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Evaluation of Patients with Transient Ischemic Attack Rodney Smith, MD Clinical Assistant Professor Department of Emergency Medicine University of Michigan Ann Arbor, MI. Introduction. A 55 year old male presents to the emergency department with acute onset of
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Evaluation of Patients with Transient Ischemic AttackRodney Smith, MDClinical Assistant ProfessorDepartment of Emergency MedicineUniversity of MichiganAnn Arbor, MI
Introduction • A 55 year old male presents to the emergency department with acute onset of • Left arm weakness: Unable to lift left arm off of lap • Symptoms improved on the way to the hospital
Introduction • PMHx: Hypertension • Takes enalapril • ROS: • No headache • No other neurologic symptoms • Social Hx: • Smokes 1 ppd
Introduction • Physical Exam • Overweight, in NAD • 160/90, 80, 14, 37.5C • Right carotid bruit • Heart with regular rate and rhythm; No murmur
Introduction • Neuro exam • oriented to person, place, and time • fluent speech • CN II-XII intact • motor 4/5 strength in left upper extremity • sensory subjective decrease in pinprick in left upper extremity compared to the right • DTR +2 except at left biceps +3 • Gait steady • cerebellar intact finger to finger and finger to nose • no extensor plantar response.
Objectives • What is a transient ischemic attack (TIA)? • What is the differential diagnosis of patients with possible TIA? • What is the ED approach to TIA? • What is the treatment and disposition of patients with TIA?
Transient Ischemic Attack • What is a TIA? • Acute loss of focal cerebral function • Symptoms last less than 24 hours • Due to inadequate blood supply • Thrombosis • Embolism
Transient Ischemic Attack • Acute loss of focal cerebral function • Motor symptoms • Weakness or clumsiness on one side • Difficulty swallowing • Speech disturbances • Understanding or expressing spoken language • Reading or writing • Slurred speech • Calculations
Transient Ischemic Attack • Acute loss of focal cerebral function • Sensory symptoms • Altered feeling on one side • Loss of vision on one side • Loss of vision in left or right visual field • Bilateral blindness • Double vision • Vertigo
Transient Ischemic Attack • Non-focal Symptoms • Generalized weakness or numbness • Faintness or syncope • Incontinence • Isolated symptoms • Vertigo or loss of balance • Slurred speech or difficulty swallowing • Double vision
Transient Ischemic Attack • Non-focal Symptoms • Confusion • disorientation • impaired attention/concentration • diminution of all mental activity • distinguish from isolated language, memory, or visual-spatial perception problems
Transient Ischemic Attack • Acute loss of focal cerebral function • Abrupt onset • Symptoms occur in all affected areas at the same time • Symptoms resolve gradually • Symptoms are “negative”
Transient Ischemic Attack • Symptoms last less than 24 hours • Most last less than one hour • Less than 10 percent > 6 hours • Amaurosis fugax up to five minutes • Gradual resolution
Differential Diagnosis • Migraine with aura • Positive symptoms • Spread over minutes • Visual disturbances • Somatosensory or motor disturbance • Headache within 1 hour
Differential Diagnosis • Aura without Headache • Gradual onset with spread over minutes OR • Positive visual symptoms • Headache totally absent or mild • No prior symptoms of classic migraine
Differential Diagnosis • Aura without Headache • 50 patients with case control TIA patients • 10 year follow-up • Mean age 48.7 (vs. 62.1) • 60% male (vs. 68%) • Fewer cardiovascular risk factors
Differential Diagnosis • Aura without Headache • 98% Visual symptoms • 30% with other symptoms • 26% sensory • 16% aphasia • 6% dysarthria • 10% weakness
Differential Diagnosis • Aura without HA • Onset of symptoms in minutes • Over 50% with onset over > 5 min.
