Single-stage extracranial carotid artery stenting and intracranial aneurysm coiling: technical feasibility and clinical outcome

The coexistence of carotid artery stenosis and cerebral aneurysm in a patient presents challenges for treatment decision-making. The purpose of this study was to evaluate the technical feasibility and clinical outcome after single-stage extracranial carotid artery stenting (CAS) and ipsilateral intracranial aneurysm coiling in a single institution. From March 2005 to February 2011, 17 patients with 21 aneurysms underwent single-stage CAS and coiling for ipsilateral aneurysms. There were symptomatic atherosclerotic carotid stenoses with unruptured aneurysms in eight, ruptured or symptomatic aneurysms with simultaneous asymptomatic carotid stenoses in two and asymptomatic lesions in seven. CAS was followed by aneurysm coiling in all 17 patients. Clinical and radiological data were reviewed. There were two procedure-related complications: acute in-stent thrombosis in one and premature aneurysmal rupture in the other. After aneurysm coiling, complete occlusion was demonstrated in 17 aneurysms and near-total occlusion in four. No neurological deficit was found at discharge and follow-up outcomes were excellent in all the patients (mean, 32.9 months). Follow-up imaging studies were performed in all the patients, including neck CT angiography in 14 (mean, 26.1 months), brain MR angiography in 14 (mean, 31.2 months), and conventional angiography in three (mean, 14.7 months). They revealed two asymptomatic, mild carotid re-stenoses and one major aneurysmal recanalization requiring re-coiling. A single-stage CAS and coiling procedure appears to be feasible and the complication rate seems to be reasonable. We suggest that there is no need for separate therapeutic procedures when a patient has carotid artery stenosis and accompanying ipsilateral intracranial aneurysm.

Feasibility of intravenous flat panel detector CT angiography for intracranial arterial stenosis

BACKGROUND AND PURPOSE

I.v. FDCT angiography is an emerging technology for the detection of intracranial vascular disease. This study was conducted to determine the feasibility of i.v. FDCT in estimating major atherosclerotic intracranial arterial stenosis with DSA as the reference.

MATERIALS AND METHODS

DSA and i.v. FDCT were performed simultaneously in patients with transient ischemic attack or acute cerebral infarction. The degree and length of stenosis were measured. The stenotic vessels were categorized into 4 groups by the grade of stenosis: normal (<30%), mild (30%-49%), moderate (50%-69%), or severe (>70%). The vessels of the normal group were excluded from analysis to reduce spectrum bias. Measurement of vessels was recorded by using an electric ruler by a qualified endovascular neurosurgeon and a neuroradiologist.

RESULTS

Eight hundred forty-two vessel segments in 69 patients were calculated. Mild (n = 56), moderate (n = 47) and severe stenosis (n = 46) groups were analyzed. I.v. FDCT had a sensitivity of 97.6%, specificity of 96.9%, and negative predictive value of 96.9% for detecting ≥50% stenosis and respective values of 91.9%, 98.2%, and 97.4% for depicting ≥70% stenosis. The difference of stenotic length between the 2 tests was not significant as an increase in the severity of stenosis (Spearman rank correlation test; r = -0.12, P = .13).

CONCLUSIONS

I.v. FDCT can be a feasible alternative as a noninvasive method for evaluating stenosis of the major intracranial arteries.

Stenting from the vertebral artery to the posterior inferior cerebellar artery

BACKGROUND AND PURPOSE

There are only a few reports on the feasibility and safety of stents used in the PICA, and clinical and angiographic follow-up results have not been fully addressed. We report our experiences of treating PICA origin or vertebral artery-PICA lesions by using self-expanding stents as adjuvant or rescue therapy with angiographic and clinical follow-up results.

MATERIALS AND METHODS

Six patients were treated with self-expanding stent placements from the vertebral artery to the PICA. Two patients had a vertebral artery dissecting aneurysm involving the PICA origin, 3 had vertebral artery-PICA aneurysms, and 1 had segmental stenosis of the vertebral artery harboring the origin of the PICA. The safety, feasibility, and follow-up angiographic results were retrospectively evaluated.

RESULTS

All procedures were successfully performed without any procedure-related complications. None of the patients showed PICA territorial infarction on DWI posttreatment. All patients were neurologically intact during the clinical follow-up of 3-24 months following the procedure. Follow-up angiography was performed at between 6 and 12 months in 5 of the 6 patients and was scheduled for the sixth patient but was not performed. The PICA showed good patency without in-stent stenosis in all 5 patients.

CONCLUSIONS

In patients with lesions of the PICA origin or vertebral artery-PICA lesions, vertebral artery-to-PICA stent placement may be an option for preserving PICA patency in selected cases.

