Transient Ischemic Attack

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Contents 1 More Specific Terms 2 Introduction 3 Etiology 4 Pathology 5 History 6 Clinical-manifestations 7 Laboratory 8 Diagnostic-procedures 9 Radiology 10 Complications 11 Differential-diagnosis 12 Management 13 More General Terms 14 Additional Terms 15 References

More Specific Terms

• transient monocular blindness (TMB); amaurosis fugax

Introduction

• A transient ischemic attack (TIA) is a focal neurologic deficit that resolves fully within 24 hours. The risk of subsequent stroke is 5-10%/year & is highest in the 1st month following a TIA. Liken to unstable angina of the brain. [17]

Etiology

• large vessel, low flow

• carotid stenosis
• intracranial stenosis

• embolic

• cardiac
• aortic arch atheroma
• intravenous drug abuse ( IVDA)

• lacunar or small penetrating vessel
• hematologic disorders

• hypercoagulable state
• thrombocytosis
• leukemia
• polycythemia
• sickle cell disease

• vasculopathies

• vasculitis (e.g. Takayasu's arteritis)
• arterial dissection
• fibromuscular dysplasia
• moyamoya

Pathology

• Any obstructive process in extra- or intracranial arteries can cause a low-flow TIA if collateral circulation to the ischemic area is also impaired. Lacunar TIA's are due to transient cerebral ischemia from stenosis of intracerebral penetrating vessels, usually from lipohyalinosis secondary to hypertension or atheromatous disease at their origin.

History

• onset, improvement or progression of symptoms, anatomic location of deficit, activity prior to onset, headache, nausea/vomiting, loss of consciousness, brisk neck movement, visual aura, scotoma, vertigo, seizure, trauma, confusion, dysarthria, incontinence, dysphagia, palpitations, prior TIAs or strokes, amaurosis fugax, HTN, diabetes, CAD, hyper- lipidemia, IVDA, cocaine, valvular heart disease, migraine, anticoagulants, oral contraceptives, tobacco, alcohol

Clinical-manifestations

• general

• most TIAs last 10-20 minutes
• most patients with TIAs are neurologically intact
• low flow TIA's are brief ( minutes to hours), recurrent, & stereotyped.
• embolic TIA's are characterized by focal neurologic symptoms lasting hours

• carotid artery territory TIAs

• paresthesias of hand, arm & face ( contralateral)
• weakness of hand, arm & face ( contralateral)
• aphasia (dominant hemisphere)
• dysarthria
• unilateral neglect
• loss of vision ( ipsilateral eye)
• carotid bruit

• lacunar TIAs

• hemibody sensory loss or paresthesias
• pure motor hemiparesis

• vertebrobasilar artery territory TIAs

• dysarthria
• dysphagia
• vertigo
• ataxia
• diplopia
• visual field loss - homonymous hemianopia
• perioral paresthesias
• acute confusional state
• profound general weakness

Laboratory

• complete blood count ( CBC)
• coagulation studies

• PT/PTT, INR
• studies for hypercoagulable state

• serum chemistries:

• serum electrolytes
• serum glucose
• serum Ca+2

• erythrocyte sedimentation rate (ESR) or serum C-reactive protein ( serum CRP)
• antinuclear antibodies ( ANA)
• syphilis serology
• toxicology screen
• lumbar puncture

Diagnostic-procedures

• Holter monitoring
• angiography

• candidates for carotid endarterectomy
• long-term anticoagulation considered for patient with probable large vessel disease
• recurrent TIAs & inconclusive noninvasive evaluation
• suspected carotid or cerebral dissection

Radiology

• magnetic resonance imaging ( MRI) of the head a diffusion-weighted imaging may be more sensitive

• identification of vascular occlusions predicts further ischemic events [14]

• computed tomography ( CT) of the head if MRI not available
• carotid ultrasound ( Doppler)
• transcranial Doppler of intracranial vertebrobasilar system
• magnetic resonance angiography
• echocardiography
• combination of imaging + ABCD2 score ( ABCD3-I) refines prediction of stroke [19]

Complications

• risk of stroke substantial

• 2-33% within 24 hours depending upon ABCD2 score [18]
• 17-18% at 3 months [7]
• see risk factors for stroke after TIA [6]

• depression common (14% at 1 year) [22]
• anxiety may occur

Differential-diagnosis

• migraine headache
• seizures

• focal seizures may produce localized or migratory symptoms
• postictal weakness ( Todd's paralysis)

