Cerebral infarction (CLINICAL) Flashcards by J Murray

at what age do the majority of strokes occur

~75% in >65 yr olds

How well did you know this?

Not at all

Perfectly

define stroke

the sudden onset of focal or global neurological symptoms caused by ischemia or hemorrhage and lasting more than 24 hours

How well did you know this?

Not at all

Perfectly

define transient ischaemic attack (TIA)

the term used if the symptoms resolve within 24 hours

most resolve within 1-60 mins

How well did you know this?

Not at all

Perfectly

what is more common - ischaemic or haemorrhagic stroke

ischaemic - 85%

How well did you know this?

Not at all

Perfectly

what are the most common 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

How well did you know this?

Not at all

Perfectly

what are the causes of haemorrhagic stroke

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

How well did you know this?

Not at all

Perfectly

what are the investigations for stroke

blood tests - FBC, glucose, lipids, ESR

CT or MRI head - infarct vs haemorrhage

ECG - ?AF, LVH

Echocardiogram - valves, ASD, VSD, PFO

carotid doppler US - ?stenosis

Cerebral angiogram/venogram - ?vasculitis

hyper-coagulable blood scan

How well did you know this?

Not at all

Perfectly

what can conditions can present like stroke but are not stroke

Post-ictal states (e.g. Todd’s paralysis)

Hypoglycemia

Intracranial masses

Vestibular disease

Bell’s palsy

Functional hemiparesis

Migraine

Demented patients with UTIs

How well did you know this?

Not at all

Perfectly

what is the incidence and impact of stroke

2nd, 3rd cause of death in developed countries

number 1 cause of disability in adults

150,000 new stroked/year in the UK

How well did you know this?

Not at all

Perfectly

what is the public awareness campaign for stroke

act FAST

F- facial weakness
A - arm weakness
S - speech problems
T - time to call 999

How well did you know this?

Not at all

Perfectly

what are the 4 basic steps in the pathophysiology of stroke

ischaemia develops
results in hypoxia
leads to anoxia
leads to infarction

How well did you know this?

Not at all

Perfectly

explain the ischaemic stage of stroke pathophysiology

ischaemia:

failure of the 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 (decreased oxygen)

How well did you know this?

Not at all

Perfectly

explain the hypoxic stage of stroke pathophysiology

hypoxia:

stresses the brain cell metabolism (especially important in the ischameic penumbra)
if prolonged hypoxia - leads to anoxia (no oxygen)

How well did you know this?

Not at all

Perfectly

explain the anoxic and infarction stages of stroke pathophysiology

anoxia:
- leas to infarction

infarction:

complete cell death leading to necrosis
this is a stroke

How well did you know this?

Not at all

Perfectly

what can further damage result from in stroke

edema - depending on size and location of stroke

secondary haemorrhage into the stroke

How well did you know this?

Not at all

Perfectly

what is the penumbra

the area surrounding an ischemic event such as thrombotic or embolic stroke - oxygen supply to this area is also disrupted - leads to hypoxia in the surrounding area

How well did you know this?

Not at all

Perfectly

how can total arterial occlusion develop in ischaemic stroke

disruption/injury to a plaque surface
platelet adhesion/aggregation and fibrin formation on plaque
thrombus formation
leads to total arterial occlusion due to thrombus

if parts of the thrombus break off and block further areas = embolus

How well did you know this?

Not at all

Perfectly

what are the two groups of risk factors for stoke and give examples of each

modifiable

hypertension
smoking
cholesterol
diet
high BMI
alcohol

non-modifiable

previous stroke
age
male
family history

diabetes

How well did you know this?

Not at all

Perfectly

what is the most important modifiable risk factor for stroke and why

HYPERTENSION
- stroke related to blood pressure level

chronic worsens atheroma and affect small distal arteries
reach elderly populations
majority poorly treated

**major risk factor for haemorrhagic stroke as well

How well did you know this?

Not at all

Perfectly

how can increased serum lipids, hypertension, smoking and diabetes increase the risk of stroke

all contribute to LDL-C deposition in arterial walls

increased plasma level LDL = excessive amounts of LDL in the arterial walls

= blood vessel wall atheroma

How well did you know this?

Not at all

Perfectly

what are three other risk factors for stroke not already mentioned

impaired cardiac function
- recent MI, AF

OCP (+HRT)

high oestrogen bad
progesterone only ok

hyper-coagulable states

malignancy
gentic

How well did you know this?

