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GP Lecture Programme 3 February 2010. Dr Stephen Louw Stroke Physician RVI Newcastle upon Tyne. Population Relative Risk for Stroke. High ABCD2 score: 8% chance in next 2 days AF 5 – 17x (if >2 risk factors, 18% stroke p.y.) Hypertension 3-4 Alcohol 4 Migraine: 2.16 IHD 2-4 CCF 2-4
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GP Lecture Programme3 February 2010 Dr Stephen Louw Stroke Physician RVI Newcastle upon Tyne
Population Relative Risk for Stroke • High ABCD2 score: 8% chance in next 2 days • AF 5 – 17x (if >2 risk factors, 18% stroke p.y.) • Hypertension 3-4 • Alcohol 4 • Migraine: 2.16 • IHD 2-4 • CCF 2-4 • Diabetes 2-4 • Smoking 1.5-2.9 • Hyperlipidaemia – uncertain as a sole risk • PFO 26% of general population have a PFO.
Commonest TIAs Middle Cerebral Artery Territory • Total or partial anterior Circulation TIA • Hemiplegia/hemianaeasthesia • Homonymous hemi-anopia • Cortical problem: dysphasia/visual or sensory neglect • Lacunar-type: pure motor or sensory or mixed • Amaurosis fugax • Post circulation (difficult to diagnose)
Middle Cerebral Artery TerritoryThe focus of ABCD2 scaleValidation and refinement of scores to predict very early stroke risk after TIA: Johnston SC, Rothwell PM et al. Lancet 2007. Jan. 27:369:283-92.
Middle Cerebral Artery TerritoryThe focus of ABCD2 scale The focus of investigations in hospital: • Identify patients with critical internal carotid artery stenosis • Rapid referral for carotid endarterectomy • CEA • Benefits: reduces stroke risk by 50% • Risks: immediate death or stroke: 2 – 3%
Carotid EndarterectomyEuropean Carotid Surgery Trialists’ Collaboration Group (ECTST) The Lancet 1998;351:1379-87 CLASSIC PAPER • Patients with recent TIA or stroke and 70 – 99% carotid stenosis clearly benefit in terms of stroke prevention. Confirmed NASCET (1991) • Pts with <70% stenosis were harmed by CEA. • NNT (surgery) 14 pts to prevent a major ipsilateral carotid territory stroke over the next 5 years.
Limb shaking TIA • 1-2 min duration • Usually severe carotid stenosis • Often good surgical candidates • Differential diagnosis • Partial seizure • Tremor
Capsular warning TIAGeoffrey Donnan (Australia) Neurology 1993;43:957 • 4.5% of TIAs • Ischemia due to haemodynamic phenomena in a diseased, single, small penetrating vessel • Leads to lacunar infarct and involved a single penetratingvessel
Posterior Circulation TIA POCS TIA is more likely if: ·true diplopia ·DDK ·past pointing ·Dysarthria
Posterior Circulation TIA Low predictive rate for POCS TIA if: Isolated features of • ‘Dizziness’, • unsteadiness, • vertigo or • ‘ataxia’.
Transient Global Amnesia • Sudden onset of disorientation • amnesia for immediate events • Speech intact • No other focal neurology • Resolves within minutes
Ocular migraine Transient loss of vision Usually with headache Basilar type migraine Affects both sides Rarely motor signs Aura may include: Blindness Vertigo Diplopia Dysarthria Ataxia Unusual types of Migraine
Rapid recognition of symptoms and diagnosis • Use the FAST tool to screen for stroke or TIA outside hospital Reproduced with permission from The Stroke Association
How accurate is FAST?Diagnostic Accuracy of Stroke Referrals…J Harbison, O Hossain, D Jenkinson, J Davis, SJ Louw, GA Ford.Stroke 2003;34:71-76 • 487 patients; 356 stroke/TIA • FAST used by ambulance paramedics • 23% = non-stroke • 46% admitted within 3 hours • Primary Care Doctors • 29% = non-stroke • 14% admitted within 3 hours • ER • 29% = non-stroke
Limitations of FAST • Does not take pre-existing disability into account • Low sensitivity for posterior circulation strokes: • occipital lobes (vision) • cerebellum (often no weakness) • brain stem (sensory deficit, cranial nerve lesions)
TIME IS BRAINTime window: stroke to needle 4.5 hrs Suspected stroke? Within 3.5 hours? Call 999: blue light patient into stroke unit
Time-windows for thrombolysis • A limit (not a ‘target’) • Anterior circulation strokes • 4.5 hours
Reason for time-limit • For every 3 patients we thrombolyse, one will have a significantly less marked level of impairment. but….. • One in 30 patients we thrombolyse, will be harmed (including death) due to symptomatic bleeding (including intracranial).
PH 2 r-TPA in Newcastle upon Tyne • In total 4 major bleeds – 2 deaths
Time-windows for thrombolysis • A limit (not a ‘target’) • Anterior circulation strokes • 4.5 hours • Anterior circulation strokes in very young people • 6 hours (intra-arterial thrombolysis)
Time-windows for thrombolysis • A limit (not a ‘target’) • Anterior circulation strokes • 4.5 hours • Anterior circulation strokes in very young people • 6 hours (intra-arterial thrombolysis) • Posterior circulation strokes • 12 hours (intra-arterial thrombolysis)
Fast track system: Newcastle • All cases blue lighted by ambulance to Acute Medical Unit (AMU) • Ambulance paramedics notify before setting off from patient’s home • AMU SpR/Senior Nurse phones Stroke Consultant and Notifies CT scan personnel
Cases NOT for 999 referral • Low likelihood of benefit from rTPA • poor pre-stroke functional level • dementia, Nursing Home • uncertain onset time (e.g. “woke up with stroke”) • seizure • High risk of bleeding complix from rTPA • surgery/major trauma within the last 2 weeks • on warfarin, bleeding tendency
Common Stroke Mimics • Seizure – Todd’s paralysis • Cardiovascular collapse • Migraine • Labyrinthine disorders • Infection- related delirium (“?dysphasia with no other focal neurological deficit”)
Improving stroke services in the North East • Primary prevention • FATS 5 guidelines • Anticoagulation for AF • Hypertension • Secondary prevention: Spotting TIAs • Rapid referral of acute stroke • Enhanced rehabilitation services