Neurology Flashcards
Define cerebrovascular event (stroke)
A clinical syndrome caused by disruption of blood supply to the brain (due to infarction or haemorrhage), characterised by rapidly developing signs of focal or global disturbance of cerebral functions, lasting for more than 24 hours or leading to death
Define ischemic stroke
An episode of neurological dysfunction caused by focal cerebral, spinal, or retinal infarction (cell death due to lack of blood supply)
What are the 5 types of ischemic stroke?
- Large vessel disease (atherosclerosis/thrombosis)
- Small vessel disease (microathermoma, lacunes)
- Cardioembolic (caused by AF, endocarditis, mural thrombus)
- Other (rare causes e.g. vasculitis, venous thrombosis, carotid dissection)
- Undefined
Define stroke due to primary intracerebral haemorrhage
Rapidly developing clinical signs of neurological dysfunction because of a focal collection of blood within the brain parenchyma or ventricular system, which is not caused by trauma
*secondary intracerebral haemorrhage = due to trauma, blood thinners etc.
Define stroke due to subarachnoid haemorrhage
Rapidly developing signs of neurological dysfunction and/or headache (thunderclap) because of bleeding into the subarachnoid space, which is not caused by trauma
What are the risk factors for strokes?
Lifestyle factors:
- smoking
- alcohol misuse
- physical inactivity
- poor diet
Established CVD:
- hypertension
- AF
- infective endocarditis
- IHD
- congestive heart failure
- structural defects (valve disease)
Other medical conditions:
- migraine
- hyperlipidaemia
- diabetes mellitus
- hypercoagulable disorders
- connective tissue disorders
- taking combined oral contraceptive
Non-modifiable factors:
- older age
- male sex
- personal/family history of stroke/TIA
- lower level of education
What are the signs/symptoms of a stroke in the anterior circulation?
Either hemisphere (symptoms contralateral):
- hemiparesis (upper limb = MCA, lower limb = ACA)
- hemisensory loss (upper limb = MCA, lower limb = ACA)
- visual field defect
Dominant hemisphere (usually LEFT hemisphere)
- language dysfunction (expressive/receptive dysphasia, dyslexia, dysgraphia)
Non-dominant hemisphere (usually RIGHT hemisphere)
- visuospatial dysfunction (geographical agnosia, dressing apraxia, constructional apraxia)
- anosognosia (impaired understanding of their illness, neglect of paralysed limb, denial of weakness)
What are the signs/symptoms of a stroke in the posterior circulation?
- Vertigo
- Ataxia, unsteadiness, imbalance
- Visual disturbance (homonymous hemianopia, diplopia)
- Slurred speech
- Disorder of perception
- Headache
- Nausea and/or vomiting
- Motor and sensory dysfunction
- Cranial nerve dysfunction
- Dysarthria/dysphasia
- Others e.g. memory loss, confusion, reduced consciousness
What investigations are needed for a stroke?
- CT head (1ST LINE, without contrast, ideally within 1 hour)
- MRI brain with diffusion weighted imaging (GOLDSTANDARD)
- Blood tests (FBC, U&E, ESR, TFTs, glucose, lipids, HIV, syphilis: to asses general health and exclude other causes)
- ECG (look for arrhythmias and cardiac causes)
- ECHO (may show mural thrombus, valvular lesions)
- Carotid Doppler ultrasound, or CT/MRI angiogram if thrombectomy indicated (asses carotid artery stenosis and location of occlusion)
What are the treatments for an ischemic stroke?
General:
- ABCDE
- maintain oxygen, hydration, blood pressure and glucose
- assess swallow
Antiplatelets:
- only once haemorrhagic stroke is ruled out
- aspirin 300mg (or clopidogrel)
Thrombolysis:
- only within 4.5 hours of onset and once haemorrhagic stroke is ruled out
- most effective in 1st 90 mins
- using alteplase (tissue plasminogen activator)
- CI if uncertain timing, recent head injury/surgery, cerebral neoplasm, recent GI surgery, BP >180/110, on anticoagulant, seizure, hypodensity on CT
Surgical:
- thrombectomy (for confirmed large vessel occlusions, within 6 hours of symptom onset)
- decompressive hemicraniectomy (for large MCA infarcts with severe deficits, within 48 hours of symptom onset)
What is the primary prevention for strokes?
Control risk factors:
- asses and screen for hypertension, DM, hyperlipidaemia, cardiac disease (QRISK)
- smoking cessation
- exercise
- dietary advice
- weight management
- avoid alcohol excess
Drug treatment:
- control hypertension
- aspirin + statin following MI
- DOAC in AF (with high risk CHADS-VASc score)
- warfarin in valvular disease/replacement
What is the secondary prevention for a stroke?
- Lifestyle changes
- Investigate and treat risk factors: hypertension, hyperlipidaemia, cardiac disease, carotid artery stenosis, etc.
- Short term antiplatelets: aspirin 300mg for 2 weeks
- Long term antiplatelets: clopidogrel
- Anticoagulants if cardiac cause: warfarin/DOAC
- Statin (if evidence of atherosclerosis)
- Surgical: carotid endarterectomy or stenting (if carotid stenosis)
Define TIA
Transient (less than 24 hours) neurological dysfunction caused by focal cerebral, spinal, or retinal infarction
What are the signs/symptoms of TIA?
*symptoms come on suddenly and usually resolve after 1 hour but can persist up to 24 hours
Focal neurological defects:
- unilateral weakness/sensory loss
- dysphasia
- ataxia, vertigo, loss of balance
Cranial nerve defects
Amaurosis fugax (sudden transient loss of vision in one eye)
What is the management of a TIA?
- Lifestyle changes
- Assess and control cardiovascular risk factors (blood pressure, lipids, glucose)
- Antiplatelets: short-term aspirin, long-term = clopidogrel
- Anticoagulants (warfarin/DOAC) is cardiac cause
- Carotid endarterectomy/stenting (reduce stenosis)
Describe an extradural haemorrhage
Bleeding between the dura and bone (usually skull, but may be spine), usually with a traumatic cause due to fractures temporal/parietal bone damaging the middle meningeal artery
What are the clinical features of an extradural haemorrhage?
- May present with traumatic injuries
- Can have a ‘lucid period’ lasting hours-days
- Symptoms of headache, nausea/vomiting, seizures, reduced GCS, CSF leak
- Signs of bradycardia +/- hypotension (raised ICP), unequal pupils, facial nerve injury, focal neurological deficits
- Features of cord compression if haematoma in the spinal column (weakness, numbness, altered reflexes, incontinence)
How does an extradural haemorrhage appear on a CT scan?
- Acute (fresh) blood appearing hyperdense (bright wight)
- Convex - does not conform to surface of the brain, limited by dural attachments
- Involves compression of the brain (midline shift of falx cerebri, compression of lateral ventricles)
- Skull fracture may be seen (or picked up on X-ray)
What is the management of an extradural haemorrhage?
- ABCDE
- IV mannitol or hypertonic saline to reduced ICP
- Conservative management for small bleeds
- Burr hole craniotomy for larger bleeds
Describe a subdural haemorrhage
Bleeding between the dura and arachnoid, usually with a traumatic cause due to rupture of the bridging cranial veins by shearing forces (e.g. acceleration-declaration in RTA), with risk factors being older age (cerebral atrophy), alcoholism, non-accidental injury in infants, and anticoagulant use