Not at all

Perfectly

what is the anterior blood supply to the brain

2 x Internal carotid arteries

2 x Anterior Cerebral Artery (ACA)

2 x Middle Cerebral Artery (MCA)

2 x Posterior Communicating Artery (PComA)

what is the posterior circulation to the brain

2 Vertebral arteries →1 basilar

3 pairs of cerebellar arteries (ant/post inferior, superior)

2 Posterior cerebral artery (PCA)

what do the anterior and posterior circulation join to form

the circle of willis

what are symptoms of ACA occlusion

CONTRA-LATERAL - paralysis of foot and leg - sensory loss over foot and leg - impairment of gate and stance

what are the symptoms of MCA occlusion

CONTRA=LATERAL - paralysis of face/arm/leg - sensory loss face/arm/leg - homonymous hemianopia gaze deviation to same side from paralysis to the opposite side e.g. left MCA occlusion = gaze deviation to left BUT muscles on right paralysed

what other symptoms would be seen if there was MCA occlusion on the dominant side

if stroke on dominant side (usually left) = dys/aphasia (difficulty with language or speech)

what other symptoms would be seen if there was MCA occlusion on the non- dominant side

if stroke on non-dominant side (usually right) = unilateral neglect visual and sensory agnosia (inability to recognise things) for half of external space anosagnosia - denial of hemiplegia prosopagnosia - failure to recognise faces

what is the arterial supply of the basal ganglia

the small penetrating (lacunar) arteries of the MCA

what does loss of circulation to the basal ganglia cause

lacunar ischaemic stroke

what are lacunar stroke syndromes

devoid of "cortical" signs - eg no dysphasia, neglect, hemianopia - pure motor stroke - pure sensory stroke - dysarthria - clumsy hand syndrome - ataxic hemiparesis

what structures are involved in posterior circulation symptoms

``` brainstem cerebellum thalamus occipital lobe medial temporal lobe ```

what are the symptoms of brainstem dysfunction

Coma, vertigo, nausea, vomiting, cranial nerve palsies, ataxia Hemiparesis, hemisensory loss Crossed sensori-motor deficits Visual field deficits

what should the treatment for acute ischaemic stroke aim to do

restore blood supply prevent extension of ischaemic damage protect vulnerable brain tissue

what are the first line treatments for stroke

Aspirin Heparin Neuroprotectant Tissue Plasminogen Activator (TPA) - thrombolysis Intra-arterial therapy - thrombectomy

what additional support can improve good outcome of stroke

stroke units

who makes up a stroke unit

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

what are the 4 main types of stroke

TACS - total anterior circulation stroke PACS - partial anterior circulation stroke LACS - lacunar stroke POCS - posterior circulation stroke

how would you identify LACS

pure motor >2/3 | pure sensory >2/3

how would you identify PACS

pure motor >2/3 pure sensory >2/3 1 of hemaniopia, dysphasia, neglect

how would you identify TACS

pure motor >2/3 pure sensory >2/3 MUST HAVE HEMIANOPIA + dysphasia or neglect

how would you identify POCS

all other symptoms BRAINSTEM and or CEREBELLAR SIGNS

of the 4 strokes, which has the highest death or dependency level at 6 months

TACS - 96%

what is the criteria for tissue plasminogen activator (TPA) use

<4.5 hours from symptom onset disabling neurological deficit symptoms present >60 mins CONSENT

what is the exclusion criteria for IV TPA

anything that increases the possibility of haemorrhage - blod on CT - recent surgery - recurrent bleeding - coagulation problems BP >185/>110 glucose <2.8 or >22mmolL

what happens to the benefit of TPA as time passes

decreases - if started too late can actually cause harm

what are the two types of thrombectomy

MERCI-corkscrew solitaire thrombectomy

why are TIAs like angina

warning sign as angina is to MI - TIAs are to stroke

what is the recurrence rate of stroke with TIA

10% stroke recurrence rate in the first 2 weeks after TIA

what treatment is effective in symptomatic internal carotid artery stenosis

carotid endarterectomy

after initial treatment, what should the follow management of stroke include

Prevention of stroke recurrence. Prevention of complications related to stroke. Rehabilitation. Re-integration into the community

what are some preventative second line treatments for stroke

1. anti-hypertensives 2. anti-plateletes 3. lipid lowering agents 4. warfarin for AF 5. carotid endarterectomy

what are the overall objective of stroke care

Reduce mortality. Reduce residual disability amongst survivors. Improve psychological status of patients and care-givers. Improve patient / care giver knowledge. Maximize quality of life