Neuro: stroke Flashcards
What are the two types of cerebrovascular accident?
Ischaemia or infarction of the brain tissue secondary to inadequate blood supply
Intracranial haemorrhage
What can cause disruption of the blood supply leading to a stroke or TIA?
Thrombus formation or embolus, for example in a pt with AF
Atherosclerosis
Shock
Vasculitis
What is a TIA?
Transient ischemic attack is transient neurological dysfunction secondar to ischemia without infarction (previously definied as symptoms of a stroke resolving within 24hrs)
They often precede a full stroke
What is a cresendo TIA?
A crescendo TIA is where there are two or more TIAs within a week. This carries a high risk of developing in to a stroke.
When should you suspect a vascular cause in neurology?
When symptoms are of sudden onset
Presenting features of a stroke?
Sudden weakness of limbs
Sudden facial weakness
Sudden onset dysphasia (speech disturbance)
Sudden onset visual or sensory loss
Stroke risk factors?
Cardiovascular disease such as angina, myocardial infarction and peripheral vascular disease
Previous stroke or TIA
Atrial fibrillation
Carotid artery disease
Hypertension
Diabetes
Smoking
Vasculitis
Thrombophilia
Combined contraceptive pill
What tool is used in A&E to identify stroke and what score indicates stroke is likely
ROSIER, anything above 0
Management of stroke?
Admit patients to a specialist stroke centre
Exclude hypoglycaemia
Immediate CT brain to exclude primary intracerebral haemorrhage
Aspirin 300mg stat (after the CT) and continued for 2 weeks
Once intracranial haemorrhage excluded thrombolysis or thrombectomy
What is used for thrombylisis in stroke?
Alteplase (a tissue plasminogen activator that rapidly breaks down clots)
When should alteplase be given by to reverse the effects of a stroke?
4.5 hours
What post thrombylsis complications should patients be monitored for?
Intracranial haemorrhage
Systemic haemorrhage
What is thrombectomy?
Mechanical clot removal, which may be offered within 24 hours of the honest of symptoms (depending on the location) if an occlusion is confirmed on imaging
Why should blood pressure not be lowered during a stroke?
Risk of reducing the perfusion to the brain
How is TIA managed?
Start aspirin 300mg daily.
Start secondary prevention measures for cardiovascular disease.
They should be referred and seen within 24 hours by a stroke specialist.
What is used as secondary stroke prevention?
Clopidogrel 75mg OD
Atorvastatin 80mg should be started but no immediatley
Carotid endarterectomy or stenting in patients with carotid artery disease
Treat modifiable risk factors such as hypertension and diabetes
What specialist imaging can be used to establish the vascular territory involved in a stroke?
Diffusion weighted MRI/CT
Carotid ultrasound can be used to assess for carotid stenosis
What is the gold standard stroke imaging?
Diffusion weighted MRI
Once patients have had a stroke they require a period of adjustment and rehabilitation. This is essential and central to stroke care. Who is involved as part of the MDT?
Nurses
Speech and language (SALT)
Dieticians
Physiotherapy
Occupational therapy
Social services
Optometry and ophthalmology
Psychology
Orthotics
How does an infarct appear on CT head?
Hypodense
How does cerebellar dysunction present (inc. cerbellar stroke)?
DANISH:
Dysdiadochokinesia (an inability to perform rapid alternating hand movements)
Ataxia (a broad-based, unsteady gait)
Nystagmus (involuntary eye movements)
Intention tremor (seen when the patient is asked to perform the ‘finger-nose test’)
Slurred speech
Hypotonia
Causes of cerebellar dysfunction?
Most common: Stroke, multiple sclerosis.
Other: Lyme disease, trauma to posterior fossa, alcholism, phenytoin, carbamazepine, primary tumours
What does dysphagia suggest about the nature of a stroke?
dominant cortex involvement
What is the most common type of ischemic stroke?
Middle cerebral artery territory infarcts are the most common of the thromboembolic strokes.
The presence of isolated monoparesis (pure motor stroke) suggests what classification?
Lacunar stroke LACS
TACS
A total anterior circulation stroke (TACS) is a large cortical stroke affecting the areas of the brain supplied by both the middle and anterior cerebral arteries.
All three of the following need to be present for a diagnosis of a TACS:
Unilateral weakness (and/or sensory deficit) of the face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction (dysphasia, visuospatial disorder)
PACS
A partial anterior circulation stroke (PACS) is a less severe form of TACS, in which only part of the anterior circulation has been compromised.
Two of the following need to be present for a diagnosis of a PACS:
Unilateral weakness (and/or sensory deficit) of the face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction (dysphasia, visuospatial disorder)*
*Higher cerebral dysfunction alone is also classified as PACS.
POCS
A posterior circulation syndrome (POCS) involves damage to the area of the brain supplied by the posterior circulation (e.g. cerebellum and brainstem).
One of the following need to be present for a diagnosis of a POCS:
Cranial nerve palsy and a contralateral motor/sensory deficit
Bilateral motor/sensory deficit
Conjugate eye movement disorder (e.g. horizontal gaze palsy)
Cerebellar dysfunction (e.g. vertigo, nystagmus, ataxia)
Isolated homonymous hemianopia
LACS
A lacunar stroke (LACS) is a subcortical stroke that occurs secondary to small vessel disease. There is no loss of higher cerebral functions (e.g. dysphasia).
One of the following needs to be present for a diagnosis of a LACS:
Pure sensory stroke
Pure motor stroke
Sensori-motor stroke
Ataxic hemiparesis
What does the ACA supply?
The anterior cerebral arteries supply the anteromedial area of the cerebrum.
What does the MCA supply?
The middle cerebral arteries supply the majority of the lateral cerebrum.