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.     

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.     

Clip reconstruction for a case of peripheral posterior inferior cerebellar artery aneurysm: case report.

The authors report an unusual surgical treatment for an aneurysm on the left peripheral posterior inferior cerebellar artery (PICA). The computed tomographic scan showed subarachnoid haemorrhage and a haematoma in the left cerebellar region close to the fourth ventricle. The 3D CT angiography demonstrated an aneurysm on the left peripheral PICA which was confirmed on four-vessel angiography. The aneurysm was approached through a posterior suboccipital craniotomy and the PICA was reconstructed with multiple clips. The literature concerning peripheral PICA aneurysms and their treatment is reviewed and discussed.     

Ruptured aneurysm of a posterior inferior cerebellar artery communicating artery. Case report and histological findings

A hypertensive 60-year-old man presented with a rare aneurysm arising from the posterior inferior cerebellar artery (PICA) communicating artery, manifesting as subarachnoid hemorrhage with intraventricular hemorrhage. Angiography showed a small aneurysm arising from a fine and tortuous artery interconnecting the bilateral vermian branches of distal PICAs. The right PICA was absent and its vermian territory was supplied by the left PICA through this communicating artery. The right anterior inferior cerebellar artery was also connected to the vermian branch of the right PICA. At surgery, a reddish and apparent fusiform aneurysm was noted at the top of the arterial loop under the cerebellar vermis. Microsurgical trapping and removal of the aneurysm was performed without complication. Histological examination demonstrated typical findings of a true aneurysm. Only four previous cases of aneurysm of the communicating artery between the bilateral distal PICAs have been reported. In all five reported cases including ours, the PICA communicating artery contributed to the collateral blood supply of the contralateral vermian territory based on vascular anomalies. Hemodynamic stress and congenital vulnerability may have caused this aneurysm. Trapping is suitable to treat this precarious aneurysm if other collateral vessels supply the contralateral vermian territory.     

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.     

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.     

Dissecting Aneurysm of the Peripheral Posterior Inferior Cerebellar Artery

Dissecting aneurysms of intracranial posterior circulation have recently been shown to be less uncommon than previously thought. However, those involving the posterior inferior cerebellar artery (PICA) and not vertebral artery at all are extremely rare. We report here a case of a patient with a dissecting aneurysm of the lateral medullary segment of PICA which presented as subarachnoid haemorrhage. The aneurysm was treated by trapping surgery and the distant PICA was anastomosed to the occipital artery. The patient showed a slight ataxia immediately after surgery but recovered fully. Recovery from immediately postoperative cerebellar symptoms due to intra-operative ischemia seemed to be due largely to recovery of flow in the region of cortical branches of PICA.     

Posterior inferior to posterior inferior cerebellar artery anastomosis combined with trapping for vertebral artery aneurysm. Case report

A case is presented in which a giant intracranial vertebral artery aneurysm gave rise to an associated ipsilateral posterior inferior cerebellar artery (PICA) from its waist. Proximal vertebral artery ligation at C-1 was achieved. The aneurysm filled from the opposite vertebrobasilar junction. Direct intracranial trapping of the right vertebral aneurysm was followed by successful anastomosis of the proximally sectioned right PICA to the adjacent left PICA in an end-to-end fashion.     

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.     

A growing aneurysm of the posterior inferior cerebellar artery complicated with cerebellar infarction: A case report

Introduction and importanceHereby we describe an instructive patient with cerebellar infarction and a growing aneurysm at the posterior inferior cerebellar artery (PICA), which was not a true cause of infarction.Case presentationA 50-year-old female presented with dizziness and posterior neck pain at our hospital (Mitaka city, Tokyo, Japan). Diffusion weighted magnetic resonance (MR) images showed cerebellar infarction in the left PICA territory and MR angiography study showed an aneurysm at the origin of the left PICA, which grew in 2 weeks. Since we considered cerebellar infarction was caused by thrombosis from the aneurysm, trapping of the PICA and occipital artery-PICA bypass was performed to prevent recurrent cerebellar infarction and rupture of the aneurysm by neurosurgeons. During the operation, dissection was observed at the distal PICA, which was diagnosed to be the true cause of cerebellar infarction. By the follow-up for 12 months at an outpatient, there was no recurrence of cerebral infarction.Clinical discussionA specimen of the artery showing the findings of dissection was not obtained, and the pathological diagnosis could not be made. It would be controversial whether a surgical procedure presented here was the most optimal.ConclusionThis is a first reported case of growing aneurysms and cerebral infarction due to arterial dissection. Even if cerebral infarction is accompanied by growing aneurysms, arterial dissection should be included in the differential diagnoses of a cause of infarction. Posterior cervical pain can be a clue for early appropriate diagnosis in such a case.     

