Multiple aneurysms of the PICA communicating artery: a case report

A case with unusual type of aneurysms in the distal posterior inferior cerebellar artery (PICA) is reported here. Though only two cases with a single aneurysm of the PICA communicating artery have been reported previously, the present case is the first one with multiple aneurysms in the PICA communicating artery. A 61-year-old woman with a sudden onset of severe headache, vomiting and unconsciousness was transferred to our hospital. CT scan revealed a hematoma in the fourth, third, and lateral ventricles, and a mild subarachnoid hemorrhage at the posterior fossa. Cerebral angiogram showed the right PICA supplying the hypoplastic left PICA territory through an anastomotic vessel. Two small aneurysms were seen at the tips of hairpin curves of an anastomotic vessel, "the PICA communicating artery". Suboccipital craniotomy was performed, and the ruptured aneurysm was clipped and the unruptured one was wrapped with cotton-sheet. After the operation, her clinical recovery went well and she was discharged on foot.     

Development of unusual collateral channel from the posterior meningeal artery after endovascular proximal occlusion of the posterior inferior cerebellar artery

A 38-year-old man presented with a dissecting aneurysm of the left proximal posterior inferior cerebellar artery (PICA) manifesting as Wallenberg's syndrome. The patient was treated by endovascular occlusion of the aneurysm and parent artery. Immediately after the treatment, the PICA territory was supplied by collateral circulation via the ipsilateral anterior inferior cerebellar artery. Seven days later, endogenous revascularization of the distal PICA territory had occurred via collateral circulation from the posterior meningeal artery (PMA). This unusual collateral circulation was thought to occur through a pre-existing anastomotic channel between the primitive vessels of the PICA and the PMA during subclinical hypoperfusion of the distal PICA territory. This unusual case demonstrates the potential for delayed development of collateral circulation from the PMA to the PICA territory.     

Embolization for aneurismal dilatation associated with ruptured dissecting anterior inferior cerebellar artery aneurysm with preservation of the parent artery: case report

We report a rare case of a ruptured dissecting anterior inferior cerebellar artery (AICA) aneurysm treated by endosaccular embolization with a Guglielmi detachable coil (GDC). An 85-year-old female presented with headache. Computed tomographic (CT) scan showed subarachnoid hemorrhage and intraventricular hemorrhage in the fourth ventricule. Cerebral angiography and 3D-CT angiography revealed an aneurysmal dilatation at the anterior pontine segment of the right AICA with a diagnosis of arterial dissection. The right posterior inferior cerebellar artery (PICA) was absent and the right AICA supplied the territory normally nourished by the right PICA. The aneurismal dilatation was occluded by endosacullar embolization with preservation of the AICA. The distal AICA aneurysm is rare and only seven cases treated with endovascular embolization have been reported. In these, six cases were treated by parent artery occlusion with coil and the subsequent three cases presented with ischemic complications. Only one case was treated by endosaccular embolization with GDC. To our knowledge, this is the second report of the distal AICA aneurysm treated by endosaccular embolization with GDC. Distal AICA aneurysms are briefly discussed while reviewing the literature.     

Posterior inferior cerebellar artery (PICA) aneurysm presenting with SAH and contralateral crural monoparesis: a case report.

A patient with contralateral monoparesis of the leg due to subarachnoid hemorrhage (SAH) from an aneurysm of the first posterior inferior cerebellar artery (PICA) segment is reported. The monoparesis may well be associated with the close anatomical relationships between the site of the aneurysm and the PICA blood supply of the corticospinal fibers to the contralateral leg.     

A "PICA communicating artery" aneurysm: case report.

We present an unusual case of an aneurysm of the distal posterior inferior cerebellar artery (PICA). The aneurysm was associated with a unilateral PICA that supplied both cerebellar hemispheres and arose from an anastomotic vessel to the contralateral circulation, a branch of the contralateral PICA. Such an aneurysm has not been reported previously. The associated of vascular anomalies with aneurysms of the PICA is discussed.     

Bilateral mirror posterior inferior cerebellar artery aneurysms: diagnostic caveat on catheter angiography

Only three definitive cases of bilateral mirror proximal posterior inferior cerebellar artery (PICA) aneurysms have ever been reported. A fourth example is presented where each PICA aneurysm remained angiographically occult on contralateral vertebral artery angiography despite retrograde filling of the parent vessel PICA. Implications for clinical practice are discussed.     

