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Ischemic Posterior Circulation Stroke Christopher Lewandowski, M.D. Residency Program Director Department of Emergency Medicine Henry Ford Hospital, Detroit, MI Sunitha Santhakumar, M.D. Department of Emergency Medicine Henry Ford Hospital, Detroit, MI. Case Study. HPI:
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Ischemic Posterior Circulation Stroke Christopher Lewandowski, M.D.Residency Program Director Department of Emergency Medicine Henry Ford Hospital, Detroit, MI Sunitha Santhakumar, M.D.Department of Emergency Medicine Henry Ford Hospital, Detroit, MI
Case Study • HPI: The patient is 41 y.o. male, with a past history of alcohol abuse, hypertension who presents to the ED with a chief complaint of right -sided weakness, slurred speech, and loss of balance. The symptoms began 90 minutes prior to arrival.
Case Study • PMHx: • Alcohol Abuse, quit for 3 years • Hypertension • Seizures, Generalized, none for past 7 years • Medications • Dyazide • Social Hx • Smoking- 2 pack per day • ROS: Mild dizzy spells for the past 2 weeks, each lasting 5-10 minutes
Case Study • Physical Exam: • BP- 149/79, P-100, RR-18, T-36.9 • A&Ox3 on presentation, later became stuporous • CN: dysarthria, pupils: R 3.5/ L 3.0 reactive • L facial droop, gaze palsy to the L • Motor: R arm and R leg weakness (3/5) • Sensory: Decreased to light touch and pinprick on R • Coordination: dysmetria on R (not out of proportion to weakness) • NIH Stroke Scale score = 14
Epidemiology • 20% of all strokes • The posterior circulation – 20% of the CBF • Basilar artery occlusion – 8% - 14% of posterior circulation strokes • Mortality: 90% for BAO 4% other posterior strokes • Unfavorable outcome 20%-60%
Posterior Circulation Stroke Characteristics Clinical Findings: • The 5 Ds: Dizziness, Diplopia, Dysarthria, Dysphagia, Dystaxia • Hallmarks: Crossed findings • Cranial nerve deficits - Ipsilateral • Motor / Sensory deficits - Contralateral
Posterior Circulation Stroke Prodrome • Prodrome very common • Occurs in 60% of patients with Basilar artery thrombosis • Common Prodomal Symptoms (in order of frequency) • Vertigo and Nausea (30%) • Headache, Neckache (20%) • Hemiparesis (10%) • Dysarthria, Diplopia (10%) • Hemianopia ( 6%) Ferbert, Stroke 1990
Was this Patient’s Dizziness Central or Peripheral Central Peripheral Intensity Mild Severe Tinnitis Rare Common CN findings Frequent None Nystagmus: Visual fixation No inhibition Inhibits Horizontorotary Rare Common Latency None 3-40 sec Fatigue None yes
Posterior Circulation Stroke: Syndromes • VBI, brainstem TIAs: • Occur over days-weeks • Intermittent fluctuating brainstem sx • Dizziness plus cranial nerve symptoms • Rarely dizziness alone
Posterior Circulation Stroke: Syndromes • Locked-in Syndrome • Basilar Artery or bilat. vertebral art. Occlusion • Progressive awake quadriplegia • Bilateral facial and oropharyngeal palsy • Preservation of cortical function and vertical gaze • Patient is awake and alert until RAS involved • >90% in hospital mortality
Confirm the Diagnosis (Emergent) CT Scan MRI Blood studies Evaluation of Stroke Etiology (Inpatient) MRA / Angiography Echo / TEE TCD Carotid Doppler How do you evaluate this patient?
What is the prognosis for this patient ? • All Posterior Circulation Strokes • New England Medical Center Posterior Circulation Stroke Registry: • Mortality = 4% • Minor or no Disability = 79% • Locked In Syndrome (Basilar artery occlusion) • Mortality > 90% • How do you know if a patient will progress to locked-in syndrome ? Observation
What are your treatment options? • Conservative Treatment • Antiplatelet and Antithrombotic • Thrombolytic Treatment • Intravenous: within 3 hours symptom onset and the patient meets all treatment criteria • Intra-Arterial Therapy: infusion of thrombolytic agent into vessel or clot within 24 hours of onset of symptoms
Posterior Circulation Stroke: Treatment • Conservative Treatment • Antiplatelet and Anti thrombotic Therapy • Uncontrolled, Retrospective Studies , 1950s & 1960s • Compared to historical controls, patients treated with heparin had lower mortality (8-15% vs. 40-60%) • Stopped progression of VBI to infarction • TOAST Trial • No evidence to support LMWH in acute stroke
Posterior Circulation Stroke: Treatment • Intravenous Thrombolysis • NINDS rt-PA Acute Stroke Trial • t-PA approved within 3 hours of symptom onset • Few posterior circulation strokes
Posterior Circulation Stroke: Treatment • Intra-arterial Thrombolysis • No randomized controlled trials completed • Multiple small series and reports • Results (Over 200 patients treated) • Mortality 20-60% , assoc. with lack of recanalization • Favorable outcomes in 25%-60% • ICH rate low, 0-15%
Posterior Circulation Stroke Future Treatment • Intra-arterial Thrombolysis • Superselective approach, micro-catheters • Angioplasty • Angio-jet
Case Study: Outcome • The patient mental status deteriorated, repeat NIH-SS score was 22 • He received intravenous thrombolysis • He had significant early improvement but without complete resolution of symptoms • On day 4, the NIH - SS score was 10 • MRA : L sup. cerebellar art. and R&L Ant-Inf cerebellar arteries were non-visualized, • Cardiac evaluation was negative • He was discharged on Coumadin to Rehab
Summary • Posterior Circulation Strokes are characterized by the 5D’s and crossed findings • Maintain a high index of suspicion for prodromal symptoms - vertigo with CN sx • The locked-in syndrome consists of quadriplegia, bilateral facial and oropharyngeal palsy; but preservation of cortical function and vertical gaze
Summary • The prognosis for vertebrobasilar ischemia is generally good, except for locked-in syndrome (basilar artery occlusion) • Treatment consists of conservative therapy (aspirin and heparin) or IV thrombolysis (<3 hrs) or IA thrombolysis (up to 24 hours)