- Department of Neurosurgery, Kinki University, Faculty of Medicine, Osaka, Japan
Department of Neurosurgery, Kinki University, Faculty of Medicine, Osaka, Japan
DOI:10.4103/2152-7806.158206Copyright: © 2015 Kubota H. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
How to cite this article: Kubota H, Sanada Y, Nagatsuka K, Kato A. A case of angiographically occult, distal small anterior inferior cerebellar artery aneurysm. Surg Neurol Int 04-Jun-2015;6:97
How to cite this URL: Kubota H, Sanada Y, Nagatsuka K, Kato A. A case of angiographically occult, distal small anterior inferior cerebellar artery aneurysm. Surg Neurol Int 04-Jun-2015;6:97. Available from: http://surgicalneurologyint.com/surgicalint_articles/case-angiographically-occult-distal-small-anterior-inferior/
Background:A small aneurysm at an unusual location, such as a distal anterior inferior cerebellar artery (AICA) aneurysm, may conceal as a computed tomography angiography (CTA) and digital subtraction angiography (DSA)-occult aneurysm.
Case Description:We herein present the case of a patient suffering from a subarachnoid hemorrhage (SAH) with two aneurysms in which the AICA aneurysm was negative by CTA and DSA. CTA demonstrated a right anterior choroidal artery aneurysm, which was revealed to be an unruptured aneurysm after surgical exploration. A small distal AICA aneurysm was detected by 3D rotational angiography (3DRA). The patient fully recovered except for left-side hearing loss four months after the second operation.
Conclusion:We recommend a meticulous diagnosis by 3DRA in patients with SAH in which the distribution is not coincident with a typical aneurysmal location.
Keywords: Distal anterior inferior cerebellar aneurysm, diagnosis, subarachnoid hemorrhage, 3D rotational angiography, 3D computed tomography angiography
A distal anterior inferior cerebellar artery (AICA) aneurysm is relatively rare, and is estimated to comprise approximately 1–2% of all intracranial aneurysms.[
A 71-year-old male was transferred to our hospital with severe headache. A computed tomography (CT) scan showed subarachnoid hemorrhage (SAH), the distribution of which was dominant in the left side and relatively localized in the posterior fossa [
(a) A CT scan taken on admission showed a subarachnoid hemorrhage (SAH) in the left cerebellopontine cistern, ambient cistern and sylvian fissure. (b) The 3D computed tomographic angiography depicted the right anterior choroidal artery (AChA) aneurysm (arrow). (c) Magnetic resonance fluid attenuated inversion recovery images demonstrated that the SAH was continuing from the AChA aneurysm (arrow head); L: Left, R: Right
(a) The 3D rotational angiography showed a small aneurysm (arrow head) on the left anterior inferior cerebellar artery (AICA). (b) The lateral view of the 2D digital subtraction angiogram failed to depict any aneurysms. (c) An intraoperative photograph. (d) Neck clipping of the aneurysm; VIII: Acoustic nerve, IAA: Internal auditory artery
Although the incidence of distal AICA aneurysms varies,[
The diagnosis for a small peripheral aneurysm commonly requires careful investigation during radiological examinations. Especially if the aneurysm is small (<3 mm), the aneurysm may be defined as an angiographic occult aneurysm, or as a CTA-occult aneurysm.[
3DRA is desirable to detect a small peripheral aneurysm when the distribution of SAH is not in agreement with the aneurysmal location. A distal AICA aneurysm is a relatively rare aneurysm, but such a possibility has to be taken into consideration when making a differential diagnosis, especially if the SAH is observed in the posterior fossa.
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