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

Abstract

We present the case of a distal anterior inferior cerebellar artery (AICA) aneurysm masquerading as a cerebellopontine angle tumor in a 60-year-old righthanded man with previously undiagnosed polyarteritis nodosa (PAN). The patient presented with a 2-month history of progressive right-sided hearing loss, intermittent severe headache, and sudden onset of complete facial paralysis 3 weeks before admission. Magnetic resonance imaging, including postgadolinium images, showed a 1.2-cm heterogenously enhancing mass that slightly enlarged the right internal auditory canal. A right suboccipital craniotomy was performed, and a partially thrombosed fusiform AICA aneurysm was discovered just anterior to the VII/VIII nerve complex. The aneurysm was trapped and opened, and a thrombectomy was performed. Postoperatively, the patient experienced abdominal pain; liver function tests were abnormal. Investigation revealed a small retroperitoneal hemorrhage and aneurysms of the celiac axis and gastroduodenal arteries. Further investigation revealed an increased erythrocyte sedimentation rate, and a diagnosis of PAN was made. PAN is a well-identified factor in the genesis of peripheral vascular aneurysms. Aneurysms involving the hepatic, renal, coronary, pancreatic, and tibial arteries have been described. PAN is an extremely rare cause of intracranial aneurysm. Patients who present with aneurysms in unusual locations (e.g., distal AICA) should be investigated for vasculopathy and collagen vascular disorders.

Management of anterior inferior cerebellar artery aneurysms: an illustrative case and review of literature

“…24,31,40,51 In a series of more than 3500 saccular aneurysms treated surgically during a 16-year period, Gonzalez and colleagues 19 reported that a mere 34 (1.7%) aneurysms arose from the AICA. Of these, 21 became symptomatic with subarachnoid hemorrhage.…”

Compression of the Medulla Oblongata and Acute Respiratory Failure Caused by Rupture of a Thrombosed Large Aneurysm of the Anterior Inferior Cerebellar Artery -Case Report-

“…A few cases of thrombosed large AICA aneurysm have been reported, 1,6,7,11,13,16) including local association with acute hematoma. 6,16) One patient complained of sudden onset of occipital headache, nausea, and vomiting, 6) and the other patient suddenly developed facial numbness and headache.…”

“…[2][3][4][5][8][9][10][11][12]14,15,17) Progressive growth of an aneurysm of the AICA generally manifests as various cerebellopontine angle syndromes such as oculomotor nerve palsy, trigeminal sensory loss or neuralgia, sixth cranial nerve palsy, seventh cranial nerve palsy, vertigo, tinnitus, hearing loss, lower cranial nerve palsy, and ataxia. 1,6,7,10,11,13,14,16) Rapid deterioration of neurological symptoms generally indicates rupture of an aneurysm. Subarachnoid hemorrhage may subsequently cause dyspnea, arrhythmia, and death after these cerebellopontine angle syndromes occur.…”

Intracranial Aneurysms in Patients With CREST Syndrome -Two Case Reports-

“…MR angiography has detected increasing numbers of cerebral aneurysms in patients with collagen diseases, with a total of 48 cases reported up to September 2008, including 25 patients with systemic lupus erythematosus, 1,10,11,14,18-20,22,25,27,30-33,37,42, 43,52) 16 patients with polyarteritis nodosa, 2,8,9,24,28,29,35,36,41,44,45,[49][50][51] 5 patients with scleroderma, 3,17) and 2 patients with CREST syndrome. 38,56) To determine the specific features of cerebral aneurysm in patients with collagen diseases, we reviewed the 48 reported cases and identified the following four characteristics.…”