Stroke Flashcards
What are the relative contraindications to thrombolysis? (5)
Already on anticoagulants
Known coagulopathy
Active diabetic haemorrhagic retinopathy
Suspected intracardiac thrombus
Major surgery / trauma in the preceding 2 weeks
What are the absolute contraindications to thrombolysis that relate to bleeding? (7 - quite a few)
Active bleeding
Suspected SAH
Previous intracranial bleed
GI bleed in the last 3 weeks
LP in past 7 days
Uncontrolled HTN I.e. above 200 systolic
Oesophageal varices
What are the absolute contraindications to thrombolysis that DO NOT relate to bleeding? (4)
Pregnancy
Intracranial neoplasm
Stroke/ traumatic brain injury in past 3 months
Seizure at onset of stroke
What are the time frames for thrombolysis and thrombectomy following a stroke?
Thrombolysis = within 4 hours
Thrombectomy = 4-6 hours
What is the definition of a stroke?
The sudden onset of focal symptoms that are mainly negative and can be explained by hypo perfusion to a specific vascular territory
How do ischaemic and haemorrhagic strokes lead to hypo perfusion?
I = blocked artery
H = Bleeding
What is the TOAST classification?
5 Types of ischaemic stroke
1) Large artery atherosclerosis (embolus or thrombus)
2) Cardioembolism (high or med risk)
3) Small vessel occlusion
4) Stroke of other aetiology
5) Stroke of undetermined origion
What is the NIHSS?
Way to quantify severity of stroke
Higher score = more severe BUT the dominant side can give a higher score for the same amount of neuronal death
What is the CHADSVASC?
Way of assessing embolic stroke risk. Score of 2 = 2.2% risk
Congestive Cardiac Failure (1) HTN (1) A2 = Age 65-74 or 75 (1) Diabetes (1) S2 = Stroke/TIA/VTE (2) V Ascular disease (1) Sex Category Female (1)
What is the HASBLED?
Way to assess risk of bleeding when anti coagulated (all score 1 each)
HTN A3 - abnormal LFTs, renal failure, alcohol use (1 each) Stroke Bleeding Labile INR Elderly >65 Diabetes
Where does the anterior cerebral artery supply? How would an ACA infarct present?
Medial hemispheres = lower limbs and genitals
Contralateral motor deficit - initial flaccidity that becomes spastic
Where does the middle cerebral artery supply? How would an MCA infarct present?
Lateral hemispheres = face and upper limbs
Contralateral motor and sensory deficits
internal capsule affected
Where does the posterior cerebral artery supply? How would a PCA infarct present?
Occipital lobe = vision
Visual defects - contralateral homonymous hemianopia with macular sparing as macula is supplied by the MCA
Define a Transient Ischaemic Attack
An ischaemic neurological event with similar symptoms to a stroke i.e. relate to a particular vascular territory but symptoms resolve within 24 hours (in real life it is quicker so usually 1-2 hours)
What is the ABCD2?
A method of stratifying risk of a stroke following a TIA (I don’t think it is actually used any more)
Age >60 (1)
BP >140 (1)
Clinical Features (unilateral weakness (1), speech disturbance (1))
Duration >1 hour (2), 10-59 mins (1). Diabetes (1)
> 4 = high risk
What is now used instead of ABCD2?
Anyone in past week is high risk
Low risk is >1 week
Which bed and blood tests should be done if someone presents with a TIA?
Bed = BP (baseline obs)
Blood = Lipids, glucose, U&E, FBC, VBG
What imaging should be done in TIA clinic?
ECG - AF?
DWI MRI - shows acute changes or areas of ischaemia and is sensitive for up to 2 WEEKS
CT - shows older changes i.e. after 4 hours and rules out bleeding
CUSS - >50% occlusion = carotid endartectomy?
What is the conservative management of a TIA?
Urgent referral to TIA clinic as risk of recurrent stroke is 10%
No driving for 4 weeks!!!!
Lifestyle - weight loss, stop smoking
What is the primary medical management of a TIA?
Aspirin 300mg for 2 weeks (+PPI if needed)
Switch to Clopidogrel 75mg PO
What is the secondary medical management of a TIA?
