Rupture aneurysm of the distal anterior inferior cerebellar artery (AICA) is extremely rare with an incidence of 0.03-0.5% of all intracranial aneurysms1. We are reporting a case of ruptured dissecting distal AICA aneurysm with spontaneous resolution. Isolated acute vestibular syndrome remains a diagnostic challenge in the emergency department and the initial approach should include the identification of a central or peripheral etiology2 .

A 42-year-old male patient developed sudden hearing loss in the right ear and vertigo. He also complained for 12 days of feeling very severe headaches, sometimes feeling nausea and vomiting, then taken to the hospital. On examination in getting high blood pressure accompanied by positive neck stiffness and down beat nystagmus. On CT Angiography, aneurysm is accompanied by rupture of the right anterior-inferior cerebellar artery.

Anterior inferior cerebellar artery (AICA) usually arises from the caudal third of the basilar artery and supplies the inner ear, facial and vestibulocochlea nerves, lateral pons, middle cerebellar peduncle and anterior cerebellum. Rupture Aneurysms of the anterior inferior cerebellar artery (AICA) are relatively rare among intracranial aneurysms. They can occur in 1 of 3 regions of the AICA: 1) craniocaudal (high or low riding), 2) mediolateral-premeatal (proximal), and 3) meatal-postmeatal (distal)3. Patients with distal AICA dissecting aneurysms may present symptoms and signs of typical SAH, with sudden severe headache, meningismus, nausea, vomiting, photophobia, and/or coma. More localizing presentations may be seen, especially in larger aneurysms with mass effect, tinnitus, hearing loss, vertigo, gait ataxia, diplopia, facial paresis and lower cranial nerve palsies4. Figure 1

Peripheral AICA ruptured dissecting aneurysm is a very rare disease and little information is available regarding its management. Parent artery occlusion may be proposed as a therapeutic alternative. When performing the occlusion by superselective embolization an excellent anatomic result and clinical outcome can be achieved.

Hancock J. H. Millar J. S. Spontaneous dissection of the anterior inferior cerebellar artery Neuroradiology 2000 42 7 535 538 0028-3940, 1432-1920 10.1007/s002340000324 Springer Science and Business Media LLC https://dx.doi.org/10.1007/s002340000324 Singh Sumeet Mittal RS Purohit Devendra Shekhawat Jetendra Spontaneous resolution of ruptured dissecting anterior inferior cerebellar artery aneurysm: A rare case report Asian Journal of Neurosurgery 2017 12 3 570 570 1793-5482 10.4103/1793-5482.145561 Medknow https://dx.doi.org/10.4103/1793-5482.145561 Rodríguez-Hernández Ana Distal aneurysms of intracranial arteries: application of numerical nomenclature, predilection for cerebellar arteries, and results of surgical management World neurosurgery 2013 80 103 112 Wegmann-Vicuña Ricardo Muñoz-Hernández Diana E. Gallegos-Constantino Vivian Domínguez-Echavarri Pablo Irimia-Sieira Pablo Pérez-Fernández Nicolás Acute vestibular syndrome with down-beat nystagmus as a sole clinical presentation in AICA transient ischemic attack with an uncommon clinical course Acta Oto-Laryngologica Case Reports 2017 2 1 131 136 2377-2484 10.1080/23772484.2017.1367255 Informa UK Limited https://dx.doi.org/10.1080/23772484.2017.1367255