Vertigo After a Car Accident: Vertebral Artery Dissection?

ANSWER: Right vertebral artery dissection.

  Figure 2.

As illustrated by the MRA study in Figure 1 (previous page) filling of the right vertebral artery is compromised compared with that of the left, a finding that confirms the diagnosis of arterial dissection. Figure 2 presents a 3-D reconstruction of the arterial circulation of the neck. The thinning of the right vertebral artery is again demonstrated. This lesion was most likely related to the patient’s motor vehicle accident 10 days earlier. A brain MRI/MRA showed multiple strokes in the posterior circulation and a pending basilar arterial occlusion.

The patient was admitted to the hospital. Treatment with heparin(Drug information on heparin) and warfarin(Drug information on warfarin) produced a gradual improvement in symptoms. She was discharged home 6 days later and did well.

Discussion
Vertebral arterial dissection is a rare cause of neck pain and also a rare cause of stroke. The diagnosis should be considered after major neck trauma or whenever neck injury is followed by neurologic symptoms or signs. Pain is usually present in the posterior-lateral neck and may initially mimic a muscular strain. Neurologic symptoms are caused by emboli or thrombus, which originate at the site of the vascular injury and usually present in a delayed fashion, classically within 1 to 2 weeks of injury. Vertigo, ataxia, and cranial nerve deficits are the usual results of posterior circulation, TIAs, or strokes. Although minor trauma rarely causes vascular injury, cases of vertebral artery dissection have been reported following very low-energy mechanisms, even prolonged upward gaze while painting a ceiling or other overhead object.

For low-risk patients, duplex ultrasonography is a good screening test that is relatively inexpensive and involves no IV contrast, no radiation, and essentially no risk. For patients in whom concern is high, CT angiogram or MR angiogram should be performed. If dissection of the carotid or vertebral artery is diagnosed, a neurosurgeon or at least a neurologist should be consulted. Operative intervention is rarely required, but most cases are managed with prolonged anticoagulation to prevent stroke, until vascular healing is complete. See the Table (below) for more details.