Stroke Flashcards
What are the crucial steps in investigating a suspected stroke patient?
- Is this actually a stroke (mimics/chameleons)
- Cause (haemorrhage or embolus)
- Location (which artery)
- Complications (any ongoing or likely)
- Investigation
- Intervention
- Information and discharge planning
What is a stroke mimic and what are the most common examples?
Non-Vascular conditions that commonly present as/are mistaken for strokes.
BEHIINDD: Brain (masses, tumours, bleeds), Epilepsy, Hypo(glycaemia, natremia), Intoxication, Infection (meningitis), Neuro (migraines, MS), Disc Prolapse, Disection
What features strongly suggest Stroke Syndrome?
Always true in SS:
- Sudden onset (due to sudden loss of blood supply causing sudden drop in O2 and glucose, causing sudden loss in membrane polarity)
- Focal (affects one NV territory)
- Predominantly negative (loss of functions)
Generally true in SS:
- Sensory/Motor symptoms do not Migrate (as they might do in migraines or seizures)
- Non-stereotypical (i.e. do not repeat themselves)
Often true:
- CVS risk factors
What are the 4 Oxford Community Stroke Project Classifications?
- TACS: Total Anterior Circulation Syndrome
- PACS: Partial Anterior Circulation Syndrome
- POCS: Posterior Circulation Syndrome
- LACS: Lacunar Syndrome
Describe the cause and features of a TACS Stroke?
ICA or Proximal MCA occlusion, causes all 3 of:
- Hemiparesis
- Higher cortical dysfunction (dysarthria, VS neglect)
- Homonymous Hemianopia
Describe the cause and features of a PACS Stroke?
MCA branch occlusion, causes either:
- Isolated Higher cortical dysfunction
OR
- 2 of HH, Cortical Dysfunction or Hemiparesis
Describe the cause and features of a POCS Stroke?
Caused by occlusion of the PCA, Vertebral, Basilar or Cerebellar vessels, leading to any of:
- 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
Describe the cause and features of a LACS Stroke?
Occlusion of a small penetrating artery, causing either a:
- Pure motor stroke
- Pure sensory stroke
- Sensorimotor stroke
- Ataxic hemiparesis
- Clumsy hand dysarthria
In which condition might you see Migrating stroke symptoms?
Capsular Warning Syndrome.
Occurs due to the odd shape of the LS arteries, MCA blood flow reduction causes hypoperfusion of LS arteries causing fluctuating and migrating stroke symptoms.
In which condition might you see Stereotyping stroke symptoms?
Intracranial Stenosis.
Symptoms can be identical to stroke BUT often paired with symptoms of general, systemic hypoperfusion e.g. palpitations, dizziness, pallor, clamminess. Requires angiography to confirm.
What methods should be use to determine Stroke vs Stroke mimic?
Some conditions can be recognised through history e.g. BPV, TGA, Bell’s Palsy, Vestibular Neuronitis.
Some are readily apparent on basic neuroimaging e.g. haematomas, MS, brain tumours, abscesses.
Some require more thorough, detailed investigation e.g. migraine with aura, forms of epilepsy, functional syndrome
How would you distinguish BPV from Stroke?
BPV is…
- Associated with changes in position
- Associated with vomiting
- Dx with positive Dix/Halpike test
- Therapeutic benefit with Epley maneuvre
How would you distinguish Vestibular Neuronitis (Labyrinthitis) from Stroke?
Present similarly to BPV with dizziness and vomiting.
- Confirm with positive head thrust test.
N.B: Isolated vertigo is unlikely to be stroke but many strokes cause vertigo (+ other symptoms)
How would you distinguish TGA from Stroke?
Isolated loss of episodic memory (but not biographical or procedural) is likely to be TGA.
How would you distinguish Migraine w/ Aura from Stroke?
Can present with similar neurological symptoms (e.g. blurring of vision, loss of sensation, difficulty concentrating or speaking). But…
- Will tend to be migrating
- Will tend to be fluctuating
- Will tend to be less sudden in onset (20 mins)
What causes Migraine with Aura?
Cortical Spreading Depression (CSD), a phenomenon that also explains the differences between MwA and Stroke:
- Altered but not entirely switched off brain activity, causing positive symptoms.
- Moves around the brain, causing migrating/fluctuating symptoms with a gradual onset.
What are apparent neurological deficits?
Areas of significant Gliosis which can maintain normal function in optimal physiological state, but not when under any form of stress e.g. infection, MI, sepsis, hypoxia, hypoglycaemia, stress, fatigue, dehydration etc, causing stroke symptoms.
What are some common causes of Stroke in young people?
- Vertebral Artery Dissection (common in some genetic CT disorders such as Marfan’s or Ehlers-Danlos)
- Fibromuscular Dysplasia at Carotids
- Dyslipidaemia
- Thrombophilia
Also cocaine.
What sort of targeted assessment tools should be considered if trying to identify the cause of a stroke?
- ECG (or 24h tape)
- Echo (TT or TO)
- Carotid US
- Thrombophilia screen
- Angiography
- Plasma viscosity/ TA biopsy
What is the most likely cause of a PACS stroke?
Almost always embolization into branches of the MCA or ACA, investigations should be focused on finding the source of the embolus e.g. carotid artery, heart.
What is the TOAST classification of strokes, give some examples of each.
Essentially, strokes can be caused by many things. TOAST groups all strokes into 5 larger groups:
- Large artery atherosclerosis (e.g. artherothrombosis in the carotid arteries).
