Angiographic Demonstration of Anterior Inferior Cerebellar Artery Aneurysm By Use of the Base View

Abstract

Involvement of the anterior inferior cerebellar artery is the rarest form of posterior fossa aneurysm. A case is presented in which such a lesion was demonstrated angiographically by use of the submental-vertex view.A NEURYSMS of the anterior inferior cerebellar artery (AICA) ..t1.. are extremely rare; only 2 were discovered in a series of 7,933 intracranial aneurysms (4). Preoperative angiographic demonstration of the lesion has been described only once previously (8). The purpose of this report is to describe a second case and stress the importance of the base view in the angiographic localization of posterior fossa aneurysms. CASE REPORT R. B., a 41-year-old Caucasian woman had been in good health until the day of admission to Barnes Hospital. Her husband returned from work to find her semicomatose in bed with evidence of recent vomiting. At a local hospital a lumbar puncture examination revealed an opening pressure of 300 mm Hg and grossly bloody cerebrospinal fluid. NeuroradiologyOn admission, fundoscopic examination revealed bilateral papilledema with flame-shape hemorrhages. There was marked nucchal rigidity and the patient was lethargic and confused. Blood pressure was elevated to 170/90. Extensive right-side cranial nerve involvement was noted, with the right sixth through twelfth nerves affected. The deep tendon reflexes were diffusely hyperactive. Electrolytes and blood profile were normal as were the chest and skull radiographs.Right brachial angiography was performed with simultaneous anteroposterior (Fig. 1) and lateral (Fig. 2) filming. These views revealed an aneurysm lateral and posterior to the right vertebral artery but its origin could not be determined with certainty. A submental-vertex view was then obtained (Fig. 3), but the aneurysm was crossed by both the right anterior inferior cerebellar artery (AICA) and right posterior inferior cerebellar artery (PICA). For this reason, left brachial angiography was performed in the submental-vertex position (Fig. 4). Filling of the aneurysm was from the basilar artery and right AICA with no filling of the right PICA. Right cerebellar craniotomy was performed and a 0.5 X 0.3 X 0.5-cm aneurysm was discovered immediately below the origins of the right ninth and tenth cranial nerves with a thick dot surrounding the eleventh and twelfth nerves. The aneurysm was excised and the right AICA dipped, but not all of the adherent dot could be removed.A postoperative angiogram showed failure of the previous aneurysm to fill, with opacification of only the proximal 8 mm of the right AICA. Occlusion of the vessel at the point of dipping with retrograde propagation of clot was considered present. DISCUSSIONThe incidence of posterior fossa aneurysms has been reported as 8-12% of all intracranial aneurysms (l, 5, 8). Involvement of the AICA is the rarest of all posterior fossa aneurysms (1). Locksley's review of 7,933 aneurysms in 5,484 patients (4) in a cooperative study revealed only 2 in- Fig. 1. Anteroposterior view of the right brachial angiogram demonstrates a l...

Distal Anterior Inferior Cerebellar Artery Aneurysm Masquerading as a Cerebellopontine Angle Tumor: Case Report and Review of Literature

“…18 The overall management of distal AICA aneurysms includes wrapping, proximal occlusion, trapping, intravascular embolization with coils, and direct surgical clipping. 4,7,8,10,[19][20][21][22][23][24][25][26] In a review of the literature, no single intervention proved more successful than any other in reversing preoperative deficits or preventing postoperative deterioration in the function of cranial nerves VII and VIII. The limited available information suggests a very low incidence of ischemic complications related to trapping distal AICA aneurysms close to the IAC (particularly if seventh and eighth cranial nerve dysfunction is present preoperatively).…”

Distal anterior inferior cerebellar artery aneurysms

“…41 Thorough evaluation of these lesions with neuroimaging should include CT scanning (in cases of acute hemorrhage), MR imaging, MR angiography, and digital subtraction angiography if a vascular lesion is suspected. Repeated digital subtraction angiography with special views 18,27,40 and/or CT angiography may be helpful in selected cases as well. 16 Microsurgical intervention for either clip ligation or trap- ping with resection has been the procedure of choice.…”

Aneurysm of the internal auditory artery: Our experience and review of the literature

“…Most of the distal aneurysms of AICA, excluding aneurysms of BA-AICA junction, caused subarachnoid haemorrhage [2, 4, 7, 8, 10, 12, 13-17, 19-21, 23, 25, 26-30, 32-34, 36, 38, Present study], sometimes followed by cerebellar [8], medullary [8] and lower cranial nerve signs [16,20], with [2,4,7,12,13,15,17,20,21,23,25,28,29,[32][33][34]36 syndromes of cerebello-pontine angle lesions, caused 8th [2,4,7,12,15,17,20,21,23,25,28,29,[32][33][34], 7th [2,4,7,12,13,15,17,20,21,25,29,32,…”