Distal aneurysm of the posterior inferior cerebellar artery--report of 3 cases

The incidence of posterior fossa aneurysm is reported to be 4-15% of all intracranial aneurysms in large series. Most aneurysms of the posterior inferior cerebellar artery (PICA) arise at the origin of the PICA. However, aneurysms of the distal part of the PICA have only rarely been described. This report presents three cases of distal PICA aneurysm with subarachnoid hemorrhage. Two aneurysms were located in the superior retrotonsillar segment of the PICA in two cases, and another was located in the tonsillohemispheric branch in one case. Obliteration of these aneurysms was comparatively easily done by bilateral suboccipital craniectomy. Computerized tomography (CT) was done in two cases. CT scan of the second case revealed a hematoma in the cerebellar vermis, and that of the third case revealed hemorrhage in the fourth and third ventricles. These findings seem to be common in subarachnoid hemorrhage of this lesion and may suggest the rupture of distal PICA aneurysm.     

Extracranial posterior inferior cerebellar artery aneurysm causing isolated intraventricular hemorrhage: a case report

The authors report the unusual case of an aneurysm arising on an extracranial loop of the left posterior inferior cerebellar artery (PICA). The computed tomographic scan showed an isolated hemorrhage in the lateral ventricles, and the lesion was recognized 1.5 cm below the foramen magnum at the level of the atlas. The literature concerning peripheral PICA aneurysms is reviewed and the clinical and radiological features of these lesions are discussed. A tendency for subarachnoid bleeding from distal PICA aneurysm ruptures to spread into the ventricular system is suggested. The diagnosis of distal PICA aneurysm should also be considered in cases of isolated intraventricular hemorrhage without obvious parenchymal or subarachnoid hemorrhage. The need for four-vessel angiography when studying patients suffering from a subarachnoid hemorrhage is stressed.     

Multiple,peripheral aneurysms of the anterior inferior cerebellar artery

Summary In this case report, a 49-year-old woman developed subarachnoid hemorrhage in the right cerebellopontine angle cistern and blood into the fourth ventricle from a ruptured peripheral aneurysm of the anterior inferior cerebellar artery (AICA) located at the meatal loop. Concomitantly, a contralateral peripheral aneurysm was found in the posterior inferior cerebellar artery (PICA). A second peripheral aneurysm, not identified by previous angiography, was found in the caudomedial branch of AICA. We describe this diagnostic dilemma, management, and review the clinical presentation and location of 84 other peripheral AICA aneurysms reported in the literature.     

Ruptured aneurysm at an anastomotic artery extending from the vertebral artery to the posterior inferior cerebellar artery: a case report

A 51-year-old hypertensive man presented with subarachnoid haemorrhage. He had a past history of cerebellar infarction due to occlusion of the right posterior inferior cerebellar artery (PICA) 4 years earlier. Digital subtraction angiography showed a saccular aneurysm above an arterial loop extending from the vertebral artery to the distal part of the PICA, reminiscent of peripheral PICA branches. We performed aneurysmal neck clipping with excellent outcome. Aneurysms at anastomotic arteries are extremely rare and can result from increased haemodynamic stress. We report the first case of a ruptured aneurysm at an anastomotic artery in the posterior circulation territory.     

Dissecting aneurysms of the vertebral artery: a management strategy

OBJECT: The authors present a retrospective analysis of their experience in the treatment of vertebral artery (VA) dissecting aneurysms and propose a management strategy for such aneurysms, with special emphasis on the most formidable VA dissecting aneurysms, which involve the origin of the posterior inferior cerebellar artery (PICA). METHODS: Since 1998, 18 patients with VA dissecting aneurysms, 11 of whom presented with subarachnoid hemorrhage (SAH), have been treated by endovascular surgery at the authors' institution. Obliteration of the entire segment of the dissected site with coils (internal trapping) was performed for aneurysms without involvement of the origin of the PICA (12 cases; among these the treatment-related morbidity rate was 16.7%). The treatment strategy applied to PICA-involved VA dissecting aneurysms presenting with SAH (three cases) included proximal occlusion of the parent artery followed by internal trapping of the aneurysm (one case), proximal occlusion of the parent artery followed by occipital artery (OA)-PICA bypass (one case), and two-staged internal trapping of the aneurysm involving double PICAs (one case). For PICA-involved VA dissecting aneurysms that were not associated with SAH at presentation (three cases), OA-PICA bypass was performed and followed by internal trapping of the aneurysm (two cases). In the remaining case in which a fetal-type posterior communicating artery was present, internal trapping was performed following successful balloon test occlusion (BTO). Overall, there was no sign of infarction in the PICA territory, despite complete occlusion of aneurysms involving the PICA. There was no recurrent bleeding or ischemic symptoms during the follow-up periods. The overall treatment-related morbidity rate for the VA dissecting aneurysms involving the PICA was 16.7%. CONCLUSIONS: Dissecting VA aneurysms that do not involve the PICA can be safely treated by internal trapping. For those lesions that do involve the PICA, a decision-making algorithm is advocated to maximize the efficacy of the treatment as well as to minimize the risks of treatment-related morbidity based on BTO.     