- Cardiac emboli (e.g. AF, flutter, MI, valve prolapse, endocarditis, pulmonary vein thrombosis).
- Small Vessel Occlusion (e.g. lacunar strokes caused by hypertension or DM).
- Other determined (e.g. arterial dissection, fibromuscular dysplasia, cerebral venous thrombosis
- Cause undetermined
What are some common complications of Stroke?
- Recurrent stroke
- Complications associated with immobility (e.g. bed sores, VTE, constipation)
- Raised ICP (malignant oedema, hydrocephalus)
- Infections
- Mood and cognitive disorders
- Post stroke fatigue
- Post stroke pain
- Spasticity, Contractures
- Secondary Epilepsy
- SEPSIS
What is the difference between a stroke complication and a stroke impairment?
Impairments = the result of neuronal damage from stroke
Complications are issues aside of that.
Strokes normally cause impairments but rarely kill people, most risk of death comes from complications.
What steps can be taken to reduce the risk of stroke complications?
- Anticipation
- Thorough monitoring (Daily review of obs, meds, mood, chest, legs, bowels, urine function, impairment progression)
- Timely and regular bloods (mostly CRP and clotting)
- Mobilise and Exercise the patient ASAP
Why is maintaining optimum physiological state vital to the care of a stroke patient?
- Reduces risk of complications inc. infection and mood issues
- Helps with maintenance of the ischaemic penumbra (area around the lesion which takes part in neuroplasticity), therefore has significant effect on recovery.
Want to avoid: Hypoxia, Hypoglycaemia, Hypotension, Anaemia, Sepsis
What is the typical care pathway for a stroke patient?
- Admission to stroke unit
- Revascularisation therapy (?)
- Optimise physiology on the wards, prevent and look for complications
- Nutritional support
- Secondary prevention
- Rehab
What are the two revascularisation options and what are their windows?
IV Alteplase:
- 4.5 hour window
- Rapid assessment to confirm stroke, check for contraindications, CT head, give bolus)
Thrombectomy:
- 6 hour window (although can do up to 24 depending on what shows on CT, apparently)
- Only selected patients with large vessel occlusion
- CT angiogram can be used to guide/assess
N.B: You can also quite happily give a patient Alteplase immediately then send them for Thrombectomy.
What is the NIH Stroke Scale?
Common diagnostic method for quickly assessing the severity of a stroke experienced by a patient.
Gives a quant value for neurological impairments suffered by stroke patients.
What are the main Secondary Prevention measures used in stroke patients?
- Antithrombotic therapy
- BP control (130/80 aim)
- BM control (HbA1c < 7)
- Lipid control
- Carotid endarterectomy (and other aetiology specific options)
- Lifestyle (smoking cessation, drinking, diet, sleep)
What is meant by Haemorrhagic Transformation of an Ischaemic Stroke?
Complication of IS where BBB dysfunction causes bleeding (commonly after thrombolytic therapy but can happen independently)
What anticoagulation drugs are commonly used in AF to prevent stroke risk (or as secondary prevention)?
DOACS are now more common than Warfarin e.g. Apixoban, Rivaroxiban).
Always work out CHADSVASC and HASBLED first
What is the issue with wake up strokes?
Impossible to determine when they occurred, therefore hard to give thrombolysis. Require good collateral history and intervention ASAP otherwise can’t justify (bleed risk too high).
Why is revascularisation therapy so effective in stroke management?
Preserves at risk neural tissue, allowing for neuroplasticity
What is the BEFAST system and what is it’s purpose?
Rapid screening tool used by patients/their family/paramedics to ascertain which patients need to go to stroke ED.
Balance, Eyes, Face, Arms, Speech –> Time to call 999
What is a RAP team and what steps do they take in acute stroke management?
Rapid Assessment Protocol.
- Clinically confirm diagnosis (stroke), Determine whether thrombolysis is indicated (time window), IV access, bloods, weight, send to CT scan
- Look for contraindications
- Consent
- Imaging
- Bolus
What is the indication for IV thrombolysis with Alteplase?
- Ischaemic stroke, 4.5 hours of onset
- ‘Disabling Impairments’ e.g. vision loss, dysphasia, inability to self care
- Patient has no contra-indications
(DI = a subjective term and need to bear in mind patient when deciding whether to thrombolysis or not e.g. if only symptom is loss of finger dexterity, may not be Disabling for a 96 year old but would for a 36 year old concert pianist).
What are the absolute contraindications for IV Alteplase thrombolysis?
- Blood pressure > 185/110 mmHg after 2 attempts to reduce levels
- Surgery or trauma within the last 14 days
- Stroke within the last 14 days
- Active internal bleeding
- Severe haematology abnormalities
INR>1.7 or APTT>40 - On dabigatran with abnormal APTT or thrombin time >100 seconds
- On rivaroxaban / apixaban / edoxaban
- On high-dose LMWH
- Platelet count <50 x 109/L
INR>1.7 or APTT>40 - Arterial puncture at a non-compressible site or LP in last 7 days
- Symptoms suggestive of SAH, even if CT normal
- Infective endocarditis, pericarditis or presence of ventricular aneurysm related to recent MI
- Childbirth within the previous 4 weeks
- Acute pancreatitis
- Severe liver disease, including hepatic failure, cirrhosis, portal hypertension, oesophageal varices and active hepatitis.