stroke

pathways for clinical learning

Stroke

Mark Hall

Clinical Teaching Fellow


Objectives• Revise definitions of stroke and TIA

• Discuss how a patient with a stroke presents and stroke mimics

• Elicit a relevant history from a patient with suspected stroke

• Examine a patient with suspected stroke

• Revise initial investigation and treatment of a patient with suspected stroke


What is a stroke?“…a clinical syndrome consisting of rapidly

developing clinical signs of focal (or global in case of coma) disturbance of cerebral function lasting more than 24 hours or leading to death with no apparent cause other than a vascular origin.”

Hatano S. Experience from a multicentre stroke register: a preliminary report. Bulletin of the World Health Organisation 1976;54(5):541–553.


What is a TIA?“A transient ischaemic attack (TIA) is

defined as stroke symptoms and signs that resolve within 24 hours.”

Hatano S. Experience from a multicentre stroke register: a preliminary report. Bulletin of the World Health Organisation 1976;54(5):541–553.

The National Collaborating Centre for Chronic Conditions National clinical guideline for diagnosis and initial management of acute stroke andtransient ischaemic attack (TIA). Royal College of Physicians London 2008


Stroke• Stroke is the third commonest cause of

death and the most frequent cause of severe adult disability in Scotland

• High mortality (10 - 20% at 30 days)

• 50% of survivors are dependent

• 10% will have a recurrence within 1 year


Stroke - Causes• Causes of stroke

– Ischaemic (80 %)• Embolic (AF, embolus from metallic valve, carotid artery

plaque)• Atherosclerotic• Prothrombotic state

– Haemorrhagic (10-20 %)• Hypertension• Cerebral artery aneurysm• Over-anticoagulation• Bleeding diathesis


Stroke – Risk Factors• Risk factors

– Age– Smoking– Family history– Hypertension– Diabetes– Hyperlipidaemia– AF, prothrombotic state


The Brain


How might a person with a stroke present?


How might a person with a stroke present?

• Arm weakness• Leg weakness• Facial Droop• Slurred speech• Unable to get the right words out• Uncomprehending• Falls• Fractures


History(who gives the history?)

• Onset

• Symptoms

• Time course

• Risk factors

• Past Medical History

• Medications


Examination

• Pronator drift

• Tone

• Power

• Reflexes

• Coordination

•Cranial Nerves

•Gait

•Visual Fields

•Speech

•Comprehension

•Swallow


Which Pattern?Upper Motor Neuron• Muscle weakness• Increased Tone• Increased Reflexes• Up going plantar -

Babinski

Lower Motor Neuron• Muscle weakness• Fasciculations• Decreased tone• Decreased reflexes• Absent Babinski


Clinical assessment• Hemianopias


• Expressive dysphasia– ‘telegraphic speech’

• Receptive dysphasia– Fluent meaningless speech– Neologisms


Classification of Stroke• TACS (Total anterior circulation stroke)

– A combination of:• New higher cerebral dysfunction (eg: dysphasia)• Homonymous visual field defect• Motor and / or sensory deficit of (at least 2 of) face / arm / leg

• PACS (partial anterior circulation stroke)– 2 or 3 of TACS– OR New higher cerebral dysfunction alone (eg: dysphasia)– OR motor or sensory deficit more restricted than for LACS

• LACS (Lacunar anterior circulation stroke)– Pure motor

• Unilateral weakness (2 or 3 of face / arm / leg)– Pure sensory

• Unilateral sensory disturbance (2 or 3 of face / arm / leg)– Sensory motor (combination of above)– Ataxic hemiparesis

• Hemiparesis with ipselateral cerebellar ataxia

• POCS (posterior circulation stroke)– Cerebellar dysfunction– Brainstem signs– Occipital lobe dysfunction– Bilateral weakness / sensory dysfunction– Ipselateral CN palsy with contralateral weakness (crossed signs)


Investigations


Investigations• Bloods

• ECG

• CXR

• CT Brain

• (echocardiogram)

• (carotid doppler)


Current guidance - evaluation• NIHSS (National Institute of Health Stroke Scale)

– To evaluate neurological status / predict severity of Stroke– Complete hemiparesis with dysphasia, dysarthria, hemianopia

and sensory loss scores 25+ (often cut off point for thrombolysis)


Current guidance – Acute Stroke Care

• NICE pathway - Acute stroke• SIGN guidance 108

• Perform brain imaging (CT scan) immediately if:– Indications for thrombolysis– Possible haemorrhage / RICP

• On anticoagulant treatment• Known bleeding tendency• Reduced consciousness (GCS <13)• Unexplained progressive or fluctuating symptoms• Papilloedema, neck stiffness or fever• Severe headache at onset of stroke symptoms• Brainstem or cerebellar stroke

• Otherwise imaging ASAP (within 24 hours)


