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.     

Aneurysms of the distal posterior inferior cerebellar artery; the report of 10 cases

Non mycotic and non traumatic distal posterior inferior cerebellar artery (PICA) aneurysms are rare, but eleven aneurysms in ten cases were reported. They all originated from subarachnoid hemorrhage due to rupture of these aneurysms. The patients in these cases were all admitted within 5 days after the onset. The neurological state of four cases on admission was grade 4 or 5 in Hunt and Kosnik's grading system. Two patients of grade 5 died within 24 hours after the onset. The CT scan on admission revealed heavy subarachnoid hemorrhage mainly in the posterior fossa. In severe cases, ventricle hematoma, cerebellar hematoma and/or subdural hematoma were evident in the posterior fossa. The locations of these eleven aneurysms were as follows: On the bifurcation of the Telovelotonsillar segment in six cases. In the cortical segment in three cases. In the anterior medullary and tonsillomedullary segment in one case. Six saccular aneurysms were situated on bifurcations of parent arteries but three saccular aneurysms did not arise from bifurcations. Two of them were not from turning points of the arteries. One fusiform aneurysm situated on the bifurcation of telovelotonsillar segment was excised, and histologically shown to be a dissecting aneurysm with hypoplasia of elastic lamina and tunica media in the parent artery. Three cases were associated with small AVM located on the superior surface of the cerebellar vermis and fed mainly by the superior cerebellar artery (SCA) in two cases, and by SCA and PICA in one case. In these cases the hemodynamic stress on PICA did not seem to increase so remarkably.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

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.     

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

Aneurysms rarely occur at the choroidal branch of the posterior inferior cerebellar artery (PICA) and their pathogenesis is not well understood. We report such a case and review the literature. A 69-year-old female was admitted for a sudden onset of severe headache with nausea and vomiting. Soon after arrival, she became less responsive. CT of the head revealed an intraventricular haemorrhage (IVH) predominantly in the fourth and third ventricles without subarachnoid hemorrhage and associated with hydrocephalus. Cerebral angiography demonstrated an aneurysm at the choroidal branch of the PICA. The aneurysm was resected through a bilateral suboccipital craniotomy. The patient made a remarkable recovery. The literature describes five other cases of aneurysms arising from a choroidal branch of the PICA. Hypertension was a common finding in this population. In summary, aneurysms arising from a choroidal branch of the PICA are rare. Hypertensive vessel damage might be a major factor in their pathogenesis. We propose that the rupture of a hypertensive aneurysm might account for some isolated spontaneous IVH.     

Aneurysms of the distal posterior inferior cerebellar artery--analysis of 14 aneurysms in 13 cases

Thirteen cases of distal posterior inferior cerebellar artery (PICA) aneurysms are reported here. All the aneurysms were found after a subarachnoid hemorrhage. Dissecting aneurysm, incidentally found unruptured aneurysms, and aneurysms associated with arteriovenous malformation have been eliminated from this study. Characteristics for this type of lesion are a high rate of recurrent hemorrhage and rapid death due to direct compression of the brain stem, which clearly indicates the necessity of early surgery. Attention should be paid to the fact that angiography cannot always reveal aneurysms, especially when they are located in the peripheral PICA. One should also pay attention to multiple lesions and rapid growing acute subdural hematoma as initial findings for ruptured distal PICA aneurysm. Prognostic factors for these lesions are, vasospasm, especially when the aneurysm is located proximally in the PICA, and direct compression of the brain stem due to intraventricular hemorrhage when the aneurysm is located distally. It has been suggested that the pathogenesis of this lesion could be hemodynamic stress or embryogenesis. The shape and anomalous arterial structures of the 14 aneurysms presented here tend to agree with this suggestion. Our results suggest that the pathogenesis is hemodynamic stress that had developed due to embryological and/or arteriosclerotic factors.     

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.     