Differential Diagnosis • Aura without HA • Duration of symptoms in minutes • 20% with slight headache • 20% with prior headaches without aura
Differential Diagnosis • Partial (focal) seizure • Positive sensory or motor symptoms • Spread quickly (60 seconds) • Negative symptoms afterward (Todd’s paresis) • Multiple attacks
Differential Diagnosis • Transient global amnesia • Sudden disorder of memory (confusion) • Antegrade and often retrograde • Recurrence 3% per year • Etiology unclear • Migraine • Epilepsy (7% within 1 year) • Unknown
Differential Diagnosis • Transient global amnesia • No difference in vascular risk factors compared with general population • Fewer risk factors when compared with TIA patients • Prognosis significantly better than TIA
Differential Diagnosis • Structural intracranial lesion • Tumor • Partial seizures • Vascular steal • Hemorrhage • Vessel compression by tumor
Differential Diagnosis • Intracranial hemorrhage • ICH rare to confuse with TIA • Subdural hematoma • Headache • Fluctuation of symptoms • Mental status changes
Differential Diagnosis • Multiple sclerosis • Usually subacute but can be acute • optic neuritis • limb ataxia • Age and risk factors • Signs more pronounced than symptoms
Differential Diagnosis • Labyrinthine disorders • Central vs. Peripheral vertigo • Ménière's disease • Benign positional vertigo • Acute vestibular neuronitis
Differential Diagnosis • Metabolic • Hypoglycemia • Hyponatremia • Hypercalcemia • Peripheral nerve lesions • Entrapments • Painful quality
Likelihood of TIA • Diagnosis of TIA • Kraaijeveld, et al. 1984 • 56 patients evaluated by 2 of 8 “senior neurologists” • Decide if TIA (yes or no) • If yes, territory involved (carotid, vertebro-basilar, either, both) • Is conclusion firm or doubtful?
Likelihood of TIA • Clinical criteria • Time course • Symptoms of carotid TIA • Symptoms of vertebro-basilar TIA • Symptoms of uncertain territory • Symptoms explicitly not TIA
Likelihood of TIA • Agreement on 48 of 56 patients (85.7%) • 36 with TIA • 12 Not TIA • 8 of 56 disagreement • 4 of these, both listed firm diagnosis
Likelihood of TIA • TIA yes or no • kappa = 0.65 • TIA circulation involved • kappa = 0.31
Emergency Department Evaluation • History • Characteristics of the attack • Associated symptoms • Risk factors • Vascular Disease • Cardiac Disease • Hematologic Disorders • Smoking • Prior TIA
Emergency Department Evaluation • Physical Examination • Neurologic Exam • Carotid Bruits • Cardiac Exam • Peripheral Pulses
Emergency Department Evaluation • EKG • CBC, Coags, and Chemistries • Chest Xray • Head CT without contrast • Expedite if early presentation
Decision Point • Symptom vs. Disease • Significant carotid artery stenosis • Cardiac embolism • Admission vs. Discharge • Traditional approach • Trend toward outpatient evaluation
Likelihood of Early Stroke • Prognosis after TIA • Dennis et al. Oxfordshire, UK 1981 - 1986 • Prospective community-based study • Incident TIA • No history of prior stroke • Whisnant, et al. Rochester, MN 1955 - 1969 • Retrospective community-based study • First-ever TIA
Likelihood of Early Stroke • Stroke rate after TIA • Annual rate during 5-year follow-up • 6.7% Oxfordshire • 6.6% Rochester, MN
Likelihood of Early Stroke • Stroke Rate After TIA • Percent (95% CI)
Carotid Endarterectomy and Stroke • 70% stenosis or greater • Best medical therapy vs. CEA
Carotid Endarterectomy and Stroke • 50 - 69% stenosis • Best medical therapy vs. CEA
Diagnosis of Carotid Stenosis • Carotid Duplex Ultrasound • Sensitivity of 94 - 100% for > 50% stenosis • May overdiagnose occlusion • Non-invasive
Diagnosis of Carotid Stenosis • Magnetic Resonance Angiography • Similar sensitivity to carotid ultrasound • Overestimates degree of stenosis • Gives information about vertebrobasilar system • Accuracy of 62% in detecting intracranial pathology • Cost and claustrophobia
Diagnosis of Carotid Stenosis • Cerebral Angiography • Gold standard for diagnosis • Invasive, with risk of stroke of up to 1% • For patients with positive ultrasound • For patients with occlusion on ultrasound • First test if intracranial pathology suspected
Cardiogenic Embolism • Major risk factors • Atrial fibrillation • Mitral stenosis • Prosthetic cardiac valve • Recent MI • Thrombus in LV or LA appendage • Atrial myxoma • Infective endocarditis • Dilated cardiomyopathy
Cardiogenic Embolism • Minor risk factors • Mitral valve prolapse • Mitral annular calcification • Patent foramen ovale • Atrial septal aneurysm • Calcific aortic stenosis • LV regional wall motion abnormality • Aortic arch atheromatous plaques • Spontaneous echocardiographic contrast
Echocardiogram • Yield < 3% in undifferentiated patients • Higher with risk factors • Indications • Age < 50 • Multiple TIAs in more than one arterial distribution • Clinical, ECG, or CXR evidence suggests cardiac embolization
TIA Evaluation • ED Disposition • Admission • Clear indication for anticoagulation • Severe deficit • Crescendo symptoms • Other indication for admission