Current guidance – Acute Stroke Care

• Criteria for thrombolysis – No sign of haemorrhage on immediate brain

imaging– Definite onset within 4.5 hours– No contraindications

• These may be relative depending on clinical picture – discuss with stroke team on call

• Acute stroke unit admission


Contraindications to thrombolysis• Bleeding

– Known history of or suspected intracranial haemorrhage

– Anticoagulants (except warfarin if INR<1.4)

– Treated with LMW Heparin within last 48 hours & APTT is still raised

– Platelet count of below 100,000/mm3– Known haemorrhagic diathesis

– Severe liver disease

– GI / Menstrual / urinary bleeding during the last 21 days

– Major surgery or significant trauma in last 14 day

• Physical status– Seizure at onset of stroke– BP > 185 mmHg systolic (or diastolic > 110 mmHg) – BM < 2.8 or > 22 mmol/l – Bacterial Endocarditis / Pericarditis

– Symptoms rapidly improving before thrombolysis– NIH Stroke Scale <5 (very minor neurological deficit) or > 25 (very severe)

• Other– Head injury within the last 3/12

– Other stroke within last 3/12

– History of stroke PLUS diabetes


Stroke mimics• Seizure

• Hypoglycaemia

• Electrolyte disturbance (Na+, Ca++)

• Subdural haematoma

• Brain tumour

• Lower Motor Neurone Lesion


Treatment-ischaemic/embolic• Consider thrombolysis

• Aspirin 300mg od for 2 weeks then clopidogrel 75mg od

• Statin

• Surgery?


Treatment-haemorrhagic• Reverse anticoagulation

• Surgery is rarely needed

• Usually for hydrocephalus

• Monitor for neurological deterioration

• Re-image


Complications of stroke • Pressure sores• Pneumonia (including aspiration)• DVT / PE• UTI• Incontinence• Depression• Seizures• Fatigue• Spasticity / contractures• Shoulder pain• Impact on relationships / driving / work /

independence


Transient Ischaemic Attack• TIA

– Sudden onset neurological dysfunction lasting < 24 hours

– Often lasts for minutes

– No lasting structural neurological damage – Aetiology as for stroke– May predict future stroke

• Scoring scales for likelihood• Secondary prevention


TIA – risk stratification• ABCD2 algorithm predicts very early risk of stroke following a TIA

– A – Age • >60 =1

– B – Blood pressure • >140/90 mmHg = 1

– C – Clinical features of the TIA• Unilateral weakness = 2 • Speech disturbance without weakness = 1

– D1 – Duration of symptoms• > 60 min = 2 • 10-59 min = 1 • <10 min = 0

– D2 – Diabetes • Diagnosed with diabetes = 1

• The corresponding 2 day risks for a subsequent stroke are– ABCD2 scores

• 0-3 = 1% (low risk, Start Aspirin 300mg OD and refer to TIA clinic)• 4-5 = 4% (High risk, consider admission. Aspirin 300mg OD, urgent TIA

clinic)• 6-7 = 8% (As above)

Johnston SC et al (2007) Lancet, 369, 283-292


TIA - management• Start Aspirin 300mg OD• Depending on ABCD2

– Admit to hospital – Refer to TIA clinic (within 24 hours or 1 week)

• Secondary prevention as per stroke• Consider Anticoagulation if in AF

– Based on CHADS2VASC score• Calculates stroke risk for patients with AF


AF – risk stratification• CHADS2 VASc Score

– Congestive Cardiac Failure = 1 – Hypertension = 1 – Age 65-74 years = 1– Age > 75 years = 2 – Diabetes = 1 – Stroke / TIA history = 2 – Vascular Disease (PVD or IHD) = 1 – Sex (Female) = 1 – Maximum Score 9 points

• 0 = Low risk, no need to anticoagulant• 1 = Low – Moderate risk, consider oral anticoagulation or Aspirin• 2 = High risk, consider oral anticoagulation


Summary• Act FAST

• Think of thrombolysis early

• Focus on onset (sudden/stuttering)

• Ask about progress

• Ask yourself– Have they had a stroke?– If they have had a stroke, why?

• Examine carefully – look for patterns


Summary• Remember to assess swallow and act

accordingly• Communication is vital – take time to do it well• Haemorrhage

– reverse anticoagulation– think about hydrocephalus

• Infarct– Aspirin 300mg od for 2 weeks then clopidogrel

75mg od


Further Reading• Hacke, W., Kaste, M., Bluhmki, E., Brozman, M., Dávalos, A., Guidetti, D., Larrue,

V., Lees, K., Medeghri, Z., Machnig, T., Schneider, D., von Kummer, R., Wahlgren, N., Toni, D. and the ECASS Investigators (2008) Thrombolysis with Alteplase 3 to 4.5 Hours after Acute Ischemic Stroke. The New England Journal of Medicine,359(13), 1317-1329.

• SIGN guideline 118 http://www.sign.ac.uk/pdf/sign118.pdf• SIGN guideline 108 http://www.sign.ac.uk/pdf/sign108.pdf