Multiple aneurysms of the distal posterior inferior cerebellar artery with recurrent hemorrhage undetectable on preoperative neuroradiological findings: case report

We report a rare case of multiple aneurysms of the distal posterior inferior cerebellar artery (PICA) associated with recurrent hemorrhage undetectable on preoperative neuroradiological findings. A 68-year-old woman was admitted to our hospital in April, 2003 because of a sudden onset of headache, back neck pain and nausea. CT scan at the time of admission showed a hematoma in the 4th & 3rd ventricles, and a mild subarachnoid hemorrhage (SAH) in the basal, right ambient & quadrigeminal cisterns. She had had a similar history of previous intraventricular hemorrhage and SAH in October, 2001. Three-dimensional CT angiograms and left vertebral angiograms performed at that time revealed an irregular vascular lesion at the tonsillomedullary segment (TMS) of the left PICA. However, the final diagnosis was unclear. Left vertebral angiograms at the time of the 2003 admission revealed an irregular vascular lesion in the same region more clearly and the size of aneurysmal dilatations had increased considerably. So, preoperative diagnosis of an irregular vascular lesion at the TMS of the left PICA (distal PICA aneurysm was not ruled out) was based on the above neuroradiological findings. The patient was surgically treated through the suboccipital approach. The TMS of the left PICA had made a difficulty loop formation was observed. Five distinct aneurysma were found on the TMS of the left PICA. To prevent bleeding, the ruptured aneurysm & three unruptured aneurysms were clipped and the residual unruptured one was wrapped with Bemsheets. Postoperative left vertebral angiograms demonstrated neither clipped aneurysms nor occlusive findings at the TMS of the PICA. The patency of the PICA was preserved. The postoperative course was uneventful and the patient was discharged without new neurological deficits. There has been no rebleeding during the one year since surgery. The 23 reported cases of multiple aneurysms of the distal PICA including our case were reviewed and their neuroradiological and clinical features are discussed.     

Distal aneurysm of posterior inferior cerebellar artery: report of two cases--pitfall in diagnosis

Two cases treating aneurysms of the distal PICA were reported, and 36 cases with 39 aneurysms in the literatures in Japan were reviewed concerning the distribution of aneurysms and their findings on CT. Case 1; a 68-year-old female suffered from sudden onset of severe headache and nausea. On admission, it was found she was lethargic. However, her consciousness deteriorated down to semicoma with tetraparetic condition soon after. CT revealed subarachnoid hemorrhage in the basal, quadrigeminal and supravermian cisterns and blood clots in the entire ventricle. Cerebral angiography demonstrated an aneurysm located at the distal segment of the left PICA. She was initially treated conservatively because of being in Hunt and Kosnik Grade 5, and then, 3 weeks after onset, suboccipital craniectomy was performed and the aneurysm was clipped successfully. Case 2; a 60-year-old, female, suddenly experienced severe suboccipitalgia and vomiting. CT revealed subarachnoid hemorrhage in the entire subarachnoid space and intraventricular hemorrhages in the 4th, 3rd and lateral ventricles. Subsequently cerebral angiography was performed and left VAG demonstrated an aneurysm at the left A2-A3 junction. She underwent bifrontal craniotomy and the aneurysm was clipped via the interhemispheric approach. Her postoperative course was uneventful. Postoperative left CAG showed successful clipping of the aneurysm. However, left VAG suggested an aneurysm-like shadow in the right PICA. Right BAG carried out one week later demonstrated an aneurysm at the distal segment of the right PICA. This aneurysm was then clipped successfully under suboccipital craniectomy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Distal posterior cerebellar artery aneurysm: case report

Vertebrobazilar aneurysms make about 15% of all intracranial aneurysms, from which one fifth belongs to aneurysms a posterior inferior cerebelli (PICA). Majority of PICA aneurysms is located in the place of separation from a.vertebralis. Aneurysms of distal part of PICA are very rare, according to literature they make 0.5 to 3% of all aneurysms. 70 years old man came to neurologist because sudden headache, pain in the neck and a feeling of stiffness followed by throwing up in stream. On the occasion of medical check up attack of spontaneous subarachnoid hemorhage was suspected. Clinical gradus according to H&H III, initial CT of endocranium showed existence of smaller intracerebellar hematoma next to lateral wall of IV ventricle and trace of blood in the very ventricle without signs of acute hydrocephalus. The seventh day after the hemorrhage angio CT was done and it showed existence of aneurysm on distal part of PICA, more specially in the televelotonzilar segment on the right. After the diagnostics supplemented with standard digital substractional angiography which confirmed nature and localization of the lesion. In the postponed procedure, and in conformity with strategy of surgical timing of aneurysms in the back circulation, patient was operated three weeks after the attack of hemorrhage. Disregarding low incidence of existence of aneurysms of distal circulation (under 1% of all in the back circulation) high level of suspicion should be present and angio CT should be done as screening method, if CT shows hemorrhage which according to localization responses to possible aneurysm.     