• brain lesions

• tumor
• subdural hematoma
• arteriovenous malformation
• multiple sclerosis

• metabolic disorder

• hypoglycemia
• hypercalcemia
• hyperventilation
• periodic paralysis

• peripheral nerve disorder

• carpal tunnel syndrome
• radiculopathy

• syncope
• myasthenia gravis
• vertigo

• labyrinthitis
• Meniere's disease
• benign positional vertigo

• thoracic outlet syndrome
• transient global amnesia

Management

• treat acute TIA as suspected stroke; hospitalize (see ACLS algorithm for suspected stroke)
• urgent assessment & treatment of patients with TIA or minor stroke diminishes subsequent hospital bed-days, acute costs, & 6-month disability [17]
• do not attempt to acutely lower blood pressure unless

• systolic blood pressure > 220 mm Hg
• mean arterial blood pressure > 140 mm Hg
• patient has acute coronary syndrome
• aortic dissection suspected

• thrombolytic therapy planned [4]
• lower blood glucose to < 150 mg/dL
• treatment depends upon underlying pathology
• carotid disease

• aspirin* 325 mg QD or Plavix ( clopidogrel) 75 mg PO QD
• statin or niacin if LDL > 100 mg/dL

• atorvastatin may reduce risk of stroke in high-risk patients [20]

• carotid endarterectomy (70-99% stenosis)
• hydration
• prevention of orthostatic hypotension

• vertebrobasilar disease

• aspirin, Plavix or Aggrenox
• heparin followed by warfarin

• lacunar TIA - aspirin* 325 mg QD, Plavix or Aggrenox
• cardiac emboli:

• heparin followed by warfarin
• patient with prosthetic valves:

• add dipyridamole or aspirin

• arterial dissection

• heparin followed by warfarin for 3-6 months
• follow with aspirin

• recurrent symptoms on aspirin

• increase aspirin* to 325 mg BID/ TID
• Plavix ( clopidogrel) 75 mg PO QD [16]

• combination therapies

• Plavix 75 mg + aspirin 81 mg QD

• NOT superior to clopidogrel alone [11] (see MATCH study)

• Aggrenox ( dipyridamole + aspirin), see ESPIRIT study

• ACE inhibitor + diuretic may be of some value [5]
• treat dyslipidemia with statin [16] or niacin

• aggressive statin therapy (i.e. high-dose atorvastatin) recommended for secondary stroke prevention [21]

• * may be no benefit to doses > 162 mg/day
• Follow-up:

• workup for coronary artery disease

• lipid panel
• rule out hyperhomocysteinemia
• ECG stress testing

• young patients with negative initial evaluation have better prognosis
• 10 year mortality 34% [13]

More General Terms

• cerebral ischemia

Additional Terms

• ACLS algorithm for suspected stroke
• intracranial arterial stenosis
• ischemic stroke
• reversible ischemic neurologic deficit (RIND)
• risk factors for ischemic stroke after TIA
• stroke; cerebrovascular accident (CVA)