Preinterventional clopidogrel response variability for coil embolization of intracranial aneurysms: clinical implications

BACKGROUND AND PURPOSE

Thromboembolism is one of the most serious complications in coil embolization for intracranial aneurysms, and antiplatelet premedication may reduce this complication. However, interindividual variation exists in the efficacy of CPG. This study sought to elucidate the clinical implications of preinterventional CPG response variability in patients who undergo coil embolization for intracranial aneurysms.

MATERIALS AND METHODS

CPG premedication was given to 186 consecutive patients with 209 aneurysms who underwent elective coil embolization, and the response to the premedication was measured by a point-of-care antiplatelet function test (VerifyNow assay). Patients were stratified into 4 quartiles according the test results, and their correlation with the occurrence of periprocedural complications was analyzed. The contribution of a variety of variables to the high PRU was also tested.

RESULTS

In this cohort, rates of thromboembolic events and all adverse events were 7.5% and 9.1%, respectively. The quartiles of the P2Y12 reaction unit of the ADP channel (PRU) showed a significant tendency toward thromboembolic events (P = .013) and all procedure-related adverse events (P = .009), while those of the BASE and percentage inhibition did not. Thromboembolic events occurred in 17.0% and procedure-related adverse events, in 21.3% of the patients in the fourth quartile. Female sex was the only significant factor related to the fourth quartile of PRU in the multiple logistic regression analysis (P = .014).

CONCLUSIONS

Procedure-related thromboembolic events occurred more frequently in patients in the upper quartile with higher PRU, especially in the fourth quartile. Further study including a large number of patients is expected to confirm this finding.

Muslinoma and muslin-induced foreign body inflammatory reactions after surgical clipping and wrapping for intracranial aneurysms: imaging findings and clinical features

Object

Reinforcement of aneurysms with additional wrapping is an alternative procedure if the aneurysm cannot be completely clipped. Wrapping with muslin (cotton gauze) rarely incites foreign body inflammatory reactions. In this study, the authors describe the clinical and radiological features of muslinomas or muslin-induced foreign body reactions that can develop after treatment of intracranial aneurysms.

Methods

Over a 3-year period, 5 patients with muslinomas underwent treatment at the authors' institution. All patients underwent aneursym clipping and wrapping, and were subsequently readmitted with acute or subacute neurological symptoms. Clinical and imaging features on diffusion weighted MR images and cerebral angiography images were retrospectively reviewed. The patients' clinical course and follow-up imaging studies were also evaluated.

Results

In all 5 cases, muslinomas were seen as rim-enhancing inflammatory masses around the clipped aneurysms with perilesional edema visible on MR images at the time of clinical deterioration. The MR images also demonstrated adhesive arachnoiditis with a sterile intracranial abscess in 3 patients, optic neuropathy in 2, parent artery narrowing in 2, and a resultant acute ischemic infarction in 1 patient. Follow-up imaging revealed resolution of both the perilesional edema and adhesive arachnoiditis but no significant changes in the muslinomas. All patients underwent conservative management and fully recovered, but during the follow-up period, 2 patients experienced clinical and radiological relapses.

Conclusions

When a patient with a history of wrapping of an aneurysm presents with acute neurological symptoms and an enhancing intracranial mass in the region of the surgical site on MR imaging, a muslin-induced foreign body inflammatory reaction should be considered in the differential diagnosis, and careful clinical and radiological follow-up is advised.

Intraosseous cranial dural arteriovenous fistula treated with transvenous embolization

BACKGROUND AND PURPOSE

We analyzed the angiographic architecture of intraosseous dural arteriovenous fistulas (DAVFs) and evaluated the use of transvenous embolization for curative treatment.

MATERIALS AND METHODS

The study population consisted of 6 patients with intraosseous DAVFs from 3 hospitals. In all of these patients, we retrospectively reviewed the medical records and images, and we were able to confirm the lesions in all patients from CT, MR imaging, and angiographic images. 3D rotational angiographic coronal source images clearly demonstrated the presence of an intraosseous DAVF in 2 patients.

RESULTS

An intraosseous DAVF was located at the upper clivus in 1, the petrous apex in 1, and the lower clivus adjacent to the hypoglossal canal in 4 cases. All of the cases showed the presence of a dilated venous pouch, manifest as an osteolytic lesion on CT and as an intraosseous signal-intensity void on MR images. All patients were treated with transvenous embolization by targeting the dilated venous pouch and its connecting tributaries. Four intraosseous DAVFs were immediately completely embolized. One patient had a residual shunt, but the shunt disappeared 1 month later. One patient presented with a simultaneous DAVF in the ipsilateral cavernous sinus without a significant amount of shunt. None of the patients had procedural complications, and 5 patients recovered from the presenting symptoms.

CONCLUSIONS

An intraosseous DAVF could be completely cured with transvenous embolization. For curative treatment, the intraosseous dilated venous pouch can be the target lesion for endovascular treatment.