Manage HTN
Statin
What is the surgical management of a TIA?
Carotid endarterectomy if >50% stenosed and are of an acceptable surgical risk
What are the main 6 clinical features of a stroke/TIA?
Focal
Sudden Onset
Mainly -ve symptoms
Relates to a vascular territory
Symptoms don’t migrate
Stereotyping is not usual
Give 4 general clinical features of a stroke/TIA
Confusion
Headache
Dizzy/vertigo/Syncope
Nausea and vomiting
Give 5 neurological features of a stroke/TIA
Sensory loss/parasthesia Initial hypotonia that becomes hypertonic Cranial nerve deficits Homonymous hemianopia Speech - dysarthria, aphasia, dysphasia
Which blood vessel is associated with total anterior circulation syndrome (TACS)?
Proximal MCA
ICA (which leads to MCA anyway)
What are the clinical features of a TACS?
Hemiparesis
Higher cortical dysfunction e.g. dysphasia AND homonymous hemianopia
Which blood vessel is associated with partial anterior circulation syndrome (PACS)?
MCA +/- branches
What are the clinical features of a PACS?
Isolated higher cortical dysfunction
OR
Higher cortical dysfunction, 2x hemiparesis, hemianopia
Which blood vessel is associated with posterior circulation syndrome (POCS)?
Posterior circulation (surprisingly)
PCA, basilar, vertebral, cerebellar arteries
What are the clinical features of a POCS?
Isolated hemianopia OR
Brainstem/cerebellar symptoms
Which blood vessel is associated with Lacunar syndrome (LACS)?
Lenticulostriate arteries (branch of MCA)
OR
Small penetrating artery occlusion
What are the clinical features of a LACS?
Isolated motor OR
Isolated Sensory OR
Sensorimotor OR
Ataxic hemiparesis OR
Clumsy hand dysarthria
Define stereotyping
Episodic recurrence of symptoms in the same way each time e.g. capsular warning syndrome or intracranial stenosis
What is capsular warning syndrome?
Intermittent reduction in MCA perfusion so reduced flow to the lenticulostriate arteries
Get intermittent symptoms rather than a complete resolution
Usually LACS
What is intracranial stenosis?
Seen when there is another cause of generalised hypo perfusion so get that kind of symptoms e.g. dizziness, pallor
What are the 3 types of stroke mimics?
Can be identified with imaging e.g. tumour, MS
Have secure features that distinguish from stroke e.g. BPPV, syncope, transient global amnesia
Can be distinguished if all info is available e.g. migraine + aura, focal seizures
What is the mechanism of action of Warfarin?
Acts on Vit K dependent clotting factors (IX, X, VII and Prothrombin)
Inhibits reductase that regenerates active vitamin K = factors don’t forms
SO acts on intrinsic and extrinsic pathways = prevents initiation and amplification of the cascade
What are 4 important things to remember when prescribing warfarin?
Requires 3 days to start working so have to cover wit LMWH during this time as become pro-thrombotic
Target INR is 2-3
CYP450 metabolised
Teratogenic
What is the mechanism of action of Heparin?
LMWH = Acts on Factor Xa, accumulates in renal failure
Unfractionated = Acts on Antithrombin III. Needs protamine sulphate to reverse + risks heparin induced thombocytopenia
What is the mechanism of action of DOACs?
Dabigatran = acts on Thrombin
Rivaroxaban, Apixaban etc = Acts on Factor Xa
What are the positives and negatives of DOACs?
+ves = more reliable and equally effective as Wardarin, don’t require regular monitoring, lower risk of intracranial haemorrhage [than warfarin]a
-ves = Higher risk of GI bleeding, CI if renal impairment or pregnant
What are the non-modifiable risk factors for stroke?
Age
Thrombophilia
Migraine + Aura + COCP (younger pt)
What are the modifiable risk factors for stroke?
HTN
Cardiovascular disease
AF
Smoking
T2DM
Define aphasia
A selective impairment of language or the cognitive processes that underlie language
What is Broca’s aphasia? Which bit of the brain is damaged?
Non-fluent, poorly articulated, and agrammatic speech output (in both spontaneous speech and repetition) with relatively spared word comprehension.
