Stroke Flashcards
What is a stroke?
Acute neurological dysfunction of a vascular cause
What are the main risk factors for stroke?
▪️ Hypertension
▪️ Diabetes
▪️ Alcohol
▪️ Cardiac disease
▪️ TIA
▪️ Older age
▪️ Male
▪️ Smoking
▪️ Obesity
▪️ Hyperlipidaemia
▪️ Physical inactivity
How can atherosclerosis lead to ischaemic stroke?
▪️ Narrowing and hardening of blood vessels with plaque build up
▪️ Substances in plaque attract platelets
▪️ This builds until a blood clot is formed which blocks the vessel
What are the current major issues surrounding stroke in the UK?
▪️ One every 5 minutes
▪️ Large proportion have depression or disability
▪️ Increased likelihood of unemployment
▪️ Only 8 out of 10 people eligible receive thrombolysis
▪️ Lack of psychologist access
How does stroke incidence change as we age?
It increases
What are the two main types of stroke?
▪️ Ischaemic
▪️ Haemorrhagic
What is FAST?
▪️ Face, Arm, Speech, Time to call 999
▪️ Rapid ambulance protocol to triage patients for thrombolysis
▪️ ~82% sensitivity and specificity
What speech problems may be apparent in someone who is having a stroke?
▪️ Dysphasia (expressive/receptive/conductive)
▪️ Dysarthria (muscle weakness)
▪️ Dyspraxia of speech (difficulty coordinating movements for speech)
▪️ Cognitive communication disorder
What are the main categories of stroke mimics?
▪️ Systemic problems with CNS effects (e.g., hypoglycaemia, delirium, ‘decompensation’)
▪️ Primary CNS problems (e.g., focal epilepsy, MS, functional presentations)
▪️ ENT (e.g., labyrinthine disturbances with nausea and vertigo)
How can you typically differentiate stroke from partial (focal) epilepsy?
The former usually causes negative phenomena (e.g., weakness) whilst the latter often produces positive phenomena (e.g., clonus)
What can be used to treat acute ischaemic stroke or pulmonary embolism?
IV alteplase as soon as possible, ideally within 3-4.5 hours of symptoms (thrombectomy)
What is tissue Plasminogen activator (tPa)?
An enzyme involved in breaking down blood clots so can be used for intravenous thrombolysis
Alteplase = biosynthetic form
What is tPa use in stroke associated wiht?
▪️ Better outcome
▪️ 12% increase in minimal/no disability
▪️ Benefit in all subgroups
Damage to what brain area may present with Broca’s aphasia?
Motor speech area in frontal lobe of dominant hemisphere (left), particularly inferior frontal gyrus
Damage to what brain area may present with Wernicke’s aphasia?
The superior temporal lobe, typically also of the dominant hemisphere
What is a phonemic paraphasia?
Sound substitution or rearrangement but still resembles intended word (e.g., “bap” for “map”)
What is semantic paraphasia?
Entire word is substituted for one of similar meaning (e.g., “knife” for “fork”)
What are the characteristic symptoms of Gerstmann syndrome?
▪️ Finger agnosia
▪️ Dyscalculia
▪️ Dysgraphia
▪️ R-L disorientation
How can you test for language deficits following stroke?
▪️ Understanding (e.g., multiple stage commands)
▪️ Expression (just listen)
▪️ Naming
▪️ Repetition
▪️ Reading
▪️ Writing
▪️ Talk about a scene - can also see emotive features and safety awareness
What is the most common visual problem following stroke?
Homonymous hemianopia (visual field loss in same half of both eyes)
Damage to which area may result in Gerstmann syndrome?
Inferior parietal lobe of the dominant hemisphere, specifically around the angular gyrus
What is visual neglect?
Disorder of attention whereby the individual shows a lack of response to one half of their visual field, unexplained by primary damage to the visual system
How can neglect be subdivided/described?
▪️ Affected space (peripersonal, personal, extrapersonal)
▪️ Mode of output (sensory or motor)
▪️ Sensory modality (visual, somatosensory, auditory)
When does partial or complete recovery from neglect after stroke typically occur?
In the first month
What is the presence of neglect following stroke associated with?