Successful clipping of a distal posterior inferior cerebellar artery aneurysm located on the anterior surface of the medulla oblongata--case report

A 55-year-old male presented with a ruptured distal posterior inferior cerebellar artery (PICA) aneurysm manifesting as subarachnoid hemorrhage. Angiography demonstrated a saccular aneurysm arising from the lateral medullary segment of the left PICA and located on the medial side of the left vertebral artery (VA) and the anterior surface of the medulla oblongata. A transcondylar fossa approach was used to ensure a sufficient operating field and to obtain adequate visualization of the aneurysm, the parent artery, and the perforating arteries to the medulla oblongata. The aneurysm dome protruded medially at the hairpin curve, and was located on the medial side of the left VA and on the anterior surface of the medulla oblongata. There was no vessel branches in the vicinity of the aneurysm. The aneurysm was successfully clipped with minimum retraction of the cerebellar hemisphere and medulla oblongata. Distal PICA aneurysms can be located at various sites in the posterior fossa. The exact location of the aneurysm must be established to select the best surgical approach.     

Aneurysm of the distal posteroinferior cerebellar artery of extracranial origin: case report

OBJECTIVE AND IMPORTANCE: We describe a very rare case involving a ruptured intracranial aneurysm at the distal posteroinferior cerebellar artery (PICA) branching from the extracranial vertebral artery. CLINICAL PRESENTATION: A 53-year-old woman experienced the sudden onset of a severe occipital headache and vomiting. Computed tomographic scanning revealed subarachnoid and intraventricular hemorrhage. Cerebral angiography of the left vertebral artery demonstrated the left PICA branching from the extracranial segment of the extracranial vertebral artery at the level of C2; a saccular aneurysm arose from the intracranial portion of the distal PICA. INTERVENTION: Via the transcondylar approach, we were able to obtain adequate visualization without retracting important structures. To avoid injury to the anomalous PICA, the aneurysm was clipped. CONCLUSION: Only four other cases of a distal aneurysm of the PICA branching from the extracranial vertebral artery have been reported in the literature. In all cases, the aneurysm originated at the intradural extracranial portion of the PICA. To our knowledge, the case presented here is the first report of a ruptured aneurysm at the level of the intracranial portion of the PICA branching from the extracranial segment of the vertebral artery.     

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.     

Bilateral anomalous posterior inferior cerebellar artery-anterior inferior cerebellar artery anastomotic arteries associated with a ruptured cerebral aneurysm--case report

A 50-year-old man presented with subarachnoid hemorrhage from a ruptured cerebral aneurysm arising from a left posterior inferior cerebellar artery (PICA)-anterior inferior cerebellar artery anastomotic artery manifesting as severe headache, obtundation, and quadriplegia. Conventional and three-dimensional digital subtraction angiography showed that the anastomotic complex was present bilaterally and both vertebral arteries terminated at the origin of the PICA. The identification of this anomalous vascular network allowed coil embolization of the broad-based aneurysm with occlusion of the parent artery. The patient had residual moderate disturbance of consciousness and quadriplegia before transfer for rehabilitation.     

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.     

Subarachnoid hemorrhage caused by posterior inferior cerebellar artery aneurysm with an anomalous course of the atlantoaxial segment of the vertebral artery. Case report and review of literature

Various anatomical courses of the vertebral artery (VA) and posterior inferior cerebellar artery (PICA) have been described. The authors present a unique case of a subarachnoid hemorrhage resulting from an aneurysm in a patient with an anatomical variation of the extracranial portion of the VA and cervical origin of the PICA. The surgical implications of this variant are discussed, and the pertinent literature reviewed. Subarachnoid hemorrhage caused by rupture of a PICA aneurysm is reported for the first time in association with a rare variation of the course of the VA.     