Can understand what you’re saying but can’t communicate coherently back
left posterior inferior frontal cortex, in the distribution of the SUPERIOR division of the left middle cerebral artery (MCA).
What is Wernicke’s aphasia? Which bit of the brain is damaged?
Fluent but meaningless speech output and repetition, with poor word and sentence comprehension.
Don’t understand what you’ve said and just say randomish words
Posterior superior temporal cortex, in the distribution of the INFERIOR division of the left MCA.
Give 4 differential diagnoses for a stroke
Hypoglycaemia/DKA
Hemiplegic migraine
Post-ictal (could still be a stroke esp if haemorrhagic)
Previous cerebrovascular accident + systemic illness
What are the targets for blood pressure control, acutely and long term?
Acute = <180 if ischaemic, <140 if haemorrhagic
Long term = <130/80
What is the definition of malignant MCA syndrome?
Rapid neurological deterioration due to the effects of space occupying cerebral oedema or haemorrhagic transformation following a middle cerebral artery (MCA) territory stroke
How would a malignant MCA present? (4)
Acute onset of left sided hemiplegia.
No loss of conscience,
Patient is agitated and anxious.
CVS risk factors
What are the 3 layers of meninges from out to in?
Outermost = Dura mater - tough and fibrous
Middle = Arachnoid mater - Contains CSF in subarachnoid space
Innermost = Pia mater - protection from chemicals/infections as adheres closely to brain and spinal cord
What are the 2 layers of dura?
Periosteal and meningeal
They separate to contain the dural venous sinuses
What is the function of the arachnoid mater?
Buffer layer and allows the brain to be weightless
Define an aneurysm
A sac formed by the localised dilation of an arterial wall/vein due to wall weakness
How does a true aneurysm differ from a false?
True = at least one arterial layer is unbroken. Most associated with atherosclerosis
False = usually caused by trauma + wall rupture - blood escapes to form a clot
What is a berry aneurysm?
An aneurysm within the cerebral blood system
Usually occurs where the cerebral arteries leave the circle of willis
More likely to rupture if posterior
Define a haemorrhage (in brain terms)
Abnormal escape of blood from an artery (subarachnoid, extradural, subdural)
Define a subarachnoid haemorrhage
Bleeding into the subarachnoid space (between Pia and arachnoid mater)
What are 5 symptoms of a subarachnoid haemorrhage?
Thunderclap headache!!!! (sudden onset, worst pain ever, occipital)
N&V
Reduced GCS/drowsy
Give 3 signs of a subarachnoid haemorrhage
Neck stiffness after 6 hours
Focal neurology @ presentation
Terson’s Syndrome if more severe
What is Terson’s syndrome
Increase in intraocular pressure due to intraocular haemorrhage
Subhyaloid haemorrhage
Vitreous haemorrhage
What are 5 non-modifiable risk factors for SAH?
FHx (3-5x risk)
Coagulopathy
Past Hx
Other medical conditions: Polycystic Kidney Disease, Ehlers Danlos
What are 3 modifiable risk factors for SAH?
Smoking
HTN
Alcohol Misuse
What are 2 investigations for SAH?
Urgent CT
Lumbar puncture (if CT is -ve but strong S&S)
What is important to remember about doing a lumbar puncture to investigate a SAH?
Have to wait 12hr after 1st presentation as RBCs need to break down
If yellow due to bilirubin = old blood from a SAH
What is the very initial management of a SAH?
A to E!!!!
Neurosurgery referral!!!!
HDU admissioN!!!
What is the conservative management of a SAH?
Regular reexamining of the CNS
Hydration to maintain BP and cerebral perfusion
What is the medical management of a SAH?
Treats actual condition - Nimodepine (Ca channel antagonist) to reduce vasospasm therefore maintaining cerebral perfusion
Treats symptoms - opiate analgesia + laxative, anti-emetic, NO NSAIDS OR ANTICOAGULANTS
What is the surgical management of a SAH?
Coil/clip the aneurysm
External ventricular drain
What are the causes of a SAH?
Trauma
Berry aneurysm e.g. at MCA bifurcation
What are the early complications of a. SAH?
Rebleeding
Hydrocephalus (ventricles block so CSF can’t drain)
Stroke
Hyponatraemia
What are the late complications of a SAH?