Endovascular coil embolization of 435 small asymptomatic unruptured intracranial aneurysms: procedural morbidity and patient outcome

BACKGROUND AND PURPOSE

Whether treatment of small asymptomatic aneurysms is appropriate or not remains controversial. We performed a retrospective study on the procedural morbidity and mortality of coil embolization of small asymptomatic unruptured intracranial aneurysms (UIAs) to obtain a more generalized estimate of procedural risk.

MATERIALS AND METHODS

A total of 435 small (maximum diameter < or = 7 mm) asymptomatic UIAs in 370 patients were treated by coil embolization. Aneurysm sizes were determined by using 3D angiograms. We assessed procedure-related morbidity and mortality, immediate postprocedural angiographic results, short-term imaging follow-up results, and clinical outcomes.

RESULTS

Initial aneurysm occlusion was complete in 334 aneurysms, near complete in 78, and incomplete in 22. One internal carotid artery (ICA) aneurysm that ruptured during the procedure was treated with parent artery occlusion. Two hundred wide-neck aneurysms were coiled with the aid of various neck-remodeling techniques. The 44 procedure-related complications were the following: 24 thromboembolisms, 11 coil protrusions or prolapses into the parent vessel, 4 intraprocedural ruptures, 3 device-related complications, and 2 femoral-access complications. We had a total of 44 (10.1%) procedure-related complications with only 1 leading to persistent neurologic deficit. Procedure-related permanent morbidity and mortality were 0.27% (1/370) and 0%, respectively.

CONCLUSIONS

In this series of small unruptured asymptomatic aneurysms, endovascular treatment was achieved with good short-term angiographic outcome and low permanent neurologic impairment. The goal of this study was not to provide a conclusion about treatment guidelines for small UIA but rather to help guide future recommendations by presenting a more generalized estimate of endovascular treatment risk than is currently available.

High b-value diffusion (b = 3000 s/mm2) MR imaging in cerebral gliomas at 3T: visual and quantitative comparisons with b = 1000 s/mm2

BACKGROUND AND PURPOSE

High b-value diffusion-weighted imaging (DWI) provides different features not appreciated at lower b-value and have been recently studied in several clinical issues. The purpose of this study was to assess whether DWI at b = 3000 s/mm(2) is more useful in discriminating high-grade and low-grade gliomas than DWI at b = 1000 s/mm(2) at 3T.

MATERIALS AND METHODS

DWIs at both b = 1000 and 3000 s/mm(2) were performed at 3T in 62 patients, 49 high-grade gliomas (20 World Health Organization [WHO] grade III and 29 grade IV) and 13 low-grade gliomas (13 grade II). Visual assessments based on 5-point scaled evaluations, receiver operating characteristic (ROC) curve analysis, and quantitative assessment based on DWI signal intensity (SI) ratio (tumor SI/normal SI) and apparent diffusion coefficient (ADC) values were compared between DWIs at b = 1000 and 3000 s/mm(2).

RESULTS

By visual assessment, DWI at b = 3000 s/mm(2) showed more conspicuous hyperintensity in high-grade gliomas and hypointensity in low-grade gliomas than DWI at b = 1000 s/mm(2). Sensitivity and specificity at b = 3000 s/mm(2) were higher than at b = 1000 s/mm(2) (83.7%, 84.6% vs 69.4%, 76.9%, respectively). Quantitative assessments showed that mean SI ratio of high-grade gliomas was significantly higher than that of low-grade gliomas at both b-values. The mean ADC value of high-grade gliomas was significantly lower than that of low-grade gliomas at both b-values. The difference between the SI ratios of high-grade and low-grade gliomas was significantly larger at b = 3000 s/mm(2) than at b = 1000 s/mm(2).

CONCLUSION

DWI at b = 3000 s/mm(2) is more useful than DWI at b = 1000 s/mm(2) in terms of discriminating high-grade and low-grade gliomas at 3T.

A T1 hyperintense perilesional signal aids in the differentiation of a cavernous angioma from other hemorrhagic masses

BACKGROUND AND PURPOSE

A cavernous angioma is a developmental vascular malformation with a high risk of hemorrhage. The purpose of this work was to retrospectively determine whether an MR sign of T1 hyperintense perilesional signal intensity is useful for the differentiation of cavernous angioma from other hemorrhagic cerebral masses.

MATERIALS AND METHODS

The institutional review board approved this study. We retrospectively evaluated the MR images of 72 patients with acute or subacute cerebral hemorrhagic lesions with perilesional edema (29 cavernous angiomas, 13 glioblastomas, 1 oligodendroglioma, 16 metastatic tumors, and 13 intracerebral hemorrhages) for the presence of T1 hyperintense perilesional signal intensity. In addition, T1 signal intensities of a perilesional edema were quantitatively analyzed. In cavernous angiomas, volumes of hemorrhagic lesions and perilesional edemas, lesion locations, presence of contrast enhancement, and time intervals between symptom onset and MR imaging were also assessed. Data were analyzed using unpaired t test or Fisher exact test.

