Posterior inferior cerebellar artery aneurysm associated with persistent primitive hypoglossal artery

A 49-year-old woman presented with subarachnoid hemorrhage (SAH) from an aneurysm associated with a persistent primitive hypoglossal artery (PPHA) manifesting as sudden onset of headache, but without neurological deficits. Conventional computed tomography (CT) of her head showed no abnormality but lumbar tap indicated SAH. Three-dimensional (3D)-CT angiography showed a PPHA originating from the internal carotid artery and an aneurysm of the posterior inferior cerebellar artery at the junction with the remnant hypoplastic vertebral artery. 3D-CT angiography was essentially useful for presurgical planning to determine the extent of craniotomy and the space for possible temporary clipping, and confirmed the diagnosis of aneurysmal SAH. The aneurysm was clipped and she returned to her job 4 weeks later. Cerebral angiography is the golden standard technique to diagnose PPHA, but 3D-CT angiography can be recommended for presurgical evaluation, especially in patients with complex and anomalous anatomical structures.     

Intracerebral hemorrhage from a ruptured aneurysm at the site of anastomosis 27 years after superficial temporal artery-middle cerebral artery bypass

A 77-year-old female presented with a very rare case of intracerebral hemorrhage (ICH) from a ruptured aneurysm at the site of the anastomosis 27 years after superficial temporal artery-middle cerebral artery (STA-MCA) bypass manifesting as sudden onset of unconsciousness and right hemiparesis. Computed tomography (CT) on admission demonstrated massive ICH in the left frontoparietal region. Magnetic resonance angiography showed good patency of the anastomosis and no obvious aneurysm, but three-dimensional CT (3D-CT) angiography revealed a small aneurysm at the site of the left STA-MCA anastomosis. Emergency evacuation of the hematoma was performed, and the aneurysm was trapped and resected after ligation. After the operation, she continued to exhibit deep consciousness disturbance. Unfortunately, her general condition grew steadily worse and she died 3 months later. Patients who undergo STA-MCA anastomosis should be carefully followed up by periodical imaging examinations. 3D-CT angiography is very useful to detect aneurysm formation at the anastomosis site.     

Subarachnoid Hemorrhage after an Ischemic Attack Due to a Bacterial Middle Cerebral Artery Dissecting Aneurysm: Case Report and Literature Review

A 78-year-old woman suffered sudden-onset left hemiparesis. There were no remarkable infectious findings. Computed tomography (CT) demonstrated a low-intensity area supplied by the right middle cerebral artery (MCA). The diagnosis was cerebral ischemia and she was conservatively treated with hyperosmotic fluids. Two days after the ischemic stroke she suddenly became comatose. CT showed diffuse subarachnoid hemorrhage (SAH) in the basal cistern associated with a right intra-Sylvian and a right frontal subcortical hematoma. Three-dimensional (3D)-CT angiography demonstrated occlusion of the M2 portion of the right MCA. Four days after the ischemic onset she died of brain herniation. Autopsy revealed arterial dissection in the intermediate membrane of the right MCA bifurcation and occlusion of the M2 portion of the thrombosed right MCA. Gram staining showed remarkable bacterial infection in the thrombus. SAH after an ischemic attack due to MCA dissection is extremely rare. We suspect that bacterial infection was involved in the formation of her fragile dissecting aneurysm.     

Three-dimensional computerized tomography angiography-guided surgery of acutely ruptured cerebral aneurysms

