2. Extracranial dissection is easily diagnosed by ultrasound

3. Vertebral Artery Dissection (VAD) –43% of are spontaneous in nature –31% are associated with cervical spine manipulation –16% from trivial trauma –10% from major trauma Haldeman et al. Spine. 1999; 15: 24: 785-94.

4. VAD Relatively rare. (1966-2007=34 studies, 762 pts of VAD- JNNP,2008) Presenting symptoms: –Unilateral posterior headache Pain may radiate to neck and face –Dysarthria –Dysphagia –Ataxia –Double vision –Limb or trunk numbness (Caplan et al.1985)

5. VAD Anatomical level: Segment III (petrous level) From the superior of C2 foramen to the dura, most of the spontaneous dissected region. Can extended to segment IV(upstream) with neurological s/s. Most injured rotated point.

6. Segment I: Rises from the Subclavian artery to the transverse foramen of C6

7. Segment II: Within the transverse foramina from C6-C2 (the most massage injured level)

8. Segment IV: From the dura into the cranium

9. Vertebral Artery Dissection Presenting Findings and Predictors of Outcome V1= 20% V2 =35% V3 =34% V4= 11% (Stroke, 2006) Younger age+ Low NIHSS score => are good prognostic outcome

10. VAD Diagnosis is same as in carotid dissection. Treatment includes early anticoagulation or followed by anti-platelet therapy.

11. Account for 20 % of stroke younger than 45 yrs old. 70-80% of extracranial carotid, 15% of extracranial VA. Trauma, respiratory infection, underlying arteriopathy played some roles in etiology. Local pain, headache, and ipsilateral Horner’s- s/s of Triad. Hours before retina or cerebral stroke. Prognosis is much better in extracranial than intracranial dissection. Recurrence is rare. SAH can be happened in intracranial dissection sometimes. Anti-platelet or anti-coagulation equally.