References

1. Harrison's Principles of Internal Medicine, 13th ed. Companion Handbook, Isselbacher et al (eds), McGraw-Hill Inc. NY, 1995, pg 703
2. Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 537-540
3. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 1021-22
4. Medical Knowledge Self Assessment Program (MKSAP) 14, 15, American College of Physicians, Philadelphia 2006, 2009
5. Prescriber's Letter 8(7):38 2001
6. Journal Watch 24(7):54, 2004 Inatomi Y et al DWI abnormalities and clinical characteristics in TIA patients. Neurology 62:376, 2004 PMID: [1]
   - Warach S & Kidwell CS The redefinition of TIA: the uses and limitations of DWI in acute ischemic cerebrovascular syndromes. Neurology 62:359, 2003 PMID: [2]
7. Journal Watch 24(7):54-55, 2004 Coull AJ et al Population based study of early risk of stroke after transient ischaemic attack or minor stroke: implications for public education and organisation of services. BMJ 328:326,2004 <PubMed> PMID: [3] <Internet> [4]
8. Journal Watch 24(10):79, 2004 Eliasziw M, Kennedy J, Hill MD, Buchan AM, Barnett HJ; North American Symptomatic Carotid Endarterectomy Trial Group. Early risk of stroke after a transient ischemic attack in patients with internal carotid artery disease. CMAJ. 2004 Mar 30;170(7):1105-9. PMID: [5]
9. Gladstone DJ, Kapral MK, Fang J, Laupacis A, Tu JV. Management and outcomes of transient ischemic attacks in Ontario. CMAJ. 2004 Mar 30;170(7):1099-104. PMID: [6]
   - Johnston DC, Hill MD. The patient with transient cerebral ischemia: a golden opportunity for stroke prevention. CMAJ. 2004 Mar 30;170(7):1134-7. PMID: [7]
10. O'Rourke F, Dean N, Akhtar N, Shuaib A. Current and future concepts in stroke prevention. CMAJ. 2004 Mar 30;170(7):1123-33. PMID: [8]
11. Journal Watch 24(17):133, 2004 Diener HC, Bogousslavsky J, Brass LM, Cimminiello C, Csiba L, Kaste M, Leys D, Matias-Guiu J, Rupprecht HJ; MATCH investigators. Aspirin and clopidogrel compared with clopidogrel alone after recent ischaemic stroke or transient ischaemic attack in high-risk patients (MATCH): randomised, double-blind, placebo- controlled trial. Lancet. 2004 Jul 24;364(9431):331-7. PMID: [9]
12. Prescriber's Letter 11(10): 2004 Concomitant use of Aspirin and Clopidogrel (Plavix) in Cerebrovascular Disease Detail-Document#: [10] (subscription needed) [11]
13. Journal Watch 25(15):118, 2005 van Wijk I, Kappelle LJ, van Gijn J, Koudstaal PJ, Franke CL, Vermeulen M, Gorter JW, Algra A; LiLAC study group. Long-term survival and vascular event risk after transient ischaemic attack or minor ischaemic stroke: a cohort study. Lancet. 2005 Jul 7;365(9477):2098-104. PMID: [12]
    - Hankey GJ. Redefining risks after TIA and minor ischaemic stroke. Lancet. 2005 Jul 7;365(9477):2065-6. No abstract available. PMID: [13]
14. Coutts SB, Simon JE, Eliasziw M, Sohn CH, Hill MD, Barber PA, Palumbo V, Kennedy J, Roy J, Gagnon A, Scott JN, Buchan AM, Demchuk AM. Triaging transient ischemic attack and minor stroke patients using acute magnetic resonance imaging. Ann Neurol. 2005 Jun;57(6):848-54. PMID: [14]
15. Ay H et al, Transient ischemic attack with infarction: A unique syndrome? Ann Neurol 2005; 57:679 PMID: [15]
16. Rothwell PM et al, Effect of urgent treatment of transient ischaemic attack and minor stroke on early recurrent stroke (EXPRESS study): A prospective population-based sequential comparison Lancet 2007, 370:1432 PMID: [16]
17. Luengo-Fernandez R et al Effect of urgent treatment for transient ischaemic attack and minor stroke on disability and hospital costs (EXPRESS study): A prospective population-based sequential comparison. Lancet Neurol 2009 Mar; 8:235. PMID: [17]
18. Chandratheva A et al. Population-based study of risk and predictors of stroke in the first few hours after a TIA. Neurology 2009 Jun 2; 72:1941 PMID: [18]
19. Merwick A et al. Addition of brain and carotid imaging to the ABCD2 score to identify patients at early risk of stroke after transient ischaemic attack: A multicentre observational study. Lancet Neurol 2010 Nov; 9:1060. PMID: [19]
20. Callahan A et al. Risk of stroke and cardiovascular events after ischemic stroke or transient ischemic attack in patients with type 2 diabetes or metabolic syndrome: Secondary analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial. Arch Neurol 2011 Oct; 68:1245. PMID: [20]
21. Geriatric Review Syllabus, 7th edition Parada JT et al (eds) American Geriatrics Society, 2010
22. El Husseini N et al Depression and Antidepressant Use After Stroke and Transient Ischemic Attack Stroke March 29, 2012 <PubMed> PMID: [21] <Internet> [22]
23. NINDS Transient Ischemic Attack (TIA) Information Page [23]
    - Transient Ischemic Attack: NIH Institute & Center Resources [24]
24. National Guideline Clearinghouse
    - Management of patients with stroke or TIA: assessment, investigation, immediate management and secondary prevention. A national clinical guideline. Scottish Intercollegiate Guidelines Network ngc-guideline: [25]
    - Stroke. Diagnosis and initial management of acute stroke and transient ischaemic attack (TIA). National Collaborating Centre for Chronic Conditions (NICE) ngc-guideline: [26]
    - Stroke and transient ischaemic attacks: assessment, investigation, immediate management and secondary prevention (Singapore Ministry of Health) ngc-guideline: [27]

transient ischemic attack (TIA)