RESULTS

T1 hyperintense perilesional signal intensity sign was found in 18 (62.1%) of 29 cavernous angiomas, in 1 (6.3%) of 16 metastases, and in 0 primary brain tumors or intracerebral hemorrhages. Sensitivity, specificity, and positive predictive value of this sign for cavernous angioma were 62%, 98%, and 95%, respectively. The perilesional T1 hyperintensity was significantly higher in cavernous angiomas (P = .045) than in normal white matter. Perilesional edema volumes were larger in cavernous angiomas with the MR sign than in cavernous angiomas without the sign (P = .009).

CONCLUSION

When the MR sign of T1 hyperintense perilesional signal intensity is present, there is a high probability of cavernous angioma being present in the brain, and this MR sign may be helpful for differentiating cavernous angioma from hemorrhagic tumors and intracerebral hemorrhages.

Aseptic meningitis after embolization of cerebral aneurysms using hydrogel-coated coils: report of three cases

SUMMARY

We report the development of aseptic meningitis in 3 patients with aneurysms treated with hydrogel-coated coils. Patients presented with febrile meningeal syndromes during the 24 hours following the procedures and responded to corticosteroids. One of them developed delayed hydrocephalus that required treatment with a ventriculoperitoneal shunt. Aseptic meningitis is one of the important complications related to hydrogel-coated coils that should be recognized. More information based on the posttreatment surveillance after use of hydrogel-coated coils is required.

Pituitary adenoma, craniopharyngioma, and Rathke cleft cyst involving both intrasellar and suprasellar regions: differentiation using MRI

AIMS

To determine the differential magnetic resonance imaging (MRI) features of pituitary adenoma, craniopharyngioma, and Rathke cleft cyst involving both intrasellar and suprasellar regions.

MATERIALS AND METHODS

The MRI images of 64 patients with pituitary adenoma (n=38), craniopharyngioma (n=13), or Rathke cleft cyst (n=13) were retrospectively reviewed by three neuroradiologists. The following characteristics were evaluated: shape, volume, extent, component characteristics, signal intensities of solid portions on T2-weighted images, signal intensities of cystic portions on T1-weighted images, and enhancement patterns of solid portions and cyst walls of tumours. Fisher's exact test applied with Bonferroni correction was used for multiple comparison. A flowchart for differential diagnosis was constructed based on statistical analysis of the results.

RESULTS

A snowman shape, solid characteristics, and homogeneous enhancement of the solid portion were more common in pituitary adenomas (p<0.017). A superiorly lobulated shape, third ventricle compression by superior tumour extension, mixed solid and cystic characteristics, and reticular enhancement of the solid portion were more common in craniopharyngiomas (p<0.017). Finally, an ovoid shape, a small tumour volume, cystic characteristics, and no or thin cyst wall enhancement were more common in Rathke cleft cysts (p<0.017). The flowchart yielded diagnostic accuracies as follows: 92.1% in pituitary adenoma; 92.3% in craniopharyngioma; 92.3% in Rathke cleft cyst; and 92.2% overall.

CONCLUSION

A combination of MRI findings is helpful in the differential diagnosis of the three tumours involving both intrasellar and suprasellar regions.

Protection against porcine reproductive and respiratory syndrome virus (PRRSV) infection through passive transfer of PRRSV-neutralizing antibodies is dose dependent

Previous work in our laboratory demonstrated that passive transfer of porcine reproductive and respiratory syndrome virus (PRRSV)-neutralizing antibodies (NA) protected pregnant sows against reproductive failure and conferred sterilizing immunity in sows and offspring. We report here on the dose requirement for protection by passive transfer with NA in young weaned pigs. The presence of a 1:8 titer of PRRSV-NA in serum consistently protected pigs against viremia. Nevertheless, their lungs, tonsils, buffy coat cells, and peripheral lymph nodes contained replicating PRRSV similar to the infected control group. Likewise, these animals excreted infectious virus to sentinels similar to the infectivity control animals. In an attempt to reach complete protective immunity equivalent to that previously observed in sows, the pigs were transferred with a higher titer of PRRSV-NA (1:32), and even then apparent sterilizing immunity was attained in only 50% of the animals. In conclusion, the presence of anti-PRRSV-NA in serum with a titer of 1:8 is enough to block viremia but not peripheral tissue seeding and transmission to contact animals. While a relatively low level of NA in blood is capable of conferring sterilizing immunity against PRRSV in sows, the amount of NA necessary to obtain full protection of a young weaned pig would be significantly higher, suggesting that differences exist in the PRRSV pathogenesis between both age groups. In addition, the titer of NA could be a helpful parameter of protection in the assessment of PRRSV vaccines.

Embolization of wide-necked aneurysms with using three or more microcatheters

BACKGROUND

A new and relatively simple endovascular technique, in which more than three microcatheters are used for endovascular treatment of cerebral aneurysms for the first time, is described.

