Stroke

A stroke is a clinical syndrome of rapid onset neurological symptoms (usually focal), lasting more than 24 hours (or leading to death), with a vascular cause.

A TIA is identical but symptoms will completely resolve within 24 hours.

Background and Epidemiology

  • Around 150000 strokes occur in the UK every year with an incidence of around 170/100,000 population
    • Higher in men than women
    • Fourth leading cause of death in the UK
      • 1 in 5 strokes are fatal
  • A stroke is a medical emergency – and urgent treatment can be crucial to a better prognosis. (TIME IS BRAIN)

Risk Factors

  • Non modifiable risk factors
    • Age
    • Previous stroke
      • 5-14% in 1st year; 24-42% in 5 years
    • Family history
    • Race- afro-Caribbean individuals twice as likely
  • Modifiable
    • Hypertension- most significant risk factor as it is directly involved in multiple pathophysiological aetiologies associated with stroke
    • Diabetes- aside from cardiovascular complications associated with DM, poor glycaemic control is also a controllable risk factor
    • Smoking
    • Hypercholesterolaemia
    • Poor diet, exercise etc and obesity
    • Carotid artery disease and atrial fibrillation

Aetiological Classification of stroke

  • It is crucial to classify a stroke as to whether it is ischaemic (85%) or haemorrhagic (different management)
  • From ischaemic stroke it is then useful to further classify by aetiology (TOAST or ASCO classifications)
    • Large vessel disease (arterial atherosclerosis- embolus/thrombosis- 40%)
      • This can either originate from within the carotid artery(s) or distally, closer to the brain.  Usually occurs at bifurcations.
      • Ask about hypertension, coronary heart disease, diabetes
    • Small vessel disease (usually arteriosclerosis but can be microatheroma)
    • Cardioembolic disease (most commonly seen in atrial fibrillation; but also seen in infective endocarditis)
    • Other causes
      • Rarer causes such as severe hypotension (watershed infarction); vasculitides; arteriovenous malformations; amyloidosis; etc
    • Unknown cause

Presentation

  • Symptoms, by definition, are acute onset
    • Facial; arm or leg weakness
    • Speech impairment
    • Visual impairment
  • The patient may also have upper motor neuron signs e.g. spasticity, brisk reflexes
    • NB These usually develop later.  Initially, atonia/areflexia may be present.
  • In the acute setting, the rosier scale may be used to help differentiate strokes/TIA from stroke mimics

Anatomical Classification of stroke (Bamford)

  • Total Anterior Circulation Syndrome (TACS)
    • Patients present with ALL of these signs/symptoms
      1. Hemiplegia of at least two of arm, leg or face with or without sensory loss
      2. Homonymous hemianopia
      3. Cortical signs e.g. dysphasia is classical, neglect, visual problems etc
    • TACS is caused by a proximal occlusion to the middle cerebral artery, and is the most severe kind of stroke and, on CT, can affect almost all of one lobe.  5% of patients are alive and independent at 1 year.
  • Partial Anterior Circulation Syndrome (PACS)
    • Patients can present with either
      • 2 out of 3 features of TACS
      • Isolated cortical features
      • Monoparesis or loss of proprioception in one limb
    • PACS is much less severe and 55% of patients are alive and fully independent at 1 year.
  • Lacunar syndrome (LACS)
    • Caused by small vessel disease infarcts of the deep brain (basal ganglia, thalamus, white matter tracts, brain stem) caused by occlusion of a single deep penetrating artery (usually of the middle cerebral).  It commonly presents with
      • Pure motor hemiparesis
      • Pure hemisensory loss
      • The above together
      • Ataxic hemiparesis
    • LACS has the best prognosis
  • Posterior Circulation Syndrome (POCS)
    • Can cause an array of signs/symptoms
      • Cranial nerve palsies
      • Bilateral motor/sensory deficits
      • conjugate eye movement disorders (problems with fixation and tracking)
      • Isolated homonymous hemianopia
      • Cortical blindness
      • Cerebellar deficits without ipsilateral motor/sensory signs

