Distal posterior inferior cerebellar artery aneurysm: case report

Abstract

-The majority of posterior inferior cerebellar artery (PICA) aneurysms are usually found on the bifurcation of the vertebral artery (VA) -PICA junction. Aneurysms arising from more peripheral PICA segments named distal PICA aneurysm are uncommon. The major clinical manifestation is that of an intracranial bleeding and the site of hemorrhage is related to the PICA segment originating the aneurysm. Lesions originating from distal PICA segments, particularly those arising from the telovelotonsillar segment, are associated with hemorrhage extending into the ventricular system, mainly the IV ventricle. A case of a 50-year-old woman with sudden headaches and vomiting, and intraventricular hemorrhage (four ventricles) caused by an aneurysm of the telovelotonsillar segment of the PICA, is presented. No signs of subarachnoidal hemorrhage were found in the computerized tomography. The aneurysm was clipped and the patient presented a favorable outcome. Anatomical aspects and clinical series are reviewed.KEY WORDS: intracranial aneurysm, posterior circulation, posterior inferior cerebellar artery, subarachnoid hemorrhage.Aneurisma da artéria cerebelar posterior e inferior distal: relato de caso RESUMO -A maioria dos aneurismas da artéria cerebelar posterior inferior (PICA) é geralmente encontrada na junção artéria vertebral (VA) -PICA. Aneurismas originando-se nos segmentos mais distais da PICA são considerados raros. A manifestação clínica em geral por hemorragia intracraniana, e o local desta está relacionado ao segmento que origina o aneurisma. Lesões localizadas em segmentos mais distais da PICA, em especial os originados do segmento telovelotonsilar, estão associados a hemorragias no sistema ventricular, particularmente no quarto ventrículo. Relatamos o caso de mulher de 50 anos de idade que desenvolveu quadro de cefaléia súbita e vômitos, com hemorragia nos quatro ventrículos, causada por ruptura de aneurisma localizado no segmento telovelotonsilar da PICA. Não havia sinais de hemorragia subaracnói-dea na tomografia computadorizada de crânio. O aneurisma foi clipado e a paciente apresentou evolução favorável. Aspectos anatômicos e outras séries são revisados. PALAVRAS-CHAVE: aneurismas intracranianos, circulação posterior, artéria cerebelar posterior inferior, hemorragia subaracnóidea.Aneurysms of the posterior inferior cerebellar artery (PICA) are uncommon, complaining approximately 0.49% of all intracranial aneurysms 1 and 20% of the posterior fossa aneurysms 2 . The majority of them are localized at the vertebral artery (VA) PI-CA junction [3][4][5] . There are few large series of distal PICA aneurysms [6][7] , with no more than 26 cases. These lesions are very rare, their anatomy is complex and the clinical features, outcome and treatment are not well understood. We report the case of a 50-year-old woman with intraventricular hemorrhage caused by hemorrhage of an aneurysm at the telovelotonsilar portion of the right PICA. The anatomy and clinical series are reviewed.Anatomy -The PICA has the most complex,...

Coiling for a saccular aneurysm on the caudal channel in double origin of the posterior inferior cerebellar artery

“…30 In addition, although intracranial aneurysms usually arise from arterial bifurcations, many distal PICA aneurysms are unrelated to the branching. 15,29 Intracranial aneurysms associated with a DOPICA have been previously reported. 2,3 Lesley et al concluded that the DOPICA has an increased association with intracranial aneurysmal disease and might represent a risk factor for subsequent development of intracranial aneurysms.…”

“…The PICA is the largest branch of the VA, generally arising 10 mm superior to the foramen magnum, starting from the posterolateral side of the VA and running from the medulla oblongata to the posterior side. 14 In most cases (85-95%), the PICA arises from the intracranial portion of the VA. 15 Beginning from the proximal side, the PICA is divided into five segments (anterior medullary, lateral medullary, tonsillomedullary, telovelar tonsillar and cortical). 16 The PICA shows many variations in morphology and course.…”

“…In general, PICA aneurysms are uncommon, representing approximately 0.5–3.0% of all aneurysms. 22,28 The majority are localised to the VA–PICA junction, 15,28 and distal PICA aneurysms are considered to represent <30% of all PICA aneurysms. 29 Other reports have stated that distal PICA aneurysms represent 0.5–1% of intracranial aneurysms, 30,31 suggesting that aneurysms arising from the distal portion of the PICA are rare, and that the most common location of a distal PICA aneurysm is the telovelar tonsillar segment.…”

“…30 In addition, although intracranial aneurysms usually arise from arterial bifurcations, many distal PICA aneurysms are unrelated to the branching. 15,29…”

Distal posterior cerebellar artery aneurysm: Case report

“…Considering the way of spreading, she vascularizes caudal medulla oblongata, cerebellar tonziles, lowejr portion of cerebellar hemisphere and vermis and plexus horoideus of IV ventricle. 4,5,7 Critical surgical points on the occasion of preparation of aneurysms of this flow are n. IX, n. X and n. XII, whose little traction brings to difficult problems of disfagy, disartry type and potential life endangering aspiration.…”