Spontaneous Dissection of the Carotid and Vertebral Arteries

To the Editor: In the review article on spontaneous dissection of the carotid and vertebral arteries (March 22 issue), 1 Dr. Schievink recommends therapeutic anticoagulation unless the dissection extends intracranially. Intraarterial angiography is often necessary to establish whether such an extension is present. It is believed that there is an increased risk of intracranial bleeding on anticoagulation of an intracranial arterial dissection. However, there is no good evidence to support this view. In the absence of hard data, this approach is largely empirical. It would be appropriate to qualify this recommendation until better data are available. To the Editor: Although the . . .