OBJECT: The aim of this study was to assess whether aneurysm surgery can be performed in patients with ruptured cerebral aneurysms by using three-dimensional computerized tomography (3D-CT) angiography alone, without conventional catheter angiography. METHODS: In a previous study, 60 patients with subarachnoid hemorrhage (SAH) from ruptured aneurysms were prospectively evaluated using both 3D-CT and conventional angiography, which resulted in a 100% accuracy for 3D-CT angiography in the diagnosis of ruptured aneurysms, and a 96% accuracy in the identification of associated unruptured aneurysms. The results led the authors to consider replacing conventional angiography with 3D-CT angiography for use in diagnosing ruptured aneurysms, and to perform surgery aided by 3D-CT angiography alone without conventional angiography. Based on the results, 100 consecutive patients with SAH who had undergone surgery in the acute stage based on 3D-CT angiography findings have been studied since December 1996. One hundred ruptured aneurysms, including 41 associated unruptured lesions, were detected using 3D-CT angiography. In seven of 100 ruptured aneurysms, which included four dissecting vertebral artery aneurysms, two basilar artery (BA) tip aneurysms, and one BA-superior cerebellar artery aneurysm, 3D-CT angiography was followed by conventional angiography to acquire diagnostic confirmation or information about the vein of Labbé, which was needed to guide the surgical approach for BA tip aneurysms. All of the ruptured aneurysms were confirmed at surgery and treated successfully. Ninety-three patients who underwent operation with the aid of 3D-CT angiography only had no complications related to the lack of information gathered by conventional angiography. The 3D-CT angiography studies provided the authors with the aneurysm location as well as surgically important information on the configuration of its sac and neck, the presence of calcification in the aneurysm wall, and its relationship to the adjacent vessels and bone structures. CONCLUSIONS: The authors believe that 3D-CT angiography can replace conventional angiography in the diagnosis of ruptured aneurysms and that surgery can be performed in almost all acutely ruptured aneurysms by using only 3D-CT angiography without conventional angiography.     

Dissection aneurysm of the radiculomedullary branch of the artery of Adamkiewicz with subarachnoid hemorrhage

A 60-year-old female presented with sudden onset of severe headache and back pain, followed by nausea. The initial head computed tomography (CT) scan revealed posterior fossa subarachnoid hemorrhage (SAH). Spinal T(2)-weighted magnetic resonance imaging demonstrated SAH, and a homogeneous and slightly low signal intensity mass at T11. Spinal angiography in the early arterial phase revealed a small pearl and string-like aneurysm of the proximal radiculomedullary artery on the left side at the T12 level. Forty days after the onset of SAH, CT angiography demonstrated complete occlusion of the dissecting aneurysm and the preserved anterior spinal artery. The present case of ruptured dissecting aneurysm of the radiculomedullary branch of the artery of Adamkiewicz with SAH underwent subsequent spontaneous occlusion, indicating that the wait-and-see strategy may be justified and will provide adequate treatment.     

Surgical treatment for subarachnoid hemorrhage of unknown etiology: consideration of radiological findings of digital subtraction angiography

At present, conventional intra-arterial angiography remains the gold-standard for the diagnosis of etiology of subarachnoid hemorrhage (SAH), but this may change as intra-arterial digital subtraction angiography (IA-DSA) or three-dimensional computerized tomography (CT) angiography improve. The purpose of this study is to investigate the reliability of IA-DSA for the diagnosis of SAH of unknown etiology. Of 184 patients admitted to our unit with proven spontaneous SAH between January, 1994, and March, 1997, 124 underwent IA-DSA. Ten were diagnosed as having SAH of unknown etiology by initial angiography; therefore, the incidence of SAH of unknown etiology based on the diagnosis of initial IA-DSA was 8.1%. Of these 10 patients, six patients were treated conservatively in the acute period. Other four patients underwent exploratory surgeries in the acute period due to a great suspicion of the presence of aneurysms. In one patient, no aneurysm was detected; in three patients aneurysms were discovered at surgery and successfully clipped. In two of three patients, aneurysms were not discovered at the suspected site, because radiological findings of a thrombosed aneurysm and infundibular dilatation of a perforator caused incorrect diagnosis of the aneurysm sites. Although the site of aneurysm diagnosed by IA-DSA is not always correct, exploratory aneurysm surgery during the acute period based on the diagnosis by IA-DSA is warranted, and IA-DSA is acceptable for the diagnosis of SAH of unknown etiology.     