Ruptured aneurysm at the choroidal branch of the posterior inferior cerebellar artery: a case report and review of the literature

BACKGROUND: The authors present a rare case of a ruptured aneurysm at the choroidal branch of the posterior inferior cerebellar artery (PICA). CASE DESCRIPTION: A 77-year-old female was admitted to our institute because of sudden onset of severe headache and vomiting. Radiologic examination revealed intraventricular hemorrhage caused by rupture of the aneurysm at the choroidal branch of the PICA. The fusiform aneurysm was resected after ligation via a midline suboccipital approach. CONCLUSIONS: The conclusions drawn from this experience and a review of the literature include the following: (1) the aneurysm at the branch of the PICA is frequently associated with anomalies of the vascular structure, particularly in hypoplasty of the contralateral PICA; (2) hemodynamic stress is speculated to be a causative factor of these lesions; (3) cases with hypoplasty of the contralateral PICA have the possibility of developing nonmycotic peripheral aneurysms at the branch of the PICA; (4) these aneurysms should be managed immediately because of the high risk of rebleeding.     

Dissecting aneurysm of the posterior inferior cerebellar artery--studied by serial angiography]

We report the case of a 34-year-old male with cerebellar hemorrhagic infarction caused by a dissecting aneurysm of the left posterior inferior cerebellar artery (PICA). The patient suffered from a headache and vomiting for two days and was transferred to our hospital with sudden deterioration of consciousness. On admission, he was semicomatose. A CT scan revealed hemorrhagic infarction in the left cerebellum and upward herniation. The emergency operation for posterior fossa decompression was performed. Postoperatively, his consciousness level improved promptly and he had no neurological deficits except for slight gait disturbance. The first vertebral angiography was performed on Day 27. It showed a sausage-like dissecting aneurysm of the left distal PICA. We planned conservative therapy with careful observation because of there being no indication for an operation. Serial angiography was performed and demonstrated the regression of the dissecting aneurysm on Day 258. Dissecting aneurysms of the distal PICA are rare and their natural history is not well understood. Conservative therapy for vertebrobasilar dissecting aneurysms has often been reported. We suggest that conservative therapy with serial angiography is the treatment of choice especially for ischemic-type dissecting aneurysms. We review 17 cases of dissecting aneurysm of the distal PICA in this study.     

Treatment of unruptured saccular vertebral artery aneurysm for preservation of the parent artery for advanced age people: a case report

A 79-year-old female was referred to our hospital presenting with occipital headache. Her unruptured aneurysm was incidentally found by magnetic resonance angiography. Three dimensional computed tomographic angiography showed a saccular aneurysm located at the junction of the left vertebral artery (VA) and posterior inferior cerebellar artery (PICA) that originated from the aneurysm itself. Firstly, surgical clipping of the left PICA just distal to the aneurysm and occipital artery (OA)-PICA bypass was carried out and, secondly, endovascular treatment was performed for preservation of the parent artery.     

A case of cerebellar arteriovenous malformation with hemifacial spasm at onset

A case of cerebellar AVM onset with hemifacial spasm was reported. The patient, a 47 year old woman, had been suffering from lt. hemifacial spasm for 10 years, and she visited our hospital for operation. Preoperative angiography revealed that there was an AVM in the lt. cerebellar hemisphere fed by the lt. SCA and the lt. PICA. In addition, a non-ruptured saccular aneurysm was observed on the feeding SCA. The microvascular decompression was performed and the AVM was removed, since the lt. facial nerve had been compressed by this elongated and redundant PICA. After the operation, lt. hemifacial spasm disappeared. Two months after the operation, the aneurysm disappeared angiographically. These findings indicated that the hemodynamic stress due to the presence of AVM seemed to have resulted in ectasia or redundancy of the PICA and in the development of the aneurysm. Such a case was quite rare and it may be the first time to be reported in literatures.