Michael Horowitz, MD Pittsburgh, PA

Michael Horowitz, MD Pittsburgh, PA

Introduction Cervical Artery Dissection occurs by a rupture within the arterial wall leading to an intra-mural Hematoma. A possible consequence is an acute occlusion of the vessel and risk for local thrombus or distal embolization. Bogousslavsky found an incidence of 2.5% in 1200 consecutive stroke patients. Under the age of 45, the incidence is much higher at 10-20% (Bogousslavsky and Pierre, 1992) Incidence is 2.6 per 100000 based on a community study (Schievink et al., 1993)

Introduction Most common sites: ICA 2-3 cm distal to the bifurcation and at the skull base VA: V3 between the C1 and C2 of the atlas loop before entering the dura, Proximal VA dissection is rare

Anatomy

Symptoms Unusual and unilateral sharp neck pain: ICA: anterolateral neck radiating to the mandible and ear (20-40%), VA: dorsal neck (50%) HA (80%) Pulsatile tinnitus (10-15%, more common in ICA dissection) Transient monocular blindness (10-15% in ICA dissection) TIA (10-20%) Metallic taste

Signs Horner s syndrome (40-50% in ICA dissections, VA dissection: 20 % central Horner s) Cranial nerve deficit (ICA dissection: 5-12% III-XII) Lower cranial deficits are more common in VA dissection Cerebral infarction

Sympathetic tract

Diagnosis: Doppler False lumen Sens. >90% (Seinke et al.) GE Website

Diagnosis: Doppler Caplan LR (2008) Dissections of brain-supplying arteries Nat Clin Pract Neurol 4: 34 42 10.

Diagnosis Semi-lunar shape hematoma is present from D#3 to 6M (Seinke et al., 1994) Caplan LR (2008) Dissections of brain-supplying arteries Nat Clin Pract Neurol 4: 34 42 10.

Diagnosis: MRI Caplan LR (2008) Dissections of brain-supplying arteries Nat Clin Pract Neurol 4: 34 42 10.

Diagnosis: CTA

Diagnosis: DSA

Pathogenesis Mild mechanical stress: coughing, head turning, sport activity Chiropractic maneuvers or direct trauma (Saver et al., 1992) FMD up to 15% of patients Heritable connective tissue disease : EDS, OI and Marfan s Iatrogenic Primary arteriopathy: Abnormal skin Biopsy in up to 50% of patients.

Pathogenesis: Primary CAD

Pathogenesis: Primary CAD Skin Bx. from a 126 pts. With scad and 29 healthy relatives were analyzed 57% of scad patients had abnormal morphology: in 43 patients, they repeatedly observed composite collagen fibrils and elastic fibers with fragmentation and minicalcifications. In 13 further patients, the dermis was significantly thinner than in healthy subjects. The collagen fibers contained fibrils with highly variable diameters. In a third group of 16 scad patients, the abnormalities were restricted to the elastic fibers (with fragmentation and minicalcifications) without significant alterations in the morphology of the collagen fibrils.

Pathogenesis: scad

Prognosis Recanalization rate is high with up to 85% normalization within 6 weeks to 3 months (Steinke et al.1994) Pseudoaneurysms develop in 5-40 %, do not increase the risk of distal embolus ( Guillon et al. 1999) Recurrence is low with <10% varying from 4 to 8 % ( Mokri et al.1987 ), up to 50 % in familial cases.

Treatment of cervical artery dissection: a systematic review and meta-analysis CADISP Study 2011 (largest study published in 2011) 982 patients 34 other studies: 22 Carotid, 3 VA and 9 for both 762 patients: 268 treated with antipltatelts (group 1) And 494 with anticoagulation ( group 2) One prospective study included 23 pts. On antiplatelts and 71 on anticoagulation (not randomized) A total of 14 deaths, 1.8% in each group A total of 15 strokes: 1.9% in group 1 and 2% in group 2 TIA or stroke: 7% in in group 1 and 3.8 in group 2: p=0.11 Stroke or death: 3.4% in group 1 and 3.8 %in group 2

Figure 1 Forrest plot comparing stroke rates in patients treated with anticoagulants versus antiplatelet agents. n, number affected; N, total number; RD, risk difference. Menon, R et al. J Neurol Neurosurg Psychiatry 2008;79:1122-1127 Copyright 2008 BMJ Publishing Group Ltd.