Clinico-radiological spectrum of giant intracranial aneurysms

A review of a series of 56 patients with a giant intracranial aneurysm showed that 28 presented with signs related to the mass effect and 19 with subarachnoid hemorrhage (SAH). Additional clinical signs observed were seizures, ischemia, and endocrinological disturbances. Fourty-five aneurysms involved the carotid artery territory and eleven the vertebrobasilar system. On computed tomography (CT) images partially thrombosed aneurysms (23 cases) showed 1) a marginal or central target appearance on contrast enhanced scans corresponding to the non-thrombosed lumen as demonstrated by angiography, 2) capsular enhancement in 16 cases and 3) calcifications in 9. SAH occured in 13 and 6 cases of non-thrombosed and partially thrombosed aneurysms, respectively. Magnetic resonance imaging (MRI) in 6 cases showed several layers of thrombosis in 4 cases and a small signal void close to the parent artery. In one case of a non-thrombosed aneuroysm, thrombosis was mimicked by flow artifacts of MRI.     

Three-dimensional computerized tomography angiography in patients with hyperacute intracerebral hemorrhage.

OBJECT: The authors confirm the usefulness of extravasation detected on three-dimensional computerized tomography (3D-CT) angiography in the diagnosis of continued hemorrhage and establishment of its cause in patients with acute intracerebral hemorrhage (ICH). METHODS: Thirty-one patients with acute ICH in whom noncontrast and 3D-CT angiography had been performed within 12 hours of the onset of hemorrhage and in whom conventional cerebral angiographic studies were obtained during the chronic stage were prospectively studied. Noncontrast CT scanning was repeated within 24 hours of the onset of ICH to evaluate hematoma enlargement. Findings indicating extravasation on 3D-CT angiography, including any abnormal area of high density on helical CT scanning, were observed in five patients; three of these demonstrated hematoma enlargement on follow-up CT studies. Thus, specificity was 60% (three correct predictions among five positives) and sensitivity was 100% (19 correct predictions among 19 negatives). Evidence of extravasation on 3D-CT angiography indicates that there is persistent hemorrhage and correlates with enlargement of the hematoma. Regarding the cause of hemorrhage, five cerebral aneurysms were visualized in four patients, and two diagnoses of moyamoya disease and one of unilateral moyamoya phenomenon were made with the aid of 3D-CT angiography. Emergency surgery was performed without conventional angiography in one patient who had an aneurysm, and it was clipped successfully. CONCLUSIONS: Overall, 3D-CT angiography was found to be valuable in the diagnosis of the cause of hemorrhage and in the detection of persistent hemorrhage in patients with acute ICH.     

Ruptured dissecting aneurysm of the vertebral artery missed by initial angiography; case report]

Dissecting aneurysm of the intracranial arteries is a well known clinical entity, and its angiographic findings are also well recognized. We encountered a case with dissecting aneurysm of the vertebral artery presented with subarachnoid hemorrhage (SAH). The initial angiography was normal but repeated angiography demonstrated a dissecting aneurysm. This case is reported here, and the relevant literature is reviewed. A 46-year-old woman had been well until she complained of headache. She was admitted to a local hospital and found to have SAH. She was transferred to our clinic for further examination. On admission the patient was drowsy but able to be aroused. Her neurological state was normal except for a mildly stiff neck. Computed tomography (CT) demonstrated massive SAH in the basal cistern and intraventricular hemorrhage in all ventricles. CT also demonstrated acute hydrocephalus. Four-vessel cerebral angiography was performed using transfemoral catheterization. No definite abnormalities, except for a small aneurysm in the cavernous portion of the right internal carotid artery, were found. Because aneurysm in the cavernous portion could not cause SAH, we could not define the origin of the SAH. However, retrospectively, a slightly irregular wall of the left intracranial vertebral artery was evident. Repeated angiography performed 28 days later revealed aneurysmal dilatation of this left vertebral artery. Double density of the contrast material was found in the aneurysmal dilatation. Retention of the contrast medium was also seen in the late capillary phase. From these angiographic findings, the aneurysm was diagnosed as being a dissecting aneurysm. Direct surgical attack on the vertebral aneurysm was performed via a left suboccipital craniectomy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Case of specific MRI T2* weighted image associated with bacterial endocarditis

