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Transient Ischaemic Attacks Assessment and Management

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					Transient Ischaemic Attacks

      Whom to Refer?
      What to Expect?

Assessment and Management
      Dr Sheela Shah MD FRCP
     Consultant Stroke Physician
       Barnet General Hospital
• Defining TIAs
• Diagnostic Biomarkers
• Differential Diagnosis
• Vascular Risk Triage
• Special Situations (Cardioembolism, Intracranial
  and Extracranial Stenosis, Dissections, Women,
  Migraine)
• Neuroimaging and Neurovascular Imaging
• Research
• BCFHT TIA Services
Rapid Access to Specialist Assessment,
  Treatment and Stroke Prevention

 •   Public Awareness Campaigns
 •   Interventions in Ambulance Practice
 •   Health Professional Education
 •   High Risk Triage
 •   Diagnosis and Treatment
 •   Risk Factor Management
           TIA Definition Revisited

• No longer based on the 24 hour time frame
• Usually no structural damage in ischaemia < 1 hour
• 50% of TIAs usually last for < ½ hour

• Transient neurovascular deficit < 1 hour
• No neuroradiological change: MRI-DWI /CT perfusion
• Absence of any Biological Markers of Neuronal Injury
        Stroke / TIA Mechanisms

•   Occlusion at perforator orifice
•   Artery to artery embolism
•   Concomitant low perfusion slows clot clearance
•   Branch artery occlusion with collaterals
•   Cardioembolism
    Specific Types of Cortical Ischaemia

•   Periventricular lesions = SVD / Lacunar
•   Subcortical lesions = Vasculitis / Amyloid
•   Borderzone lesions = Anterior / Posterior / Internal
•   Reversible Cerebral Vasoconstriction Syndrome
•   Reversible Posterior Leucoencephalopathy Syndrome
Borderzone Infarcts presenting as TIAs

•   12 % prevalence
•   Abrupt and progressive
•   Fluttering-Stuttering
•   10-20 % with Hypotension / LOC / Syncope
•   Motor / Sensory Hemiparesis or Aphasia
•   Neuropsychiatric disturbance (Internal BZI)
               Stroke Biomarkers
•   Brain Natriuretic Peptide
•   D-Dimer
•   Brain Specific Protein (after 24 hours)
•   MMP 9
•   Glial Fibrillary Acid Protein (after 2 hr in PICH)
Biomarkers as Predictors of Stroke
•   Multimarker Index of < 1.3 = “Mimic”
•   Haemorrhagic Transformation risk
•   Safety in Thrombolysis
•   Very high in Malignant MCA infarct

• 99.85% accuracy if Ischaemic Marker is
  present and Haemorrhagic Marker is absent
  (BSP / BNP are +ve & GFAP is –ve at onset)
           TIA and Stroke Mimics
•   Hypoglycaemia
•   Todds paralysis / Seizure
•   SOL
•   Acute SDH
•   Migraine
•   MS
•   Toxic Encephalopathy / Acute Delirium
•   Conversion reaction / Psychosis
Who? Indications for Evaluation

•   High Risk TIA / Minor Disability Stroke
•   7-day stroke risk ater TIA = 10%
•   Prevention of Heart Attacks
•   Prevention of Strokes
•   Prevention of Dementia
•   Confirmation of the diagnosis
•   Identification of site of lesion and its cause
•   Cryptogenic strokes in young patients
•   Familial and rarer cause (vasculitis, avm)
Cumulative Vascular Risk Triage
• ABCD 2 score > 4 / 7 = High Risk TIA
Age: 0 = < 60 years of age; 1 = > 60 years of age
BP: 0 = <140/90 mm; 1 = >140/90 mm or >140 mm Systolic or >90 mm Diastoli
Clinical features: 2 = Unilateral weakness Face, Arm, Leg or / and Loss of Vision
                   1= Speech disturbance without other signs
Duration of event: 0 = < 9 minutes; 1 = 10 to 59 minutes 2 = > 60 minutes
Diabetes: 0 = No Diabetes; 1 = Diabetes present, new diagnosis, treated

•   Unilateral weakness
•   Atrial Fibrillation
•   Large Artery Disease (Carotid / Ao Arch)
•   Framingham Risk Equation
•   Metabolic Syndrome
What ? Diagnosis-Investigations-Rx

 •   Neuroimaging
 •   Cardiac and Vascular Imaging
 •   Arrhythmia Assessment
 •   Syncope Testing
 •   Lipid and Glycaemic Screen
 •   General Life-style Factor Intervention
 •   Education: Secondary Prevention Targets
   Neuroimaging in TIA and Stroke
• NICE: MRI to confirm diagnosis or vascular
  territory (not CT)

• SIGN: MRI + DWI and GRE in late presenters
  > 1 week , mild deficits, small lesions and
  posterior fossa lesions

• Ischaemic lesions may take 3 hours to appear
  on MRI sometimes and CT is best for rTPA to
  exclude contraindications for thrombolysis
Multi-professional Roles in Preventing
Pre-hospital Delay to Rapid Access

 •   Media and Public Health Education
 •   Paramedic Education
 •   Stroke Assessment Tools (FAST/ROSIER)
 •   Triage to a Stroke Specialist Centre
 •   Pre-notification by Paramedics
 •   Partnership between LAS and Secondary care
     pathways to rapid access
How? Specific Measures / Interventions

 •   Neurovascular Evaluation
 •   Cardiovascular Evaluation
 •   Metabolic Syndrome Management
 •   Life-style influences
    Role of Neurovascular USG / CA Duplex

