms present > 60 minutes
Consent obtained
what is the exclusion criteria for IV TPA?
Anything that increases the possibility of hemorrhage: blood on CT scan recent surgery recent episodes of bleeding coagulation problems BP >185 systolic or >110 diastolic Glucose <2.8 or > 22mmol/L