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.     

Familial cerebral aneurysms in three families, with two sibling pairs

The authors describe two pairs of siblings and a mother-son with cerebral aneurysms and the characteristics of familial intracranial aneurysms are briefly discussed. Family 1: A 54-year-old hypertensive woman (case 1) developed subarachnoid hemorrhage and a saccular aneurysm at the proximal portion of the left anterior cerebral artery was demonstrated on the angiogram. An azygos anterior cerebral artery was found as an associated anomaly. A 53-year-old hypertensive woman (case 2), a younger sister of case 1, suffered from subarachnoid hemorrhage and a saccular aneurysm at the distal portion of the right anterior cerebral artery was found on the angiogram. Vertebral angiogram showed bilateral fenestration of the extracranial vertebral arteries as a coincidental anomalies. Neck clipping for the aneurysms were successfully done in these two cases. Family 2: A 52-year-old hypertensive woman (case 3) suffered from subarachnoid hemorrhage and vertebral angiogram demonstrated a saccular aneurysm at the distal portion of the right posterior inferior cerebellar artery. The aneurysm was re-bled before surgical intervention and she died five days after admission. A 65-year-old hypertensive woman (case 4), an elder sister of case 3, was admitted with subarachnoid hemorrhage. Vertebral angiogram showed a saccular aneurysm on the proximal portion of the left posterior inferior cerebellar artery at the junction of the vertebral artery and a massive extravasation of the contrast medium from the aneurysm. The patient died three days after the onset before surgical intervention.(ABSTRACT TRUNCATED AT 250 WORDS)     

Peripheral aneurysms of the posterior inferior cerebellar artery; analysis of 15 cases]

Peripheral aneurysms of the posterior inferior cerebellar artery (PICA) are rare. The authors report 15 cases of peripheral PICA aneurysms. Twelve of the aneurysms were discovered after their rupture and two were discovered after rupture of concomitant AVM, and one was detected incidentally. As to the location of aneurysms, more than half of the aneurysms arose at the telovelotonsillar segment. One patient had 2 aneurysms on the same peripheral PICA, which were not obvious on preoperative angiography because the ruptured one was partially thrombosed. Another rare case with aneurysm located at the internal auditory meatus is also reported. The findings of CT were characteristic, namely hemorrhage in the fourth ventricle without obvious hemorrhage in the basal cisterns, or only within the cerebellar vermian cistern. This phenomenon strongly suggested the possibility of rupture of peripheral PICA aneurysms. As to the surgical results, 10 patients (71%) of the 14 patients had a good recovery, and 1 patient (7%) with nonrupture aneurysm had a fair result due to pre-existing pontine hemorrhage. Three patients (21%) died. Rebleeding occurred in 3 patients, but cerebral vasospasm occurred in only 1 patient. Consequently, as peripheral PICA aneurysms are likely to be missed, and rebleeding is an unfavorable factor, one should try to demonstrate aneurysms with angiography, by using various methods such as subtraction or magnification.     

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.     

An arterial dissection of the distal anterior inferior cerebellar artery treated by endovascular therapy

A rare case of a dissection of the distal anterior inferior cerebellar artery (AICA) is presented. A 68-year-old woman with sudden onset of headache was admitted. Computed tomographic (CT) scan demonstrated no subarachnoid hemorrhage. Seven days later, CT scan revealed subarachnoid and intraventricular hemorrhage. Left vertebral angiogram showed an aneurysmal dilatation on the distal AICA with a diagnosis of suspected arterial dissection. At that time, we chose delayed craniotomy to observe the lesion directly. However, rebleeding causing aggravation of the patient's systemic condition delayed radical treatment. 19 days after rebleeding, by a superselective angiogram, endovascular treatment was selected to prevent further bleeding. The lesion was diagnosed as dissection of the AICA. The parent AICA was occluded with a Guglielmi detachable coil and fibered platinum coils. Dissection of the distal portion of the cerebellar artery is rare. Only six cases have been reported in the posterior inferior cerebellar artery (PICA) and two cases in the superior cerebellar artery (SCA). However, to our knowledge, no such case has been reported in the AICA. Ruptured dissection of distal PICA or SCA is reported to require early treatment to prevent further bleeding. Ruptured dissection of the distal AICA also requires early treatment. Two cases of distal dissection of PICA and SCA successfully treated by endovascular treatment are reported. Endovascular treatment has some benefits in that it does not always require general anesthesia and in that it can follow diagnostic angiography. On the other hand, saccular aneurysms of the distal AICA do not always require early treatment, such as removal of hematoma because of low incidence of vasospasm. So, to decide the treatment, precise diagnosis of the dissection is very important.     