We report a case of multiple signal loss lesions detected by T2* weighted image associated with bacterial endocarditis. A 23 year-old woman, who had undergone surgical closure of ventricular septal defect at age 2, suffered headache and general fatigue after dental treatment. She was admitted to another institution, and examinations revealed bacterial endcarditis. She was transferred to our hospital, and underwent aortic valve replacement. After the valve replacement, CT revealed parenchymal hematoma in the left frontal lobe. CT angiography (CTA) and cerebral angiography (CAG) demonstrated an aneurysm at the distal branch of the left middle cerebral artery. T2* weighted image demonstrated multiple signal loss lesions, which were not revealed by CAG and CTA. We speculated that these signal loss lesions were thrombosed mycotic intracranial aneurysms. She underwent left frontotemporal craniotomy, and the aneurysm was resected. Mycotic aneurysms are rare neurovascular lesions but their mortality and morbidity are high, so careful follow-up examinations are required. T2* weighted image was useful to detect mycotic aneurysms and plan the surgical strategy.     

Subarachnoid hemorrhage of unknown cause

After the institution of computed tomography (CT), 814 cases of spontaneous subarachnoid hemorrhage (SAH) were treated during a period of 6 years and 9 months (April 1978 through December 1984). In 9 (22.0%) of 41 patients whose cause of SAH was not determined by the first four-vessel study (cerebral panangiography), ruptured aneurysms were found by repeated four-vessel study. Thus, of 814 cases, only 32 (3.9%) were diagnosed as cases of unknown etiology at discharge. The 32 cases were monitored by follow-up examination for 5 to 67 months (median, 27.1 months) after onset. No recurrence of SAH was reported, and all patients were rehabilitated except 2 who suffered terminal carcinoma. A third follow-up four-vessel study was performed 8 to 44 months (median, 22.0 months) after the second study in 14 of the 16 patients with SAH initially demonstrated by CT. In 1 of these cases, an aneurysm found 9 months after the initial SAH was treated surgically. Ultimately, 31 cases (3.8%) were diagnosed as cases of SAH of unknown cause. This incidence is low when compared with those in previous reports. Because of the strict examination schedule including repeated angiography, the incidence is lower and the prognosis is relatively favorable.     

Subarachnoid hemorrhage caused by a dissecting aneurysm of the internal carotid artery: case report and review of the literature

A case of subarachnoid hemorrhage (SAH) resulting from a ruptured intracranial dissecting aneurysm of the internal carotid artery (ICA) is reported. A 58-year-old woman presented with headache and vomiting. A CT showed diffuse SAH. A cerebral angiography demonstrated a dissecting aneurysm at the C2 segment of the right ICA. In the present case, trapping with STA-MCA anastomosis was performed and the postoperative course was uneventful. Postoperative follow-up cerebral angiogram detected no aneurysm. SAH caused by the rupture of a dissecting aneurysm of the ICA has been considered rare. To our knowledge, there have been only 29 cases. We discuss the clinical characteristics with a review of the literature.     

Dissecting aneurysm of the posterior communicating artery

Summary. A 36-year-old male presented with an extremely rare dissecting aneurysm of the posterior communicating artery manifesting as severe occipital headache. Magnetic resonance (MR) imaging revealed a partially thrombosed aneurysm of the right posterior communicating artery and angiography showed the pearl and string sign. Three months later, repeat angiography showed that the aneurysm was completely thrombosed and the posterior communicating artery was occluded. Magnetic resonance (MR) imaging showed an intimal flap. These neuroradiological findings demonstrated that the aneurysm was a dissecting aneurysm of the right posterior communicating artery. He was discharged with no neurological deficit.     

Use of spiral computerized tomography angiography in patients with subarachnoid hemorrhage in whom subtraction angiography did not reveal cerebral aneurysms

