Ischemic Posterior Circulation Stroke Christopher Lewandowski, M. D 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 54 1 54

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: Medications Social Hx 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: Anatomy

Posterior Circulation Stroke: Anatomy

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

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

How do you evaluate this patient? Confirm the Diagnosis (Emergent) CT Scan MRI Blood studies Evaluation of Stroke Etiology (Inpatient) MRA / Angiography Echo / TEE TCD Carotid Doppler

Case Study: CT Scan

Baseline CT scan

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

Case Study: MRI - DWI <12 Hours 4 Days

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)