•   Isolated vascular risk factor
•   Reliable surrogate marker of silent atherosclerosis
•   Vulnerable plaque vs vulnerable population studies
•   Aortic arch atheroma
•   Plaque morphology and inflammation
•   MRA / Functional Plaque Imaging
               Carotid Plaque Imaging
    Plaque stages: I (Foam); II (Fat); III (Pre-atheroma);
    IV (Atheroma); V Fibroatheroma; VI (surface defect and
    haemorrhage); VII (calcified) and VIII (Fibrotic)


•   Unstable plaque surgery causes more DWI lesions
•   Unstable plaques have high risk : Best Medical Rx
•   High echogenicity / low heterogeneity = stability
•   Surgery before stage VII and VIII (ideally at IV - VI)
    Symptomatic Carotid Arterial Stenosis
•   Duplex within 24 hours
•   CEA surgery within 24 hours (High Risk)
•   Ideally within 7 days of index event (Low Risk)
•   Ideally for age < 70 years
•   Stenosis of > 50 to 99% by NASCET (men)
•   Women have lower risk (>70 to 99%)
•   Carotid End-Arterectomy vs. Stents (less favoured)
      Asymptomatic CA Stenosis
•   Men
•   Age < 70
•   Bilateral disease
•   High grade caritod stenosis
•   No ipsilateral event for atleast 6 months
       Intracranial Large Arterial
      Atherosclerosis and Stenosis
•   Most common cause of ischaemic strokes
•   15% annual stroke recurrence
•   Progressive over time
•   Multifocal disease
•   Intensive medical therapy
•   Antithrombotic therapy
•   Angioplasty
•   Stenting
           Intracranial Stenosis
•   Aggressive and highly recurrent
•   Atherosclerosis of intracranial vessel
•   Blocked by cardiac embolus or
•   Blocked by microemboli from CA stenosis
•   Association with borderzone infarction
•   Association with syncope
•   Haemodynamic and thromboembolic interplay
•   Aspirin+ Statin + Warfarin + Exercise
TIA and Cardioembolism
•   CHADS score for OAC
•   Dilated LA / ILD recorder
•   Multiple asymptomatic cortical infarcts on MRI
•   PFOs and cryptogenic strokes
•   PFO with Aneurysmal IAS / Thrombus
•   ASD
•   Watershed Lesions requiring PPM + OAC
       TIA due to Vascular Dissection

•   Carotid vs Vertebrobasilar
•   Subintimal vs Subadventitial
•   Intradural (VA and BA) vs Extracranial (CA)
•   OAC or Antiplatelet Therapy
•   Treat with rTPA -/+ Endovascular repair
•   Duration of treatment and follow up imaging
Cervical and Cerebral Arterial Dissections

• 20 % stroke in young adults
• 1/3 complain of local pain
• Intramural hematoma: stenosis
                            occlusion
                            compression / SOL
                            rupture (ICH/SAH)
• Best diagnosis MRI with FatSat Ti and MRA
• Bed Rest for Intracranial lesions
• Intracranial lesions: ischaemia and haemorrhage
TIA and Migraine
•   Oral Contraceptives
•   Premenstrual syndrome
•   16 fold stroke risk during pregnancy/preeclampsia
•   Migraineurs with aura have multiple vascular risks
•   Endothelial and arterial dysfunction
•   Prophylactic Aspirin
•   Life-style advice
           TIA in Women

•   Aspirin in primary prevention
•   Risk in Carotid Surgery
•   Thrombolysis more effective
•   Post-partum and Pre-eclampsia
•   HRT risk of cerebral infarction
Research in Secondary Stroke Prevention

• BP target = < 120/80 mm Hg
• ACE-inh or AR 2 B = ACE-inh + AR 2 B
• Intensive Glycaemic Control ? Bad /? Good
• CEA for Asymptomatic CAD = no benefit and NNT
  100 if complication rate is < 3%
• AF stroke risk = X 5. Warf Rx= INR > 2 < 3.5
• AF and ASA + Clop (NNT= 28 and NICH=20)
Metabolic Syndrome
•   BMI > 30
•   Abdominal obesity: 102 cm (M), 88 cm (F)
•   Hypertension
•   Hyperglycaemia
•   Insulin Resistance
•   Atherogenic Dyslipidaemia >>Trig + << HDL
•   Albumin/ Creatinine Ratio (urine) > 30
           Statins and Stroke
•   LDL < 2
•   Total Cholesterol < 3.5
•   HDl > 1.03 (m) and 1.3 (f)
•   SPARCL : 80 mg Atorva and ICH
•   Rosuva superior to Placebo; NNT = 120
•   Simva first line
Recent Advances (Trials and Research)
• Dronedarone anti-arrhythmic cardioversion in
  Atrial Fibrillation

• Cilostazole Phosphodiesterase Inhibitor in
  place of Aspirin

• Terutoban Thrombin Inhibitor for AF (safer
  than Ximelagatran) (PERFORM)
    Barnet and Chase Farm Hospital
    Rapid Access Referral Process

•   Targeting GP practices
•   Distribution of referral forms
•   Daily specialist-run clinics 5/7
•   Weekend arrangements
•   Neuroradiology + Neurovascular Liaison
•   Education and Audit
• Patient Education and Empowerment
Success by the drivers for change
•   2006 = 280 referrals seen within 5 days
•   2008 = 360 referrals seen within 3 days
•   2009 > 62% high risks seen/Rx in 24 hrs
•   2009 > 80% low risks see/Rx within 7
•   2009/10/11 = 7/7 access to out-patient care
•   ………………..= 100% outcomes
•   ………………..= participation in research