Cerebral Infarction (Clinical)

Question 1

what are the causes of ischaemic stroke?

Answer 1

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

Question 2

what are th causes of a haemorrhage stroke?

Answer 2

Primary intracerebral hemorrhage 70%
Secondary hemorrhage 30%
Subarachnoid hemorrhage
Arteriovenous malformation

Question 3

what are the causes of ischaemic stroke?

Answer 3

intracranial atherosclerosis
carotid plaque with arteriogenic emboli
aortic arch plaque
cadiogenic emboli
cryptogenic
small artery disease
flow reducing carotid stenosis
carotid dissection

Question 4

risk factors for ischaemic stroke

Answer 4

Modifiable
smoking
contraception
obesity
bad diet
drugs
diabetes
low activity
AF
hypertension

Non-modifiable

Previous stroke
Age
Male
Family history

Question 5

true or false:

anticoagulents reduce the risk of ischaemic stroke by 2/3rds

Answer 5

true

Question 6

what are the frontal lobe fucntions?

Answer 6

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

Question 7

what are the parietal lobe functions?

Answer 7

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)

Question 8

what are the temporal lobe functions?

Answer 8

Primary auditory receptive area

Comprehension of speech (dominant) – Wernicke’s

Visual, auditory and olfactory perception

Important role in learning, memory and emotional affect

Question 9

what are the occipital lobe functions?

Answer 9

Primary visual cortex

Visual perception

Involuntary smooth eye movement

Question 10

clinical presentations of stroke

Answer 10

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

Question 11

what are the stroke classifications?

Answer 11

Total Anterior Circulation Stroke (TACS)

Partial Anterior Circulation Stroke (PACS)

Lacunar Stroke (LACS)

Posterior Circulation Stroke (POCS)

Question 12

damage to right hemisphere causes

Answer 12

Left hemiplegia, homonymous hemianopia
Neglect syndromes (agnosias)
Visual agnosia
Sensory agnosia
Anosagnosia (denial of hemiplegia)
Prosopagnosia (failure to recognise faces)

Question 13

symptpms of TACS?

Answer 13

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

Question 14

why do PACS occur?

Answer 14

Branch of main artery
In-between LACS and TACS
2 of 3 TACS criteria
or	
One higher cortical deficit:
Inattention
Or dysphasia
or
Monoparesis

Question 15

symptoms of LACS?

Answer 15

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

Question 16

what are the combination of symptoms of POCS?

Answer 16

Loss of balance/coordination
Vertigo
Double vision
Dysarthria
Visual loss (hemianopia)

Question 17

what is the result of basilar artery occlusion?

Answer 17

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

Question 18

what do stroke mimics?

Answer 18

Seizures

Syncope (hypotension)

Sugar (hypo or hyper)

Sepsis (+previous stroke)

Severe migraine

Space occupying lesions

Si-chological (Functional)

Question 19

what are migraine aura’s due to?

Answer 19

cortical spreading depression

Question 20

what does migraine aura’s called?

Answer 20

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

Question 21

what is acute vestibular syndrome?

Answer 21

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

Question 22

what are the aims of acute ischaemic stroke therapies?

Answer 22

Restore blood supply.

Prevent extension of ischemic damage.

Protect vulnerable brain tissue.

Question 23

who are the components of stroke units?

Answer 23

Clinical staff
Stroke nurses
Physiotherapists
Speech and Language therapists
Occupational therapists
Dietician
Psychologist
Orthoptist

Question 24

exclusionn criteria for IV TPA?

Answer 24

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

Question 25

iinvestigations for stroke?

Answer 25

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

Question 26

what are the secondary preventions?

Answer 26

Anti-hypertensives		>25%
Anti-platelets			25%
Lipid lowering agents		25%
Warfarin for AF			66%
Carotid endarterectomy NNT of 3