Peripheral aneurysms of the posterior inferior cerebellar artery

Nonmycotic peripheral posterior inferior cerebellar artery (PICA) aneurysms are rare. The authors report six cases of peripheral PICA aneurysm. Two of these are unusual; one was fusiform and another was a double aneurysm arising from the peripheral PICA. The previously reported 40 cases of peripheral PICA aneurysm are reviewed.     

Treatment of vertebral artery aneurysms with posterior inferior cerebellar artery-posterior inferior cerebellar artery anastomosis combined with parent artery occlusion

BACKGROUND: In patients with aneurysms that involve the origin of the posterior inferior cerebellar artery (PICA) and require occlusion of the vertebral artery (VA), revascularization of the PICA is commonly performed. We present six patients with dissecting VA aneurysms who underwent PICA-PICA anastomosis combined with parent artery occlusion. METHODS: After a lower lateral suboccipital craniectomy and partial resection of the jugular tubercle, anastomoses were performed in a side-to-side fashion at the posterior medullary segment of the PICA. The VA was subsequently occluded by clipping proximal and distal to the aneurysm, and the PICA was occluded by clipping distal to the aneurysm. RESULTS: Postoperative cerebral angiography demonstrated patency of the anastomosis and regression of the aneurysm in five of six patients. The remaining patient experienced hemorrhage from contralateral VA dissection and subsequently died. One patient experienced myopathy of the lower extremities secondary to intraoperative fixed board compression and developed permanent lower extremity muscular weakness. The remaining four cases experienced no new neurologic deficits. CONCLUSION: PICA-PICA anastomosis is a useful procedure for reconstruction of the PICA when parent vessel occlusion or trapping is necessary to exclude a VA aneurysm involving the origin of the PICA.     

Distal aneurysms of the superior cerebellar artery and posterior inferior cerebellar artery feeding an associated arteriovenous malformation: case report.

The authors report a case of two distal aneurysms of the cerebellar arteries, one arising from the vermian branch of the posterior inferior cerebellar artery, the other arising from the hemispheric branch of the superior cerebellar artery, and both feeding an associated arteriovenous malformation (AVM). The aneurysm of the distal posterior inferior cerebellar artery was considered the source of a cerebellar hemorrhage because of the location of a hematoma in the cerebellar vermis. The life-threatening hematoma was evacuated in an emergency operation 6 hours after the acute onset of symptoms. The cerebellar aneurysms and the AVM were clipped or extirpated successfully after the patient's condition improved. The association of two rare types of aneurysms with an AVM strongly supports the theory that increased hemodynamic stress derived from the AVM plays an important role in aneurysm formation. The authors think that one should operate on the symptomatic lesion first or both the aneurysm and the AVM in the same operative procedure.     

Aneurysm of the distal posterior inferior cerebellar artery originating from the extracranial and extradural vertebral artery

A 42-year-old woman presented with a ruptured aneurysm of the distal posterior inferior cerebellar artery (PICA), which had a rare extracranial and extradural origin. Medial suboccipital craniectomy and C-1 laminectomy were performed. The aneurysm had adhered to the right cerebellar tonsil, but was successfully clipped without difficulty. Intraoperatively, the PICA origin was recognized in the extracranial and extradural space between the dorsal roots of the C-1 and C-2 nerves. The origin of the PICA from the vertebral artery (VA) may occur at any portion of the VA from the site of penetration of the dura to the vertebrobasilar junction, but an extradural origin is uncommon. A ruptured aneurysm of the PICA branching from the VA at a site proximal to the vertebrobasilar junction and below the foramen magnum may be overlooked by three-vessel angiography if the contrast medium cannot reflux to the contralateral PICA origin.     

Peripheral PICA aneurysm. Case report

One case of aneurysm of the right distal posterior inferior cerebellar artery (PICA), arising from the telo-velo tonsillary segment, is reported; the patient, a 73 years-old woman, was successfully treated by clipping procedure. Few similar cases are reported in literature. Among all intracranial aneurysms, PICA aneurysms account for 0.5-0.7%; most of them arise from vertebro-basilar junction, while only 72 distal PICA aneurysms are reported in literature, till now, with complete anatomo-radiological study. We recommend four vessel angiography because these aneurysms are likely to be missed. When determining the surgical approach it is important to know from which segment the aneurysm arises.     

