Ultrasound findings of bilateral hypoplasia of the vertebral arteries associated with a persistent carotid-hypoglossal artery.

We present a 31-year-old female who was admitted to our neurology department for vertigo, partial left-sided hemihypesthesia and nuchal headache of subacute onset. Colour-duplex ultrasound disclosed bilateral low flow with a high resistance flow pattern in both vertebral arteries in the V2 segments, while the basilar artery had normal flow. CT angiography and MRI ruled out any ischaemic cerebral infarct and disclosed a persistent hypoglossal artery (PHA) originating from the left internal carotid artery (ICA). The patient was eventually treated for cervicobrachialgia. Persistent carotid-basilar anastomosis such as PHA may account for an atypical stroke pattern in carotid disease, aneurysms and arterovenous malformations. In retrospect, PHA is amendable to colour-Duplex investigation due to an abnormal ICA flow and a discrepancy between the vertebral and basilar flow patterns. Ultrasound investigation of the vertebrobasilar system remains a challenge as variants appear frequently; hypoplasia of the vertebral arteries should thus be confirmed using CT or MR angiography.

Bilateral vertebral artery occlusion with retrograde basilary flow in three cases of giant cell arteritis.

Vertebrobasilar ischaemia is a rare life-threatening complication in giant cell arteritis (GCA). We report three patients with bilateral vertebral artery occlusion. Neurovascular imaging, including CT-angiography, MR-angiography and colour-coded duplex sonography revealed flow reversal in the basilar artery as well as inflammation of the vertebral vessel wall. The first patient died from massive brainstem infarction, the other two patients survived the initial inflammatory phase of GCA. No stroke recurrence at 12 months' follow-up on warfarin and steroid treatment was observed. Bilateral distal vertebral artery occlusion and retrograde basilar artery flow persisted.Outcome in these patients is dependant on potent immunosuppression, concurrent atherosclerotic steno-occlusive disease and presence and/or rapid development of sufficient collateral pathways into the vertebrobasilar circulation. The identification of patients with high risk of ischaemia due to compromised vertebrobasilar flow may be important to select adjunct treatment to immunosuppression, such as anticoagulation in GCA.