METHOD

Eight patients with wide necked aneurysms were successfully treated with detachable coils using the multiple microcatheter technique. Three patients presented with subarachnoid haemorrhage and five were unruptured. The aneurysm locations were superior hypophyseal artery (2), posterior communicating artery (2), middle cerebral artery bifurcation (1), distal anterior cerebral artery (1), basilar artery (1) and vertebral artery (1). The average neck size was 7.4 +/- 2.8 mm (3.5-12 mm), average width of the aneurysms was 10.6 +/- 5.7 mm (6.2-23 mm) and depth was 8.9 +/- 5.8 mm (3-22 mm). Three microcatheters (7 patients) and four microcatheters (1 patient) were introduced and used for coil delivery. Three or four coils were deployed and intermingled to stabilize the whole coil mass as well as to occupy the aneurysmal sac. When a relatively stable coil frame was formed, one coil was detached and subsequent coils were inserted. After the coil mass became more stable, other coils were also detached and all microcatheters were used for subsequent coil deployment.

FINDINGS

All aneurysms were successfully treated without complications. Postemboilzation angiograms showed no contrast filling in 5 cases (100% occlusion) and a very small residual neck in 3 cases. There was no procedure related complication.

CONCLUSION

The multiple microcatheter technique can be one technical option for the endovascular treatment of wide necked aneurysms.

Mechanically-induced proximal arterial occlusion and stent-within-a-stent technique for the treatment of bilateral vertebral artery dissecting aneurysms

Several endovascular approaches have been used in the treatment of dissecting aneurysms of the vertebrobasilar system. We present a case of a bilateral spontaneous vertebral artery (VA) dissecting aneurysms presenting with a subarachnoid haemorrhage. The dominant left VA aneurysm was treated with a stent-within-a-stent construct and the contralateral VA aneurysm was proximally occluded, with no complications, by an unintentional mechanically-induced arterial occlusion.

3T 1H-MR spectroscopy in grading of cerebral gliomas: comparison of short and intermediate echo time sequences

BACKGROUND AND PURPOSE

Echo time (TE) can have a large influence on the spectra in proton MR spectroscopy ((1)H-MR spectroscopy). The purpose of this study was to comparatively assess the diagnostic value of 3T single-voxel (1)H-MR spectroscopy with short or intermediate TEs in grading cerebral gliomas.

METHODS

Single voxel (1)H-MR spectroscopy was performed at 3T in 35 patients with cerebral glioma. The spectra were obtained with both short (35 ms) and intermediate TEs (144 ms). Metabolite ratios of choline (Cho)/creatine (Cr), Cho/N-acetylaspartate (NAA), lipid and lactate (LL)/Cr and myo-inositol (mIns)/Cr were calculated and compared between short and intermediate TEs in each grade. After receiver operating characteristic curve analysis, diagnostic accuracy for each TE in differentiating high-grade glioma from low-grade glioma was compared.

RESULTS

At short TE, Cho/Cr and Cho/NAA ratios were significantly lower, and LL/Cr and mIns/Cr were significantly higher, compared with those at intermediate TE, regardless of tumor grade. Lactate inversion at intermediate TE was found in only 2 patients. At both TEs, there were significant differences in Cho/Cr and LL/Cr ratios between low- and high-grade gliomas. Diagnostic accuracy was slightly higher at short TE alone or combined with intermediate TE than intermediate TE alone (85.7% versus 82.9%).

CONCLUSION

Metabolite ratios were significantly different between short and intermediate TE. Cho/Cr and LL/Cr ratios at either TE were similarly useful in differentiating high-grade gliomas from low-grade gliomas. If only a single spectroscopic sequence can be acquired, short TE seems preferable because of poor lactate inversion at intermediate TE on 3T single-voxel (1)H-MR spectroscopy.

Simultaneous Bilateral Carotid Stenting under the Circumstance of Neuroprotection Device. A Retrospective Analysis

SUMMARY

In this study, in order to evaluate the feasibility and outcomes of simultaneous bilateral carotid artery stenting (CAS) with the use of neuroprotection in symptomatic patients, we conducted a retrospective analysis of 27 patients (19 men, eight women; median age, 69.2 years), all of whom had been scheduled to undergo bilateral CAS in a single setting. All patients presented with severe atherosclerotic bilateral carotid stenosis (> 50% for symptomatic side, > 80% for asymptomatic side), exhibiting symptoms of either a cerebrovascular accident or of a transient ischemic attack on at least one side. 48 arteries were treated with self-expandable stents. Neuroprotection devices were utilized for bilateral CAS in 11 patients, and in 16 unilateral CAS patients. We did not perform the second procedure in six patients, in cases in which a patient exhibited (a) hemodynamic instability, (b) a new neurological impairment, or (c) restlessness after a prolonged time for the first CAS. The second procedure was postponed in a staged manner. We achieved a mean residual stenosis of 8.1 +/- 5.0 % in the treated lesions. The mean procedural time for bilateral CAS was three hours and 18 minutes. 17 patients (63%) developed transient bradycardia during the balloon dilatation of one or both of the relevant arteries. Three patients (11%) exhibited persistent bradycardia and hypotension, which required the administration of intravenous vasopressors for several days (2~7 days). None of the patients ultimately required pacemakers, or any further therapy. Two of the patients (7%) developed transient ischemic attack during the periprocedural period, but recovered completely. One patient developed a new minor stroke after the first procedure, and the second procedure was delayed in a staged manner.We observed no periprocedural deaths, major strokes, or myocardial infarctions, nor did we detect any cases of hyperperfusion syndrome within 30 days. In summary, simultaneous bilateral CAS with neuroprotection can be performed in a single setting without increased concerns with regard to hyperperfusion syndrome, hemodynamic instability, thrombo-embolism, or procedure time, when the first CAS has been safely completed with no evidence of complications in a wellmanaged procedure time.

