Cerebral Infarction (Clinical) Flashcards
what are the causes of ischaemic stroke?
Large artery atherosclerosis (e.g. Carotid) 35%
Cardioembolic (e.g. atrial fibrillation) 25%
Small artery occlusion (Lacune) 25%
Undetermined/Cryptogenic 10-15%
Rare causes <5%
Arterial dissection
Venous sinus thrombosis
what are th causes of a haemorrhage stroke?
Primary intracerebral hemorrhage 70%
Secondary hemorrhage 30%
Subarachnoid hemorrhage
Arteriovenous malformation
what are the causes of ischaemic stroke?
intracranial atherosclerosis carotid plaque with arteriogenic emboli aortic arch plaque cadiogenic emboli cryptogenic small artery disease flow reducing carotid stenosis carotid dissection
risk factors for ischaemic stroke
Modifiable smoking contraception obesity bad diet drugs diabetes low activity AF hypertension
Non-modifiable
Previous stroke
Age
Male
Family history
true or false:
anticoagulents reduce the risk of ischaemic stroke by 2/3rds
true
what are the frontal lobe fucntions?
High level cognitive functions ie. abstraction, concentration, reasoning
Memory
Control of voluntary eye movement
Motor control of speech (dominant hemisphere)
Motor cortex
Urinary continence
Emotion and personality
what are the parietal lobe functions?
Sensory cortex
Sensation (identify modalities of touch, pressure, position)
Awareness of parts of the body
Spatial orientation and visuospatial information (non dominant hemisphere)
Ability to perform learned motor tasks (dominant)
what are the temporal lobe functions?
Primary auditory receptive area
Comprehension of speech (dominant) – Wernicke’s
Visual, auditory and olfactory perception
Important role in learning, memory and emotional affect
what are the occipital lobe functions?
Primary visual cortex
Visual perception
Involuntary smooth eye movement
clinical presentations of stroke
Sudden onset loss of function: Motor (clumsy or weak limb) Sensory (loss of feeling) Speech: Dysarthria/Dysphasia Neglect / visuospatial problems Vision: loss in one eye (amaurosis fugax) or hemianopia Gaze palsy
Ataxia/ vertigo / incoordination / nystagmus
Stroke is a dynamic phenomenon where time is brain
what are the stroke classifications?
Total Anterior Circulation Stroke (TACS)
Partial Anterior Circulation Stroke (PACS)
Lacunar Stroke (LACS)
Posterior Circulation Stroke (POCS)
damage to right hemisphere causes
Left hemiplegia, homonymous hemianopia Neglect syndromes (agnosias) Visual agnosia Sensory agnosia Anosagnosia (denial of hemiplegia) Prosopagnosia (failure to recognise faces)
symptpms of TACS?
Complete hemiparesis/numbness Loss of vision on one side (hemianopia) Loss of awareness on one side (inattention) non-dominant or Dysphasia dominant
TACS is often due to blocked Carotid or Middle cerebral artery
why do PACS occur?
Branch of main artery In-between LACS and TACS 2 of 3 TACS criteria or One higher cortical deficit: Inattention Or dysphasia or Monoparesis
symptoms of LACS?
Weakness/numbness of:
Face + arm + leg
Or Face + arm
Or Arm + leg
May have dysarthria
Ataxic hemiparesis
No affect on higher function
Will not have dysphasia, inattention or hemianopia
what are the combination of symptoms of POCS?
Loss of balance/coordination Vertigo Double vision Dysarthria Visual loss (hemianopia)
what is the result of basilar artery occlusion?
Predominantly motor/oculomotor signs/symptoms
Bilateral but asymmetrical
Alteration in level of consciousness common
– may progress over 12-24hours
May present as reduced responsiveness
?cause requiring critical care
what do stroke mimics?
Seizures
Syncope (hypotension)
Sugar (hypo or hyper)
Sepsis (+previous stroke)
Severe migraine
Space occupying lesions
Si-chological (Functional)
what are migraine aura’s due to?
cortical spreading depression
what does migraine aura’s called?
Visual disturbances
scintillating scotomata
geometric (especially zigzag) patterns
positive symptoms (like a kaleidoscope, running water etc)
Can include sensory, motor or speech disturbance
Headache onset can be >1hour after the end of the aura or no headache
what is acute vestibular syndrome?
Can be very disabling
‘True vertigo’ vs unsteadiness vs dizziness
Nystagmus – unidirectional, increases in intensity when patient looks in direction of fast phase
Vomiting
Even an expert taking a careful history may remain uncertain
MRI can be helpful
what are the aims of acute ischaemic stroke therapies?
Restore blood supply.
Prevent extension of ischemic damage.
Protect vulnerable brain tissue.
who are the components of stroke units?
Clinical staff Stroke nurses Physiotherapists Speech and Language therapists Occupational therapists Dietician Psychologist Orthoptist
exclusionn 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
iinvestigations for stroke?
Routine blood tests (FBC, glucose, lipids, ESR…)
CT or MRI head scan (infarct vs. hemorrhage)
ECG + Holter (?AF, LVH)
Carotid doppler ultrasound (?stenosis)
Some patients
Echocardiogram (valves, ASD, VSD, PFO)
Cerebral angiogram/venogram (vasculitis?)
Hyper-coagulable blood screen
what are the secondary preventions?
Anti-hypertensives >25% Anti-platelets 25% Lipid lowering agents 25% Warfarin for AF 66% Carotid endarterectomy NNT of 3
