Carotid Artery Dissection-Related Intracranial Aneurysm Development

BACKGROUND AND IMPORTANCE: We analyzed the physiopathology of the association between cervical artery dissections (CADs), intracranial aneurysms (IAs), and aneurysmal subarachnoid hemorrhage. CLINICAL PRESENTATION: A 43-year-old woman presented with diffuse subarachnoid hemorrhage (Fisher 3; Hunt-Hess 1). computed tomography angiography revealed a cervical internal carotid artery dissection and 2 IAs: right paraclinoid and right posterior communicating artery. The patient underwent surgical clipping of the 2 aneurysms. CAD was managed conservatively. Postoperative course was initially uneventful. After 24 hours, digital subtraction angiography (DSA) documented the exclusion of the aneurysms and an improvement of the CAD. After 3 days, the patient's neurological condition suddenly worsened; CT scan documented a subarachnoid rebleeding (Hunt-Hess 4) and DSA revealed the recurrence of CAD and a new right internal carotid artery aneurysm. The patient underwent clipping of the new aneurysm and decompressive craniectomy because of severe brain swelling. Postoperative neurological conditions remained poor. DSA showed the exclusion of the aneurysms and improvement of CAD. Three days later, CT scan performed after a sudden raise in intracranial pressure documented a wide intracerebral hematoma. Computed tomography angiography did not show new vascular malformations. Surgical removal of the hematoma was performed, but poor neurological conditions persisted. CONCLUSION: CAD-related hemodynamic changes may play a role in the development of IAs. The presence of IAs must be screened carefully in case of CAD, because the dynamic behavior of CAD definitively increases the risk of IA formation, enlargement, and rupture.