MRI findings and spreading patterns of necrotizing external otitis: Is a poor outcome predictable?

AIM

To evaluate spreading patterns of necrotizing external otitis (NEO) by magnetic resonance imaging (MRI) and to identify spreading patterns related to a poor outcome.

MATERIALS AND METHODS

Fourteen patients with NEO were divided into good and poor outcome groups according to their final clinical outcomes. Initial MRI images were retrospectively reviewed for regional abnormalities, and follow-up MRI images were reviewed for ICA flow void abnormality and for the following five spreading patterns: medial, crossed, anterior, intracranial, and combined. The frequencies of the abnormal flow void or spreading patterns were compared between the good and poor response groups.

RESULTS

Seven (50%) and seven (50%) patients were respectively allocated to the good and poor outcome groups. Retrocondylar fat infiltration was the most commonest finding on initial MRI images (93%). The frequencies of the abnormal flow void and spreading patterns in the good and poor groups, respectively, were: abnormal flow void, 0 and four (57%); anterior, two (29%) and three (43%); medial, six (86%) and seven (100%); crossed, six (86%) and seven (100%); intracranial middle cranial fossa, one (14%) and four (57%); intracranial posterior cranial fossa, four (57%) and six (86%); intracranial foramen magnum, one (14%) and six (86%).

CONCLUSIONS

NEO almost always involves the retrocondylar fat and spreads via various pathways to extracranial or intracranial spaces. The presence of an abnormal flow void and intracranial dural enhancement, particularly in the middle cranial fossa and foramen magnum, may indicate a poor prognosis.

Kaposiform hemangioendothelioma arising from the internal auditory canal

Kaposiform hemangioendothelioma is a rare vascular tumor and locally aggressive endothelial-derived spindle cell neoplasm, which occurs almost exclusively in infants and adolescents. Radiologically, hemangioendothelioma, including Kaposiform hemangioendothelioma, is seen as a highly vascularized well-enhancing tumor, but no characteristic findings differentiate Kaposiform hemangioendothelioma from other soft-tissue tumors, particularly when the tumor is too small to have any locally aggressive features or identifiable large vessels. We present a case of Kaposiform hemangioendothelioma in the internal auditory canal that had no differential features on initial MR images and rapidly grew into a huge mass in a few months.

Clinical analysis of vertebrobasilar dissection

BACKGROUND

The natural history of vertebrobasilar artery dissection (VAD) is not fully known. The purpose of this study was to review the clinical outcome of the patients with VAD, then to propose an appropriate management strategy for VAD.

METHOD

From 1992 to 2004, 35 VAD patients admitted to our institutes were retrospectively reviewed. There were 28 men and 7 women, whose age ranged from 4 to 67 years with a mean age of 44 years. Angiography was assessed to document the shape, and location of the dissecting aneurysm with respect to the posterior inferior cerebellar artery (PICA). A modified Rankin score was assigned for functional outcome. The functional outcome scores were analyzed according to the patient's age, gender, hypertension history, the pattern of initial manifestation, angiographic shape of VAD, angiographic location of VAD, treatment modality.

FINDINGS

There was no statistically significant difference between the functional outcome with age, gender, trauma history and past medical history of hypertension. Of 35 patients, 22 presented with SAH, 11 with ischemic symptoms and 2 were incidentally detected. The patients without SAH had a better functional outcome than those with SAH (p = 0.029). There was statistical significance between Hunt-Hess (H-H) grade and clinical outcome (p = 0.032). The shape and location of VAD was not significantly related to the functional outcome (p = 0.294, 0.840). But all the cases of rebleeding and mortality (except one case with initially poor H-H grade) developed exclusively in patients with aneurysms. There was no statistically significant correlation between the treatment modality and the outcome (p = 0.691).

CONCLUSION

The VAD patients with SAH would be recommended to be managed by either surgical or endovascular treatment, but those without SAH, could be managed conservatively with antiplatelet therapy and/or anticoagulation.

