Disease and clinical features Flashcards
(36 cards)
Definition of a stroke
Neurological deficit related to a non-traumatic vascular event
What is the difference between a stroke and a transient ischaemic attack?
TIA is a neurovascular event with symptoms lasting less than 24 hours
Stroke more severe
What are the two main categories of stroke and what is the prevalence of each?
Ischaemic ~ 80% (Embolic, “in situ” thrombotic)
Haemorrhagic ~ 20%
note: subdural and extradural haemorrhage is excluded
What are usually the cardinal features of stroke?
Sudden onset
Identifiable risk factors
Focal clinical deficit (as opposed to global)
Negative clinical phenomena results, i.e. loss of function
Symptoms relate to arterial anatomy (calibre/site)
What is the annual incidence of strokes in the UK?
100,000 / year
What are the risk factors for embolic stroke?
Atheromatous disease
- smoking
- family Hx
- diabetes
- hypertension
Cardiac causes
- AF
- endocarditis
- shunts (patent foramen ovale, atrial septal defects)
- cardiomyopathy
Low cardiac output states
What are the risk factors for “in situ” thrombotic stroke?
Atheromatous disease
Hyperviscosity e.g. polycythaemia (excess RBCs)
Vasculitis e.g. RA, SLE, amphetamine/cocaine abuse
Thrombophilic states e.g. Factor V Leiden, pregnancy, OCP
Increased alcohol intake
What are the risk factors for haemorrhagic thrombotic stroke?
Hypertension
Anticoagulation
Thrombolysis
What are the risk factors for venous stroke?
Dehydration
Infectionn
Heart failure
Thrombophilia and thrombophilic states
What are some of the demographic risk factors for stroke?
Increased risk with age
Male > Female
Asian and african populations are more risk than caucasians
List the different type of strokes classified by its anatomy
Total anterior circulation strokes
Posterior anterior circulation strokes
Posterior circulation strokes
Watershed strokes
Lacunar strokes
Venous strokes
What arteries cause a total anterior circulation stroke?
Anterior cerebral artery and middle cerebral artery
Also Ophthalmic artery if oclusion occurs in internal carotid artery
What causes a partial anterior circulation stroke?
Any part of region supplied by ACA or MCA
What causes a posterior circulation stroke?
Any part of region supplied by PCA (via basillar artery)
What is a watershed stroke?
Occurs at a watershed (area where arteries join) between PCS and ACS
What is a lacunar stroke?
Small stroke affecting areas supplied by lenticulostriate arteries (from MCA) in pons, basal ganglia, thalamus +/- internal capsule
What is a venous stroke?
Causes by venous thrombosis and resultant “backing up” of blood in cerebral arteries
- often don’t respect arterial territories e.g. may produce signs associated with ACS and PCS by affecting regions of both territories
What are the typical presenting features of an Anterior Circulation Stroke?
Hemiplegia (if affecting motor cortex on one side, mostly MCA)
Language dysfunction
Apraxia if damage to pre-motor cortex/supplementary motor area
Insognia due to damage to posterior parietal cortex (integrates sensory info and inputs to motor areas)
More specific MCA signs
- hemianaesthesia
- hemianopia
What is apraxia?
Inability to carry out complex tasks
What is insognia?
Denial of non-dominant side of body
What is hemianopia?
Loss of vision to one side of both eyes
What are the typical presenting features of a Posterior Circulation Stroke?
Bilateral visual loss
Diplopia
Dysarthria
Unsteadiness
Dysphagia
Amnesia
What are the typical presenting features of an internal capsule stroke (lacuna stroke in internal capsule)?
Most common stroke
Pure motor hemi/monoplegia
Pure sensory hemianaesthesia
What are the signs and symptoms of a cerebral infarction?
Contralateral hemiplegia/paresis (+/- aphasia if dominant hemisphere) developing over minutes/hours
- limbs firstly flaccid and areflexic
- become less weak and hyperreflexic over days/weeks
No headache (usually)
No loss of consciousness