Figure 2 Forrest plot comparing combined stroke and transient ischaemic attack (TIA) rates in patients treated with anticoagulants versus antiplatelet agents. n, number affected; N, total number; RD, risk difference. Menon, R et al. J Neurol Neurosurg Psychiatry 2008;79:1122-1127 Copyright 2008 BMJ Publishing Group Ltd.

Figure 3 Forrest plot comparing combined stroke and death rates in patients treated with anticoagulants versus antiplatelet agents. n, number affected; N, total number; RD, risk difference. Menon, R et al. J Neurol Neurosurg Psychiatry 2008;79:1122-1127 Copyright 2008 BMJ Publishing Group Ltd.

Thrombolysis in cervical artery dissection Only four retrospective studies. These included 59 patients, all with carotid dissections. Seven were treated with IA urokinase, and 52 with IV TPA. In all but one study, almost all patients were treated within 3 h of stroke onset. One patient developed hemiplegia and aphasia 40 min after the start of tpa infusion caused by recurrent cerebral infarction and died 3 days later. There was one symptomatic ICH. All but one study performed CT imaging the day after treatment, and in the 46 patients scanned there were no additional ICHs. No worsening of local signs was reported. Four patients died, one due to stroke during thrombolysis as described above and the others for reasons unrelated to thrombolysis

Thrombolysis in cervical artery dissection The complication rate was compared with that from the SITS-MOST registry in 6483 patients receiving intravenous thrombolysis within 3 h of stroke onset. The rate of symptomatic ICH, and any ICH, in SITS-MOST was 1.7% and 7.9%, respectively, compared with 1.9% and 1.9%, respectively, in the dissection cases

Angioplasty and stenting in cervical artery dissection Eight studies met the selection criteria, they were non-randomised, retrospective and included 97 procedures in 93 patients. Stenting was performed for a variety of indications, including traumatic and non-traumatic dissection, acutely for tight stenosis or later for DA. High technical success rate with only (5.2%) technical failures, most often because of vessel tortuosity and difficulty accessing the lesion, and in one case following creation of an intimal flap. There were few perioperative complications; three TIAs (3.1%) and no strokes. Excluding perioperative events during the first 30 days of follow-up there was one death due to myocardial infarction but no recurrent strokes. Follow-up after 30 days was of variable duration, and there were three TIAs and two contralateral strokes but no ipsilateral strokes. Angiographic results were good with resolution of stenosis, where present, in almost all cases, and only two re-stenoses on follow-up imaging.

Intracranial Dissections More complex situation Media is thinner intracranially therefore increased risk for SAH

Summary Recommendations Asymptomatic Extracranial Dissection (non-ischemic neurologic symptoms) Antiplatelet therapy with goal of preventing ischemic events Symptomatic Extracranial Dissection (ischemic neurologic symptoms) Hydrate BP control Antiplatelet therapy = Anticoagulation (>6 months) ASA vs other agents (?) Thrombolysis for acute events (use CT and MR to evaluate ischemic volume) For recurrent events add second pharmacologic agent For recurrent events on maximum medical therapy consider stenting or sacrifice Intracranial Dissection Antiplatelet therapy Vessel Sacrifice Stenting (?)

Prognosis Vessel normalization can be as high as 85% at 6 months Most dissecting extracranial aneurysms do not resolve Recurrence rate for extracranial dissections at 3 months is 2% and may occur in multiple vessels at once. Multiple vessel involvement more common in familial cases. Patient tend to by younger (mean age 36) Rate of recurrent ischemic symptoms (stroke and/or TIA) 0-13%. Most likely in the 1% range. Extracranial ICA dissection presenting with ischemic symptoms had 25% unfavorable outcome at 3 months (Rankin Score >2) Extracranial VA dissection with ischemic symptoms had 8% unfavorable outcome at 3 months (Rankin Score >2) Driven by stroke severity at onset Long terms outcomes complete or excellent recovery in 70-85% of patients with extracranial dissections Major disabling deficits 10-25% Death in 5-10%