Anatomical and clinical outcomes after endovascular treatment for unruptured cerebral aneurysms. A single-center experience

SUMMARY

To describe the immediate and follow-up anatomical outcomes as well as procedure-related morbidity after endovascular procedures for unruptured cerebral aneurysms, we reviewed 68 patients with 78 unruptured aneurysms treated with detachable coils from may 1996 to february 2002. Angiograms were retrospectively reviewed for the nature of the aneurysms and the degree of therapeutic obliteration. Periprocedural complications, immediate clinical outcome and longterm neurological status were analyzed. Immediate anatomical outcomes were complete in 35 aneurysms (45%); residual neck in 24 (31%), partial contrast filling in 17 (22%), and failed embolization in two (2%). Of 27 aneurysms with follow-up angiography, 12 of the 13 aneurysms that were completely occluded in the initial treatment were still completely occluded at the end of a mean follow-up period of 17 months. Periprocedural complications were thromboembolic (n=6), haemorrhagic (n=3), coil protrusion (n=7) and other unrelated complications (n=3). Only two patients, with thromboembolic complications were moderately disabled with permanent neurological deficits in immediate clinical outcome, and their condition improved to independent in 1.5 and three months each. Small aneurysms and posterior circulation location showed more protective immediate results than aneurysms of large and anterior circulation after endovascular treatment (p values: 0.01 and 0.02). Our experiences of endovascular treatment for unruptured cerebral aneurysms were comparable to the results of recent series. Endovascular treatment for small posteriorly located aneurysms produced significantly better results than for large anteriorly located lesions.

PC-Based 3D Reconstruction of MR Angiography in Evaluation of Intracranial Aneurysms. The Value of Pre-Treatment Planning for Embolization and Post-Treatment Follow-up

SUMMARY

In this study, we present our experiences of personal computer-based 3D reconstructions of MRA for pre-treatment planning and post-treatment follow-up for cerebral aneurysms. Twentynine ruptured or unruptured intracranial aneurysm patients with 36 intracranial aneurysms, who underwent embolization and pretreatment and/or follow up 3D MRA were included in this study. All 29 patients were examined by DSA and MRA before (18 patients, 24 aneurysms) and/or after embolization (16 patients, 17 aneurysms). The MRA source images were transported to a personal computer in DICOM format for viewing, post-processing, and 3D reconstruction. DSA and PC based SSD 3D MRA equally well demonstrated most aneurysms before embolization (17 patients, 22 aneurysms). The depiction of aneurysm morphology, neck evaluation and branch vessel interpretation were much easier on 3D MRA, which has the ability to manipulate images in real time. When the vascular anatomy was complicated by another vascular system, the anterior or posterior circulations were separately reconstructed easily by using PC based reconstruction software. The 3D MRA also well demonstrated post-embolization recurrence or remnant aneurysmal cavities. In one giant aneurysm, the 3D MRA was unable to show the entire aneurysmal sac due to a blood flow saturation effect, but this was resolved by additional contrast material injection. PC-based 3D MRA proved to be a useful tool for the pretreatment planning of embolization procedures and for follow up after treatment in the case of cerebral aneurysms.

Holocord myelopathy with thoracic stenosis: case report and hypothesis

STUDY DESIGN

Case report

OBJECTIVE

To examine the resolution of holocord myelopathy based on the hypothesis of altered cerebrospinal fluid (CSF) dynamics.

SETTING

Seoul National University Hospital, Seoul, Korea.

METHOD

We describe a case of thoracic stenosis with holocord myelopathy, which suggests an alternative mechanism for the myelopathy.

RESULT

Decompression of the thoracic stenosis resulted in the resolution of holocord myelopathy.

CONCLUSION

Myelopathy may be caused by altered CSF dynamics and this type of myelopathy seems to be interstitial edema. Improvement of altered CSF flow dynamics could resolve this type of myelopathy.

Procedure-related haemorrhage in embolisation of intracranial aneurysms with Guglielmi detachable coils

We reviewed the haemorrhagic complications of the endovascular treatment of intracranial aneurysms, in terms of frequency, pre-embolisation clinical status, clinical and radiological manifestations, management and prognosis. In 275 patients treated for 303 aneurysms over 7 years we had seven (one man and six women--2.3%) with haemorrhage during or immediately after endovascular treatment. All procedures were performed with a standardised protocol of heparinisation and anaesthesia. Four had ruptured aneurysms, two at the tip of the basilar artery, and one ach on the internal carotid and posterior cerebral artery, treated after 12, 5, 14, and 2 days, respectively, three were in Hunt and Hess grade 2 and one in grade 1. Bleeding occurred during coiling in three, after placement of at least four coils, and during manipulation of the guidewire to enter the aneurysm in the fourth. Haemorrhage was manifest as extravasation of contrast medium, with a sudden rise in systolic blood pressure in three patients. The other three patients had unruptured aneurysms; they had stable blood pressure and angiographic findings during the procedure, but one, under sedation, had seizures immediately after insertion of four coils, and the other two had seizures, headache and vomiting on the day following the procedure. Heparin reversal with protamine sulphate was started promptly started when bleeding was detected in four patients, and the embolisation was completed with additional coils in three. Emergency ventricular drainage was performed in the two patients with ruptured aneurysm and one with an unruptured aneurysm who had abnormal neurological responses or hydrocephalus. The bleeding caused a third nerve palsy in one patient, which might have been due to ischaemia and progressively improved.