Seizures epilepsy
SIADH and hyponatraemia
Coil prolapse
Define a subdural haemorrhage
A collection of blood/bleeding into the subdural space (between dura and arachnoid mater)
What is the aetiology of a subdural haemorrhage?
Rupture of bridging veins as they cross from the subdural space into dural sinuses e.g. due to shearing forces from trauma
What are the symptoms of a subdural haemorrhage?
Fluctuating levels of consciousness
Pupillary changes
Headache
‘within the setting of head trauma’
What are the signs of a subdural haemorrhage?
Raised ICP
Seizures
What are the changes of a SDH seen on CT? (4)
Colour = Acute (<3 days) = bright, white blood. Chronic (>3 weeks) = black blood
Usually unilateral - fall cerebri prevents movement
Crescent shaped
+/- midline shift
What is the conservative and medical management of a subdural haemorrhage?
C - A to E
M - none really
What is the surgical management of a subdural haemorrhage?
Acute = Relieve ICP via immediate neurosurgery (do a craniotomy)
Can do burr holes for subacute or chronic
Define an extradural haemorrhage
Bleeding between the periosteal layer of the dura mater and the inner surface of the skull
What are the symptoms of an extradural haemorrhage?
LOS at time of initial injury
Lucid interval - transient recover +/- ongoing headache
Reduced consciousness, vomiting, seizures
Coma, CN palsies, pupillary changes
What is the aetiology of an extradural haemorrhage?
Secondary to trauma/fracture of temporal or parietal bone e.g. at pterion
Severs the middle meningeal artery
Or, can be venous if tearing of dural venous sinus
Can an extradural haemorrhage cross the midline?
Yes!
Can cross the sutures as the periosteal layer travels though the suture line
Size is still limited as dura is strongly adhered to the bone at certain points
What are the investigations for an extradural haemorrhage?
CT - acute = blood is white
Biconx/round
Well demarcated
+/- midline shift
What is the management of an extradural haemorrhage?
C - A to E
M -
S - urgent neurosurgery referral + craniotomy + clot removal + ligation of blleding
What are the acute and chronic complications of an extradural haemorrhage?
A = death + seizures
C = permanent brain damage, AV fistula, pseudo aneurysm, seizures
Define cerebral venous thrombosis
Occlusion of venous channels in the cranial cavity including IVT, DVT
What is the cause of a cerebral venous thrombosis
Thrombus in dural venous sinuses = prevention of venous return in sinuses
Increased deoxygenated blood in parenchyma
+ Increased CSG as also can’t drain through arachnoid granulations
What is the clinical presentation of a cerebral venous thrombosis?
Depends where it is:
Sagittal - headache, vomitign, seizures, papilloedema
Transverse - Headache -/+ mastoid pain, papilloedema
Sigmoid - cerebellar signs
Inferior petrosal - CN V and CN VI palsy
Cavernous - Eye signs - chemosis, proptosis, pain on movement
What are the modifiable risk factors for a cerebral venous thrombosis?
Hormones - COCP, pregnancy, steroids
Infection - mastoiditis, folliculitis
Malignancy
Trauma
Dehydration
What are the non-modifiable risk factors for a cerebral venous thrombosis?
Congenital mainly e.g. skull abnormality, connective tissue disorders, coagulopathy
What are the investigations for a cerebral venous thrombosis?
Digital subtraction angiography is gold standard but hard to do in practice
CT to exlude SAH or meningitis
What is the management of a CVT?
C = A to E
M = LMWH, ?thrombolyse
S = Thrombectomy - not if large
What are the acute complications of CVT?
Venous infarction +/- haemorrhage
Hydrocephalus
AV fistula
What are the Long term complications of CVT?
Dependency
Death
What is lateral medullary syndrome?
Infarct of the posterior inferior cerebellar artery (PICA)
Presentation
ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner’s
contralateral: limb sensory loss
Does a patient still need to be anti coagulated following a catheter ablation e.g. for AF
yes please continue to take medications
What is Weber’s syndrome and what are the clinical findings?
Infarction of the arteries supplying the midbrain
ipsilateral III palsy
contralateral weakness
