1. J. Stephen Huff, MD, FACEP Transient Ischemic Attack Patient Update: The Optimal Management of Emergency Department Patients With Suspected Cerebral Ischemia

2. J. Stephen Huff, MD, FACEP Cerebral Ischemia and Transient Ischemic Attacks: Definitions and a Historical Perspective

3. J. Stephen Huff, MD, FACEP J. Stephen Huff, MD Associate Professor of Emergency Medicine and Neurology University of Virginia Health Systems

4. J. Stephen Huff, MD, FACEP CME Disclosure Statement Board Member - FERNE Foundation for Education and Research in Neurological Emergencies

5. J. Stephen Huff, MD, FACEP Session Objectives Determine how the definition of TIA is evolving and how this relates to the presentation of TIA patients to the Emergency Department

6. J. Stephen Huff, MD, FACEP Definitions - subgroups TIA –Transient Ischemic Attack –Duration minutes to 24 hours RIND –Reversible Ischemic Neurologic Deficit –Deficit resolves within 6 weeks Stroke - Enduring symptoms

7. J. Stephen Huff, MD, FACEP Older definitions TIA’s - unpredictable Old – “rule of thirds” –1/3 stroke, 1/3 more TIA’s, 1/3 no further Neuroimaging / assessments –Angiography –PEG (pneumoencephalogram) –EEG

8. J. Stephen Huff, MD, FACEP Pathophysiology Thrombotic –Recurrent episodes same pattern Embolic –Multiple episodes of different patterns Fisher CM: NEJM 2002;347:1642-3

9. J. Stephen Huff, MD, FACEP Epidemiology Annual incidence 200,000 – 500,000 –Estimated from patients seeking care –may be higher – not seeking attention 5 million US given diagnosis of TIA

10. J. Stephen Huff, MD, FACEP US TIA Estimates from Different Population Based Studies Ovbiagele B et al. Stroke 2003;34(4):919-24.

11. J. Stephen Huff, MD, FACEP Changes in Diagnostic Evaluation Change in imaging –CT –Ultrasound –MRI Defining natural history of process

12. J. Stephen Huff, MD, FACEP 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

13. J. Stephen Huff, MD, FACEP 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

14. J. Stephen Huff, MD, FACEP 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

15. J. Stephen Huff, MD, FACEP CT 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

16. J. Stephen Huff, MD, FACEP MRI versus CT DWI imaging on MRI can detect ischemic lesions within minutes of the event

17. J. Stephen Huff, MD, FACEP MRI 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

18. J. Stephen Huff, MD, FACEP Frequency of Positive Diffusion MRI: 5 Reported Series of TIAs Ovbiagele B et al. Stroke 2003;34:919-24

19. J. Stephen Huff, MD, FACEP TIA Definition Changing TIAs almost all resolve within 1 hour Most last less than 10 minutes 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

20. J. Stephen Huff, MD, FACEP TIA Definition Changing Current – time-based definition Proposed – tissue-based definition Albers GW et al. N Engl J Med 2002;347:1713–1716

21. J. Stephen Huff, MD, FACEP TIA 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

22. J. Stephen Huff, MD, FACEP Risk stratification TIAs has changed In past – regarded as low risk events –Workup over weeks Contemporary view –High risk sentinel events –Prompt evaluation, interventions

23. J. Stephen Huff, MD, FACEP Questions? www.ferne.org jshuff@virginia.edu www.ferne.org ferne_clindec_2008_tia_huff_definitions_extended_062508_final