Investigations

  • Blood tests
    • FBC- thrombocytopenia, anaemia
    • Glucose
    • Lipids
  • ECG
  • CT head
    • NB This will be normal within the first few hours of an ischaemic stroke
      • This is an indication for thrombolysis (not a contraindication)
        • changes on CT (ischaemic changes) will often occur after the window for thrombolysis
    • What CT is particularly useful for is differentiating haemorrhagic and ischaemic stroke (this is crucial for management, and ideally should be done before initiation of any management)
  • MRI is the imaging modality of choice later (i.e. days later).  Due to the duration of the scan and availability, combined with patient condition, it is rarely used in the hyperacute setting.
  • Remember to measure blood pressure and other vital signs.
  • Carotid doppler USS is useful for identifying potentially treatable large vessel (carotid) disease.

Management

  • Thrombolysis
    • Tayside have their own protocol which are based on SIGN guidelines
    • Patients admitted within 4.5 hours of definite symptom onset, who fit the inclusion/exclusion criteria, should be treated with recombinant tissue plasminogen activator (alteplase- dose adjusted to weight)
      • Treat as soon as possible
    • Contraindications
    • Untitled picture
  • Aspirin/clopidogrel 300mg should also be given to all patients with ischaemic stroke/TIA (for at least 14 days)
    • Avoid for 24 hours after thrombolysis treatment
    • In patients who have suffered a TIA- use the ABCD2 score
      • Age >=60 (1)
      • BP >=140/90 (1)
      • Clinical features
        • Unilateral weakness (2)
        • Speech disturbance, no weakness (1)
      • Duration of symptoms
        • >60 mins (2)
        • 10-59 mins (1)
      • Diabetes (1)
    • A score >=4 should be treated as stroke i.e. 300mg aspirin stat followed by 75mg daily and assessment within 24 hours; with secondary prevention following the event.
      • A score of <4 should be also be given 300mg stat dose of antiplatelet and 75mg daily but can be seen within a week
  • Other points to consider- RCP recommend monitoring
    • blood glucose (>4 <11); hydration; O2 sats; temperature
      • BP should not be lowered in the acute setting unless there are complications
  • Anticoagulation is not routinely recommended
    • Even in patients with newly identified AF- warfarin treatment should start 14 days after a major stroke (earlier for minor strokes- i.e. ones that resolve within a week)

Secondary Prevention

  • Low dose clopidogrel (75mg daily), (aspirin 75mg + dipyridamole (200mg MR BD) as an alternative) should be prescribed after ischaemic stroke/TIA
  • A statin (e.g. atorvastatin) should be prescribed to all patients with ischaemic stroke, regardless of cholesterol level
  • Patients in AF should be started on warfarin (target INR 2-3)
  • All patients (haemorrhagic or ischaemic) should be considered for treatment with an ACE inhibitor and thiazide diuretic, regardless of blood pressure, unless there are contraindications
    • If blood pressure is still high, manage as best possible.
  • Carotid Endarterectomy
    • Can be offered to patients (ideally within 14 days) with severe (>70% defined by USS NASCET criteria or >50% as defined by ECST criteria) carotid stenosis and is symptomatic on the corresponding side (i.e. a left coronary artery stenosis in a patient with right sided weakness)
    • If the patient has significant stenosis in the contralateral carotid vessel, consider also repeating the procedure on this side also.  (Likewise, if this is an incidental finding, surgery should be considered
    • Complete carotid occlusion is a relative contraindication (the patient will already be compensating with collateral circulation via circle of willis)
      • Complete occlusion of the contralateral side is also a relative contraindication (recently shown little risk of adverse events)- alternatively a stent may be necessary

The role of rehabilitation and management of residual symptoms

  • Patients should be mobilised as early as possible, with early input from physiotherapy and occupational therapy
  • Speech and language therapy are also often required to assess and manage swallow and dysarthria but also in the management of dysphasia caused by stroke
  • Also make sure that nutrition and diet is adequate and refer to a specialist if necessary
  • Management of spasticity may be a problem
    • Botox injections may be of use
  • Other problems include continence issues (may be managed pharmacologically or conservatively, depending on the patient’s functional status); pain; mood disturbance (may require treatment with antidepressants); pressure ulcers etc

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