OBJECT: Patients with subarachnoid hemorrhage (SAH) in whom angiography does not demonstrate diagnostic findings sometimes suffer recurrent disease and actually harbor undetected cerebral aneurysms. The management strategy for such cases remains controversial, but technological advances in spiral computerized tomography (CT) angiography are changing the picture. The purpose of this prospective study was to examine how spiral CT angiography can contribute to the detection of cerebral aneurysms that cannot be visualized on angiography. METHODS: In 134 consecutive patients with SAH, a prospective search for the source of bleeding was performed using digital subtraction (DS) and spiral CT angiography. In 21 patients in whom initial DS angiography yielded no diagnostic findings, spiral CT angiography was performed within 3 days. Patients in whom CT angiography provided no diagnostic results underwent second and third DS angiography sessions after approximately 2 weeks and 6 months, respectively. Six patients with perimesencephalic SAH were included in the 21 cases. Six of the other 15 patients had small cerebral aneurysms detectable by spiral CT angiography, five involving the anterior communicating artery and one the middle cerebral artery. Two patients in whom initial angiograms did not demonstrate diagnostic findings proved to have a ruptured dissecting aneurysm of the vertebral artery; in one case this was revealed at autopsy and in the other during the second DS angiography session. A third DS angiography session revealed no diagnostic results in 13 patients. CONCLUSIONS: Spiral CT angiography was useful in the detection of cerebral aneurysms in patients with SAH in whom angiography revealed no diagnostic findings. Anterior communicating artery aneurysms are generally well hidden in these types of SAH cases. A repeated angiography session was warranted in patients with nonperimesencephalic SAH and in whom initial angiography revealed no diagnostic findings, although a third session was thought to be superfluous.     

An infected partially thrombosed giant aneurysm of the azygos anterior cerebral artery

The authors report a case of partially thrombosed giant aneurysm which was secondarily infected with purulent meningitis. The relationship between the infection of the aneurysm, the rapid growth of the aneurysm and the development of severe cerebral edema was discussed. A 53 year-old man was admitted on September 1, 1986, with a diagnosis of bacterial meningitis. On his admission, his body temperature was 39 degrees C, and he showed mental confusion but no neurological deficits. Laboratory data revealed signs of infection in white blood cell count, CRP, and erythrocyte sedimentation rate. Computerized tomographic (CT) scan and magnetic resonance (MR) imaging showed a massive round mass with perifocal edema measuring 40mm in the maximum diameter in the left paramedian frontal region. T1 weighted MR image also showed the presence of pus accumulation in the left ventricle. Cerebral angiography demonstrated a giant aneurysm at the distal portion of the azygos anterior cerebral artery, and irregular narrowing of both the supraclinoid segment of the carotid artery and its main branches indicating arteritis due to purulent meningitis. The patient was treated with ventricular drainage and administration of antibiotics. Culture of the purulent CSF was negative. The patient's lab data, CSF finding and neurological status improved progressively. However, follow-up CT scan and angiogram a month later showed enlargement of the aneurysm, dilatation of the patent lumen and perifocal edema. On October 8, the patient suddenly became comatose with anisocoria. A CT scan showed massive edema with marked midline shift. Emergency bifrontal craniotomy was carried out, and clipping was completed after removal of the thrombosed portion of the aneurysm, and thromboendarterectomy of the aneurysmal neck.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surgical anatomy of the cerebral arteries in patients with subarachnoid hemorrhage: comparison of computerized tomography angiography and digital subtraction angiography.

OBJECT: The purpose of this study was to compare computerized tomography (CT) angiography and digital subtraction (DS) angiography studies in patients with subarachnoid hemorrhage (SAH) to assess their vascular anatomy relevant to cerebral aneurysm surgery. METHODS: From a prospective series of 100 patients with SAH, the authors selected 73 patients whose CT angiography studies were of adequate quality and in whom DS angiography of both carotid arteries had been performed. Eleven patients with no DS angiographic studies of the vertebrobasilar artery were only evaluated for the anterior half of the circle of Willis. Anterior communicating arteries (ACoAs), both precommunicating anterior cerebral arteries (A1 segments), both posterior communicating arteries (PCoAs), and both precommunicating posterior cerebral arteries (P1 segments) were assessed on CT angiography and DS angiography by two independent observers. CONCLUSIONS: Computerized tomography angiography compares well with DS angiography for visualizing normal-sized arteries, and is superior for visualizing ACoAs and hypoplastic A1 and P, segments. Important preoperative aspects such as dominant A1 segments and PCoAs are equally well seen using either modality. Neither method enabled the authors to visualize more than 50% of PCoAs. Use of CT angiography can provide the required preoperative anatomical information for aneurysm surgery in most patients with SAH.     

