Stroke And Vascular Flashcards
(38 cards)
What is a stroke
A clinical syndrome characterised by rapidly developing clinical symptoms and/ or signs of focal neurological deficit lasting more than 24 hours and through to be of vascular origin
Incidence of stroke
150000 a year
Lifetime risk 1 in 6
1-2/ 1000 per year in the UK
How to diagnose stroke?
History: headaches, positive and negative symptoms; PMH of risk factors and migraines
Examination
HR, BP, O2 stats, temp
BMs- hypoglycaemia induces stroke like symptoms
CVS including carotid bruits
Resp- signs of pneumonia
Cardio
Abdo- risk of retention
Cranial nerves
Speech
PNS
Gait if possible
Scans
CT head scans are unreliable as they take time to show infarcts
+/- Carotid Doppler/ CT angiogram
ECG- AF
bloods- FBC; U+Es; LFTs; bone; clotting; BMs; cholesterol; maybe ESR; haemophilia screen and vasculitis screen
CXR- signs of aspiration
Echo+ 24 hour tape +/- prolonged monitoring
What are positive and negative symptoms of stroke?
Negative:
- weakness
- loss of motor control/ dexterity
Positive
- spasticity
- abnormal resting posture
- intrusive movement synergies e.g pins and needles
What are risk factors of stroke?
Giant Cell artheritis
PFOs
Diabetes
High cholesterol
hypertension
CAD
Valvular disease
AF
Smoking
Infection
Age
Sex younger men at more risk but women live longer so more chance later in life
Race and ethnicity
Family history
High stress
Bleeding disorders
Obesity and unhealthy life style
Classification of stroke
Ischaemic- interrupted blood supply to parts of the brain
Haemorrhagic- bleeding from artery into the brain’s parenchyma and the pressure leads to stroke like symptoms
(Does not include subarachnoid haemorrhage)
List the differences between ischaemic and haemorrhagic stroke
Bamford classification of stroke
- Lacunar- motor or sensory only
- Partial anterior circulation- 2 of: motor; sensory; cortical or hemianopia
- Total anterior circulation: all of motor; sensory; cortical or hemianopia
- Posterior circulation: heminaponia; brain stem; cerebellar
What supplies the anterior circulation of the brain
Carotid artery
What supplies the posterior circulation of the brain
bilateral vertebral arteries
TACS symptoms
Motor or sensory loss
Cortical e.g. dysphasia, neglect etc
Homonymous hemianopia- loss of half of the vision in the left side of both left and right eye
The signs match up in terms of L and R as it is coming from the same lesion
E.g. left sided motor loss with left sided homonymous hemianopia
Visual field defects in stroke
PACS
2 of the following
- motor or sensory loss
- cortical e.g dysphasia neglect etc
- Homonymous hemianopia
LACS
Pure motor (internal capsule, pons)
Pure sensory (thalamus)
Sensorimotor
Ataxic hemiparesis (pons)
Movement disorder
POCS
Isolated hemianopia
Brain stem signs
Cerebrallar ataxia
Hemiparesis
Hemisensory loss
Vertigo, vomiting
Diplopia
Facial weakness/ numbness
Dysphagia
Resp failure
Coma & death
Which type of stroke has the worst prognosis
TACS 60% chance of dying after a year and 35% dependent after a year
ICH score parameters
GCS
ICH volume in cm2
Infratentorial origin of ICH
Age
ICH score of 3 and higher > 60% chance of death within a month
Transient ischaemic attacks
Neurological signs that are consistent with a stroke that lasts for less than 24 hours
No damage on CT, may appear on MRI
Opportunity to reduce stroke risk
Fluctuating symptoms due to fluctuating swelling and blood supply around the bleed
ABCDE2 score to predict stroke 7 days post TIA
Stroke symptoms mimics
Migraines
Tumours
Abscess
Epilepsy and Todd’s palsy
Subarachnoid
Subdural
Cerebral vein thrombosis
MS
MG
Bell’s palsy
Hypoglycaemia
Sepsis
Dementia
Hypothermia
Old strokes
Where in the brain consume the most O2
grey matter due to a lot of the neural cell bodies being located there and they are the metabolic centre for nerve cells
Mitochondria present where ATP is made through oxidative phosphorylation > o2 and glucose
Energy deprived neurones die quickly
They also require a lot of energy due to the need to generate action potentials and create a concentration gradient and pump ions actively. They also send a lot of info and particles distally to the mitochondria
Synaptic transmission is the most energy consuming
Where is glycogen stored in the brain
Astrocytes, they also transfer glucose to neurons
Glucose is also a pre cursor for neurotransmitters
If the body runs out of glucose fuel it resorts to glycogenesis and breakdown of muscle for energy sources
Adaptive blood supply to the brain
Circle of Willis- helps safeguard the O2 supply from interruption by arterial blockage
Micro circulation- in chronic hypoxia (1-3 week) there is an adapted increase in capillary density in the brain to nearly double
Blood brain barrier- created by tight junctions in the endothelium of cerebral capillaries; whereby it is continuous creating the ‘barrier’
Neuromuscular component
What causes a decrease in capillary density in the brain
Hypertension
What is cerebral perfusion pressure
CPP is Amount of pressure needed to maintain blood flow to the brain
CPP helps cerebral blood flow (CBF) to be maintained constantly at a perfusion pressure of 50-150 mmHg
At the lower end of CBF, vessels are dilated and at the upper end they are constricted. In ischaemia that auto-regulation is lost and the arteries are super dilated to maximise flow
Regulated by opposing forces:
- mean arterial pressure (MAP) pushes blood into the brain
- intracranial pressure (ICP) is the force that keeps blood out 0-10 mmHg
CPP= MAP- ICP