Subarachnoid hemorrhage caused by ruptured intracranial fusiform aneurysm associated with microscopic polyangiitis

A 44-year-old woman with microscopic polyangiitis (MPA) presented with a ruptured cerebral aneurysm. She was admitted to our hospital for further examination of progressive renal failure. She was found lying on the ward floor. Computed tomography showed subarachnoid hemorrhage, and digital subtraction angiography revealed a saccular-like aneurysm arising from the right distal posterior inferior cerebellar artery (PICA) at the non-branching site. We performed neck clipping of the right distal PICA aneurysm, which recurred 5 days after the operation. Second angiography demonstrated a right distal PICA aneurysm just above the site of the clip. Therefore, we performed trapping of the affected lesion with emergent bypass of the contralateral occipital artery to the ipsilateral PICA. Her postoperative course was uneventful until she coughed up blood and had gross hematuria 3 days after the second surgery. Histological examination of a renal biopsy specimen revealed crescentic glomerulonephritis. MPA was diagnosed on the basis of the cardinal symptoms, including progressive glomerular nephritis and the lung abnormality, as well as the presence of myeloperoxidase-antineutrophil cytoplasmic antibodies. After intensive treatment, she was discharged for rehabilitation without neurological deficit. MPA commonly affects small-sized vessels mainly in the kidneys and lungs and may lead to crescentic glomerulonephritis and pulmonary hemorrhage. MPA is rarely associated with aneurysms of medium-sized muscular vessels. Cerebral aneurysm is extremely rare in patients with MPA, but rupture of an intracranial fusiform aneurysm can be lethal, so screening of the intracranial vessels should be performed by magnetic resonance imaging in patients with MPA.     

Vertebral dissecting aneurysm treated with trapping and bilateral posterior inferior cerebellar artery side-to side anastomosis; case report

A case is reported of ruptured dissecting aneurysm of the intracranial vertebral artery (VA) operated on with VA trapping and bilateral posterior inferior cerebellar artery (PICA) side-to-side anastomosis. A 42-year-old male suddenly developed severe headache and vomiting. On admission, 3 hours later, he was in a state of moderate confusion (Japan Coma Scale 3) and had neck stiffness. Computed tomography (CT) revealed diffuse subarachnoid hemorrhage, especially thick in the posterior fossa with right side dominance. Right vertebral angiography disclosed a fusiform dilatation with proximal narrowing of the right VA which originated just proximal to the VA-PICA junction. Lateral suboccipital craniectomy was undertaken with the patient in a left park bench position. Right VA was dilated and discolored black, and right PICA arose from the proximal portion of this aneurysmal dilatation. Since it was impossible to clip the VA distal to the PICA for the proximal clip-occlusion, the VA including the VA-PICA junction was trapped. Considering the risk of developing infarction at the PICA territory, bilateral PICA was anastomosed at their posterior medullary segment in a side-to-side fashion because the occipital artery (OA) had been cut at the skin incision and could not be used for the OA-PICA anastomosis. The postoperative course was benign, but a mild lateral medullary syndrome developed. CT revealed no abnormal low density area and left vertebral angiography demonstrated the patency of the bypass. Thereafter, the deficit subsided gradually and the patient was discharged. He is presently working without neurological deficit.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intraventricular hemorrhage due to aneurysms of the distal posterior inferior cerebellar artery. Report of three cases

Three cases of ruptured aneurysm of the distal posterior inferior cerebellar artery (PICA) presenting with isolated intraventricular hematoma are reported. All of the aneurysms originated from the lateral medullary segment of the PICA and ruptured into the lateral recess of the fourth ventricle. The diagnosis of distal PICA aneurysm should be considered if isolated intraventricular hematoma is found without obvious parenchymal hemorrhage or subarachnoid blood in the basal cisterns. Complete vertebral arteriography is a requisite for the recognition of this condition. The outcome in patients with these aneurysms should be good if surgical repair is performed before rebleeding occurs.     

A case of a ruptured pseudoaneurysm arising from the distal part of the posterior inferior cerebellar artery

We report a rare case of a pseudoaneurysm arising from the distal part of the posterior inferior cerebellar artery (PICA) and which was associated with intraventricular hemorrhages. A 48-year-old female had sudden onset of severe headache and vomiting, and was admitted in a semicomatous state to our hospital. Initial CT scan showed ventricular hematomas resulting in acute hydrocephalus, but no obvious parenchymal or subarachnoid hemorrhage. Ventricular drainage was carried out. Subsequently, cerebral angiography was performed, but neither, an aneurysm nor other vascular abnormality was detected. 50 days after admission, MRI revealed a homogenous and well-circumscribed hypointense mass (12 mm in diameter) in the right cerebellar tonsil, suggesting the presence of hemosiderin. 60 days after the onset, the second angiography showed an aneurysmal shadow arising from the distal part of the PICA. An aneurysmal clipping was performed via the suboccipital approach. A thrombosed aneurysm was identified in the right tonsil. At the time of the operation, we confirmed that the part of the PICA around the aneurysm was intact with neither branching nor discoloration. Histological examination revealed that elastic fiber was not identified in the aneurysmal wall, and the aneurysm was diagnosed as a pseudoaneurysm. Histories of trauma or infection, which may have induced the cerebral pseudoaneurysm, were not obtained by interview.