Usefulness of CT angiography for demonstrating cerebral aneurysms

We report the usefulness of computed cerebral angiotomography (CT angiography) for demonstrating cerebral aneurysm and the clinical significance of CT angiography for ruptured cerebral aneurysm. Our modified method of CT angiography was easy and less time-consuming. Fifteen seconds after starting a single bolus injection, 1 ml/kg/25 seconds via cubital vein, of contrast medium (60% urograffin), 5 serial 5 mm thick-CT slices were scanned in every 6.5 seconds including 2 seconds of interval, beginning from an axial level 20 mm above the orbitomeatal line and ending at a level 40 mm. A total of 103 patients were examined in this report, consisting of 70 unruptured asymptomatic, 8 unruptured symptomatic (oculomotor nerve palsy) and 25 subarachnoid hemorrhage (SAH). Seven unruptured aneurysms in 4 asymptomatic cases, 2 unruptured aneurysms in 2 symptomatic cases 27 aneurysms in 24 SAH cases were suspected by CT angiography. Of these 36 aneurysms suspected by CT angiography 32 aneurysms were confirmed by cerebral angiography. The detection rate of CT angiography in this report was 89%, higher than those of previous reports. Thirteen aneurysms were located at internal carotid-posterior communicating artery (ICPC) junction. 11 at anterior communicating artery (Acom), 7 at middle cerebral artery (MCA). CT angiography showed a false positive findings in 4 cases, which were all located at Acom. Four aneurysms were not detected in CT angiography, which were all located at MCA and were very small (2-3 mm) in diameter. There were no deteriorated cases during and after CT angiography. We suggest that CT angiography is a useful and safe method for predicting the location of not only unruptured but ruptured aneurysms.     

A case of ex vivo renal artery reconstruction and autotransplantation for renal artery aneurysm

A 74-year male patient was admitted to our department with a left renal artery aneurysm (RAA). It was detected by a computed tomography (CT) scan while performing an examination for hypertension. The diameter of the aneurysm was 25 mm. There was no evidence of calcification. Selective left renal angiography and a 3-dimensional (3D)-CT image revealed a saccular renal aneurysm in the left main renal artery. Because of the risk of rupture, autotransplantation of the left kidney to the left iliac fossa was performed after resecting the aneurysm and reconstructing the left artery under bench surgery. Postoperative 3D-CT revealed no stenosis. This ex-vivo technique and autotransplantation into ipsilateral iliac fossa are both effective and safe for the treatment of RAA.     

Enlargement to a saccular aneurysm and subsequent rupture of infundibular widening of posterior communicating artery

A small dilatation known as infundibular widening (IFw) is frequently seen (7%-25%) on the posterior communicating artery (PComA) at its origin from the internal carotid artery. Development and subsequent rupture of an aneurysm on a previously radiographically demonstrated IFw has rarely been documented. We present two patients who suffered from subarachnoid hemorrhage (SAH). Initial cerebral angiography demonstrated IFw on PComA. They were readmitted to the hospital 9 and 11 years later, after a new SAH. Repeated cerebral angiography revealed an aneurysm arising from the site where the IFw had been seen previously in both cases. The aneurysms were clipped with favorable outcome. This report adds two new cases documenting enlargement of PComAIFw into an aneurysm. Patients with PComAIFw, especially those who have experienced SAH, should be considered for periodic follow-up to rule out the development of an aneurysm over time.     

Spontaneous Total Thrombosis of Distal Superior Cerebellar Artery Aneurysm

Summary. We report the case of an aneurysm of the distal segment of the superior cerebellar artery (SCA) which showed complete spontaneous thrombosis. Initial angiography performed in another institution showed 3 non-ruptured aneurysms located on the right distal SCA, C3 segment of the right internal carotid artery (ICA) and left basilar artery (BA) – SCA bifurcation. The patient had two episodes of transient cerebellar ataxia of the right hand before admission to our hospital, but no neurological signs were noted on admission. Computed tomography (CT) and magnetic resonance image (MRI) showed a thrombosed mass on the right cerebellar peduncle, and angiography showed no filling of the right SCA from its origin. A follow up angiogram 9 month after endovascular surgery for other aneurysms showed no recanalization of SCA or the aneurysms. There are no previous reports of total spontaneously thrombosed non-giant aneurysms of the distal segment of the SCA.