Fenestration of the posteroinferior cerebellar artery: case report

OBJECTIVE AND IMPORTANCE: Fenestrations of cerebral arteries are rare, but very important to diagnose given their high association with saccular aneurysms. We present the first reported case of a fenestration of the posteroinferior cerebellar artery (PICA). CLINICAL PRESENTATION: A 62-year-old man who presented with a subarachnoid hemorrhage underwent repeated four-vessel cerebral angiography. An isolated right PICA abnormality consistent with a dissection or fenestration was revealed. INTERVENTION: The patient underwent surgical exploration of his PICA, which confirmed a PICA fenestration without an associated saccular aneurysm. The fenestration was wrapped with cotton. CONCLUSION: Our case report illustrates the novel anatomic finding of a fenestration of the PICA. Knowledge of this entity would be helpful in the differential diagnosis of a posterior fossa subarachnoid hemorrhage.     

Unexpected delayed rupture of the vertebral-posterior inferior cerebellar artery aneurysms following closed head injury

Subarachnoid haemorrhage secondary to closed head injury is rarely associated with traumatic aneurysms of the posterior circulation. We report two cases of ruptured vertebral-posterior inferior cerebellar artery (VA-PICA) pseudoaneurysms following closed head injuries. In each case, there was no associated penetrating injury or skull fracture. The first patient was kicked followed by disturbed consciousness. The computerized tomography (CT) scan on admission and cerebral angiography on the 11th day after the trauma revealed a massive subarachnoid haemorrhage (SAH) with pan-ventricular haemorrhage and an aneurysm of the right PICA near its origin. Further ruptures occurred on the 12th, 15th, and 66th day, and he died on the 69th day. The second patient complained of persistent headache and nausea following a fight on the previous day. A CT scan and angiography on the 1st day after the trauma showed posterior fossa SAH with fourth ventricular blood and a tiny protrusion of the left VA-PICA. On the 14th day, repeated angiography revealed a remarkable growth of the aneurysm, followed by the second rupture. The repair of the VA-PICA junction was urgently performed with successful exclusion of the aneurysm. To our knowledge, only eight cases of traumatic aneurysms located at the VA or the PICA near its origin have been reported. When intraventricular blood is found with massive subarachnoid blood or with posterior fossa SAH, this ominous complication should be considered. Traumatic VA-PICA pseudoaneurysms are curable by refined microsurgical techniques, if diagnosed in time.     

Delayed post-traumatic saccular aneurysm of PICA in an adolescent

Delayed traumatic intracranial aneurysms of the posterior circulation caused by nonpenetrating head injury are rare, especially in pediatric patients. The true incidence and natural history of these aneurysms are poorly understood. We report a case of a 15-year-old boy who initially presented with subarachnoid hemorrhage of the posterior fossa without any evidence of associated aneurysm. On a routine computed tomography of the head, however, he was found to have a saccular aneurysm of the proximal posterior inferior cerebellar artery. The patient was treated successfully by microsurgical clipping and PICA/PICA bypass.     

Ruptured aneurysms of the choroidal branches of the posterior inferior cerebellar artery: a review of the literature and a case report

Aneurysms of the choroidal branches of the posterior inferior cerebellar artery (PICA) are quite rare; only seven such cases have been reported thus far. In this study, we present a very rare case of a ruptured aneurysm of a choroidal branch of the PICA; the aneurysm was exposed by splitting the vermis and resected after proximal arterial ligation. We have also undertaken a thorough review of the literature on aneurysms in choroidal branches of the PICA, focusing on the clinical presentation, etiology, radiological findings, and surgical strategies. We found that the aneurysms in our patient and the aneurysms in seven published case reports were small, and frequently associated with vascular anomalies. Intraventricular hemorrhage (IVH) in the fourth ventricle was detected in all eight cases. The outcomes of surgical treatment were generally favorable, notwithstanding the high incidence of rebleeding after rupture of distal PICA aneurysms. The recognition of predominant fourth ventricular hemorrhage should raise the suspicion of the presence of an underlying aneurysm, and digital subtraction angiograms (DSAs) should be immediately obtained in order to detect small aneurysms of the choroidal branches of the PICA.