Consonant identification under maskers with sinusoidal modulation: masking release or modulation interference?

The present study investigated the effect of envelope modulations in a background masker on consonant recognition by normal hearing listeners. It is well known that listeners understand speech better under a temporally modulated masker than under a steady masker at the same level, due to masking release. The possibility of an opposite phenomenon, modulation interference, whereby speech recognition could be degraded by a modulated masker due to interference with auditory processing of the speech envelope, was hypothesized and tested under various speech and masker conditions. It was of interest whether modulation interference for speech perception, if it were observed, could be predicted by modulation masking, as found in psychoacoustic studies using nonspeech stimuli. Results revealed that masking release measurably occurred under a variety of conditions, especially when the speech signal maintained a high degree of redundancy across several frequency bands. Modulation interference was also clearly observed under several circumstances when the speech signal did not contain a high redundancy. However, the effect of modulation interference did not follow the expected pattern from psychoacoustic modulation masking results. In conclusion, (1) both factors, modulation interference and masking release, should be accounted for whenever a background masker contains temporal fluctuations, and (2) caution needs to be taken when psychoacoustic theory on modulation masking is applied to speech recognition.

Peripheral cholangiocarcinoma with extensive tumor thrombi in the portal venous system: case report

Peripheral cholangiocarcinoma is a primary liver tumor, with some features that distinguish it from hepatocellular carcinoma, especially the low incidence of vascular involvement relative to mass size. Radiologically, tumor thrombus seen as an expanding central filling defect is a rare finding of cholangiocarcinoma on computed tomography, even though microscopic invasion or vascular encasement has been reported in a few studies. We report a case of a peripheral cholangiocarcinoma with tumor thrombus expanding and spreading from the portal vein to the superior mesenteric vein.

Immunoprophylactic effect of chicken egg yolk immunoglobulin (Ig Y) against porcine epidemic diarrhea virus (PEDV) in piglets

Porcine epidemic diarrhea virus (PEDV) is the causative agent of neonatal diarrhea in piglets, which causes high mortality rates. In this study, the immunoprophylactic effects of chicken egg yolk immunoglobulin (Ig Y) against PEDV were investigated in neonatal pigs. Ig Y was found to reduce the mortality in piglets after challenge exposures. The field application of Ig Y also revealed significant differences in survival rates of piglets given Ig Y, as compared with placebo or control. The results in this study indicated that Ig Y against PEDV could be an alternative way of supplementing prophylactic measures like colostral antibodies from sows.

Derivation of attenuated porcine epidemic diarrhea virus (PEDV) as vaccine candidate

The field isolate of porcine epidemic diarrhea virus (PEDV) was serially passaged in Vero cells. The cell passaged PEDV, designated KPEDV-9, was tested for its pathogenicity in the neonatal pigs, immunogenicity and safety in the pregnant sows. The result indicated that KPEDV-9 at the 93rd passage revealed reduced pathogenicity in the neonatal pigs. Pregnant sows inoculated with the attenuated virus showed increased immune responses by ELISA. In addition, delivered piglets were protected from challenge of wild type PEDV. The safety test in pregnant sows indicated that all inoculated animals farrowed the average numbers of litters of piglets. The results of this study supported that the attenuated virus derived from serial passage could be applied as vaccine for protecting suckling piglets against PEDV infection.

Frequency-weighting functions for broadband speech as estimated by a correlational method

The relative contributions of various regions of the frequency spectrum to speech recognition were assessed with a correlational method [K. A. Doherty and C. W. Turner, J. Acoust. Soc. Am. 100, 3769-3773 (1996)]. The speech materials employed were the 258-item set of the Nonsense Syllable Test. The speech was filtered into four frequency bands and a random level of noise was added to each band on each trial. A point biserial correlation was computed between the signal-to-noise ratio in each band on the trials and the listener's responses, and these correlations were then taken as estimates of the relative weights for each frequency band. When the four bands were presented separately, the correlations for each band were approximately equal; however, when the four bands were presented in combination, the correlations were quite different from one another, implying that in the broadband case listeners relied much more on some bands than on others. It is hypothesized that these differences reflect the way in which listeners combine and attend to speech information across various frequency regions. The frequency-weighting functions as determined by this method were highly similar across all subjects, suggesting that normal-hearing listeners use similar frequency-weighting strategies in recognizing speech.