Posterior Circulation Stroke

Transcription

1 Posterior Circulation Stroke Brett Kissela, MD, MS Professor and Chair Department of Neurology and Rehabilitation Medicine Senior Associate Dean of Clinical Research University of Cincinnati College of Medicine Chief of Research Services, UC Health Disclosures (last 5 years) Allergan, consultant/honoraria Ipsen, consultant AbbVie and Janssen; adjudication of stroke events for a clinical trial None of these disclosures are relevant to this talk. Outline: Epidemiology Anatomy A few posterior stroke syndromes Treatment Prognosis 1

2 Epidemiology The posterior circulation 20% of the CBF, about 20% of all strokes Basilar artery occlusion 8% - 14% of posterior circulation strokes Unfavorable outcome 20%-60% Prognosis 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 lockedin syndrome? Observation Anatomy 2

3 Anatomy Clinical characteristics Clinical Findings: The 5 Ds: Dizziness, Diplopia, Dysarthria, Dysphagia, Dystaxia Hallmarks: Crossed findings Cranial nerve deficits Ipsilateral Motor / Sensory deficits - Contralateral Clinical characteristics The most frequent posterior circulation symptoms were: dizziness (47%) unilateral limb weakness (41%) dysarthria (31%) headache (28%) nausea or vomiting (27%) New England Medical Center Posterior Circulation Registry. Arch Neurol. 2012;69(3):

4 Pontine Warning syndrome Motor fluctuation that resembles the so-called capsular warning syndrome Clinical features cannot definitely distinguish between these 2 syndromes Waxing and waning hemiparesis Plaque in the basilar artery at the orifice of the branch to the pons, resulting in paramedian pontine infarction Clinical characteristics--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%) dissection? Hemiparesis (10%) Dysarthria, Diplopia (10%) Hemianopia ( 6%) Ferbert, Stroke 1990 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 4

5 Top-of-the-Basilar syndrome Upper brainstem and diencephalic ischemia occlusion of the rostral basilar artery, usually by an embolus. Symptoms: Change in level of consciousness Visual symptoms--hallucinations and/or blindness Third nerve palsy and pupillary abnormalities Motor abnormalities can include abnormal movements or posturing Treatment Acute (acute stroke therapy eligible): Same as all other acute stroke patients Caveats: More aggressive (worse outcomes) especially basilar artery occlusion More ischemic tolerance? Longer time window? UNTIL RECENTLY: No randomized controlled clinical trials in posterior circulation only; small numbers of posterior circulation events in large trials to date 5

6 Treatment BEST Trial Abstract, World Stroke Congress Acute Basilar Artery Occlusion: Endovascular Interventions vs Standard Medical Treatment Phase 3 RCT testing endovascular therapy (EVT) vs medical management for basilar artery occlusions within 8 hours onset. Treatment BEST Trial Endovascular treatment thrombolysis, mechanical thrombectomy, stenting, or a combination of all these approaches. Solitaire FR is preferred, other devices allowed. Standard medical therapy If pt meets criteria for IV rt-pa within 4.5 h of stroke onset, standard dosing All patients will receive standard medical therapy. The standard medical therapy conforms with the current American Heart Association/American Stroke Association guidelines. Treatment BEST Trial Stopped early at 131 pts by DSMB significant crossovers in last quarter of trial related to loss of equipoise 21% in medical management arm ended up with EVT Given time window, only 37% of pts got IV rtpa 6

7 Treatment BEST Trial Nonsignificant primary endpoint (mrs 0-3) but 42.4% mrs 0-3 in EVT group compared to 32.3% in control arm (p=0.23) 7.6% with SICH in EVT group compared to none in control arm Mortality less in EVT group (33 vs 38.5%) All subgroups except for vert occlusion (n=12) favored EVT Per protocol and as treated results showed greater effects (20-22% absolute differences in mrs 0-3). Treatment BASICS Trial Ongoing trial in Netherlands Medical management (IV tpa if eligible) vs EVT (+/- IV tpa if eligible; EVT initiated by 6 hours) Should continue? There may be enough data for a Class IIa, Level of Evidence B recommendation supporting EVT for BA occlusions, and the question is answered well enough and equipoise is lost 7

8 Treatment Conservative management (not acute stroke therapy eligible) Historically, heparin has been considered in the treatment of posterior circulation strokes, based upon uncontrolled trials showing benefit compared to historical controls Treatment--Dissection Acute/Hyperacute: available evidence suggests that treatment with thrombolytic therapy should not be withheld for eligible patients with very early acute ischemic stroke due to extracranial cervical artery dissection Endovascular repair case reports 8

9 Treatment--Dissection Not acute: Antithrombotics vs anticoagulation open-label, assessor-blind pilot trial (CADISS) 250 subjects with extracranial carotid and vertebral dissection 1:1 antiplatelet vs anticoagulant treatment for 3 mo no significant difference between the two treatment groups; ipsilateral ischemic stroke occurred in 3 of 126 (2 percent) in the antiplatelet group and 1 of 124 (1 percent) in the anticoagulant group (odds ratio 0.34, 95% CI ). 1 SAH in anticoag group, no deaths Treatment--Dissection Not acute: Antithrombotics vs anticoagulation CADISS: low stroke rate, rare outcome events Neither treatment superior; definitive trial impossible (would take >10K enrollees) Two meta-analyses: 1600 and 1300 pts respectively No difference in recurrent stroke found with antiplatelet agents vs anticoag Summary Posterior Circulation Strokes are characterized by the 5D s and crossed findings Maintain a high index of suspicion for posterior circulation events: prodromal symptoms - vertigo with CN sx Weird syndromes top-of-basilar, etc The locked-in syndrome consists of quadriplegia, bilateral facial and oropharyngeal palsy; but preservation of cortical function and vertical gaze 9

10 Summary The prognosis for vertebrobasilar ischemia is not uniformly bad, except for basilar artery occlusion Treatment acutely similar to anterior circulation strokes (IV/IA treatment as appropriate) Caveats poor prognosis, maybe a little more ischemia resistance/less bleeding 10