J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Transient Ischemic Attack Patient Update:

The Optimal Management of Emergency Department Patients

With Suspected Cerebral Ischemia

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Cerebral Ischemia and Transient Ischemic Attacks: Definitions and a Historical

Perspective

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

J. Stephen Huff, MDJ. Stephen Huff, MD

Associate Professor of Associate Professor of Emergency Medicine and NeurologyEmergency Medicine and NeurologyUniversity of Virginia Health SystemsUniversity of Virginia Health Systems

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

CME Disclosure StatementCME Disclosure Statement

Board Member - FERNE

Foundation for Education and Research in Neurological Emergencies

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Session ObjectivesSession Objectives

Determine how the definition of TIA is evolving and how this relates to the presentation of TIA patients to the Emergency Department

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Definitions - subgroupsDefinitions - subgroups

• TIA– Transient Ischemic Attack

– Duration minutes to 24 hours

• RIND– Reversible Ischemic Neurologic Deficit

– Deficit resolves within 6 weeks

• Stroke - Enduring symptoms

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Older definitionsOlder definitionsTIA’s - unpredictableTIA’s - unpredictable

• Old – “rule of thirds”– 1/3 stroke, 1/3 more TIA’s, 1/3 no further

• Neuroimaging / assessments– Angiography

– PEG (pneumoencephalogram)

– EEG

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

PathophysiologyPathophysiology

• Thrombotic– Recurrent episodes same pattern

• Embolic– Multiple episodes of different patterns

Fisher CM: NEJM 2002;347:1642-3

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

EpidemiologyEpidemiology

• Annual incidence 200,000 – 500,000– Estimated from patients seeking care

– may be higher – not seeking attention

• 5 million US given diagnosis of TIA

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

US TIA Estimates from Different Population US TIA Estimates from Different Population Based StudiesBased Studies

Ovbiagele B et al. Stroke 2003;34(4):919-24.

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Changes in Diagnostic EvaluationChanges in Diagnostic Evaluation

• Change in imaging– CT

– Ultrasound

– MRI

• Defining natural history of process

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Continuum or Subgroups?Continuum or Subgroups?

• CT findings in 2082 patients

• Anterior circulation; CT’s > 24 hours – TIA’s - 13% with CT findings of stroke

– RIND – 35% with CT findings

– Minor stroke – 49% with CT findings

Koudstaal PJ et al. J Neurol Neurosurg Psych 1992;55:95-97

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Continuum or Subgroups?Continuum or Subgroups?

• TIA’s– More infarcts the longer the duration

– Stroke still imaged (CT) in patients with TIA’s lasting less than one minute

Koudstaal PJ et al. J Neurol Neurosurg Psych 1992;55:95-97

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Continuum or Subgroups?Continuum or Subgroups?

• Suggested that the ischemic syndromes were not subgroups with different natural history

• Ischemic syndromes on a continuum

Koudstaal PJ et al. J Neurol Neurosurg Psych 1992;55:95-97

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

CT and TIA’sCT and TIA’s

• CT’s within 48 hours of presentation– 322 patients with TIA

– 4% new infarct

– 21% old infarction

– 1.2 % non-ischemic cause

• CT positive for acute stroke predicted increased risk of additional stroke

Douglas VC et al: Stroke 2003;34:2894-8

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

MRI versus CTMRI versus CT

• DWI imaging on MRI can detect ischemic lesions within minutes of the event

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

MRI abnormalities and TIAMRI abnormalities and TIA

• 129 consecutive patients– MRI within 14 days of TIA

• DWI showed 44% abnormal MRI– Associated with longer symptoms

– Associated with disturbance of cerebral functions• Aphasia, spatial neglect, hemianopia

Inatomi Y et al: Neurology 2004;62:376-380

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Frequency of Positive Diffusion MRI:Frequency of Positive Diffusion MRI:5 Reported Series of TIAs5 Reported Series of TIAs

Ovbiagele B et al. Stroke 2003;34:919-24

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

TIA Definition ChangingTIA Definition Changing

• TIAs almost all resolve within 1 hour

• Most last less than 10 minutes

• <15% patients with symptoms lasting > 1 hour will have resolution at 24 hours

• Several series of patients with “normal” neuro exams who underwent acute MRI scanning have demonstrated injury

Albers GW et al. N Engl J Med 2002;347:1713–1716

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

TIA Definition ChangingTIA Definition Changing

• Current – time-based definition

• Proposed – tissue-based definition

Albers GW et al. N Engl J Med 2002;347:1713–1716

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

TIA Working Group DefinitionTIA Working Group Definition

• “Brief episode of neurologic dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction”

– Implies need for MRI before diagnosis

Albers GW et al. N Engl J Med 2002;347:1713–1716

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Risk stratification TIAs has changedRisk stratification TIAs has changed

• In past – regarded as low risk events– Workup over weeks

• Contemporary view– High risk sentinel events– Prompt evaluation, interventions

J. Stephen Huff, MD, FACEPJ. Stephen Huff, MD, FACEP

Questions?Questions?

www.ferne.orgjshuff@virginia.edujshuff@virginia.edu

ferne_clindec_2008_tia_huff_definitions_extended_062508_final