Flashcards in Cerebral Infarction (Clinical) Deck (17):
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
what are the modifiable risk factors of stroke?
↑plasma level of low density lipoprotein (LDL)
what are symptoms of ACA occlusion?
paralysis of foot and leg
sensory loss over foot and leg
impairment of gait and stance
what are symptoms of MCA occlusion?
paralysis of face/arm/leg
sensory loss face/arm/leg
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):
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
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?
Tissue Plasminogen Activator (TPA)
what is the criteria for TPA use?
< 4.5 hours from symptom onset
Disabling neurological deficit
Symptoms present > 60 minutes
what is the exclusion criteria for IV TPA?
Anything that increases the possibility of hemorrhage:
blood on CT scan
recent episodes of bleeding
BP >185 systolic or >110 diastolic
Glucose <2.8 or > 22mmol/L
what are the investigations for stroke?
Routine blood tests
CT or MRI head scan
Carotid doppler ultrasound
Hyper-coagulable blood screen