▪️ Delayed recovery (if unilateral)
▪️ Problems with ADLs
▪️ Greater risk of falls
▪️ Longer stays in rehabilitation
▪️ Need for more assistance at discharge
What is the presence of delirium following stroke associated with?
▪️ Worse effects of stroke
▪️ Greater mortality, both inpatient and at 12-months
▪️ Greater functional impairment
▪️ Increased risk of dementia
▪️ More likely to be discharged to a nursing home/institution
How can we reduce the risk of delirium post-stroke?
▪️ Treat primary mechanism (e.g., inflammation)
▪️ Better sleep
▪️ Improve environment
▪️ Recovery at home
How might a brain stem stroke (basilar artery) present?
▪️ Severe impact
▪️ Locked in syndrome
▪️ Major sensory and motor deficits
▪️ Little cognitive dysfunction
How does arterial fibrillation increase the risk of stroke?
Increases risk of blood clot formation
What brain area is involved in neglect?
The parietal lobe, contralateral to the side of extinction
What is Anton’s syndrome?
Denial of visual loss due to cortical blindness, typically due to bilateral lesions of the primary visual cortex
What are the four clinical classifications of stroke according to the Oxfordshire Community Stroke Project (OCSP) classification?
▪️ TACS - total anterior circulation stroke
▪️ PACS - partial anterior circulation stroke
▪️ LACS - lacunar syndromes
▪️ POCS - posterior circulation strokes
What are the benefits of the OCSP?
▪️ Clinically based
▪️ Helps with aetiology
▪️ Predicts volume of brain involved
▪️ ‘Predicts’ recovery
BUT not validated in hyperacute situation
What are the main subtypes of the TOAST classification of stroke?
- Large artery atherosclerosis
- Cardioembolism
- Small artery disease
- Other determined aetiologies
- Undetermined aetiology
What is small vessel disease?
A condition that causes the narrowing of the small blood vessels and damage of their walls
What are the main risk factors for small vessel disease?
▪️ Hyaline arteriosclerosis (accumulation of various serum proteins, thickening the walls)
▪️ Hypertension, diabetes, smoking
What are the proposed causes of small vessel disease?
▪️ Incorporation of plasma proteins into the vessel wall causes breakdown of the BBB
▪️ Collagen replaces smooth muscle cells and reduces distensibility of the vessels (less elastic, increased risk of damage)
Which structures in the CNS are most commonly affected by SVD?
▪️ Lenticulostriate perforating branches
▪️ Basilar and posterior artery perforators
▪️ Periventricular white matter
What are lacunar infarcts?
Small infarcts caused by occlusion of a singular penetrating branch of a large cerebral artery
What neurological clinical consequences may be seen with SVD?
▪️ Lacunar strokes
▪️ Cognitive change/dysfunction
What are the main types of lacunar infarct?
▪️ Pure motor
▪️ Pure sensory
▪️ Motorsensory
▪️ Ataxic hemiparesis
▪️ Clumsy hand-dysarthria syndrome
What techniques can be used for blood vessel imaging in the brain?
▪️ Carotid dopplers
▪️ CT angiogram
▪️ MR angiogram
▪️ Formal angiogram - digital subtraction angiography
(Perfusion computed tomography - PCT)
How might a stroke to the posterior circuit present?
▪️ Constellation of brainstem symptoms
▪️ Altered consciousness
▪️ Nausea/vomiting
▪️ Crossed signs
What intervention might you consider for a middle cerebral artery stroke?
Decompressive hemicraniectomy
What is a carotid artery dissection and how does it typically present?
▪️ Tear or separation of layers of the carotid
▪️ Can be non-traumatic or with mild trauma
▪️ Relatively common cause of stroke in younger patients
▪️ May be associated with sequelae such as stroke, TIA, or subarachnoid haemorrhage
What percentage of strokes are accounted for by intracerebral haemorrhage?
~15%
What risk factors are associated with spontaneous intracranial haemorrhage (sICH)?
▪️ Systemic arterial hypertension
▪️ Alcohol abuse
▪️ Male
▪️ Increasing age
▪️ Smoking
What secondary vascular changes may be seen with ICH?
▪️ Small vessel disease
▪️ Arterial aneurysms
▪️ Arteriovenous malformation
