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Background: Assessment of plaque vulnerability is important in evaluating the future risk of stroke. Plaque characteristics and plaque volume are important components of plaque vulnerability. Expansive remodeling (ER) is one of the criteria for vulnerable plaque in the coronary arteries, and influences the plaque volume. The aim of this study is risk stratification of carotid plaque through the evaluation of quantitative ER and MRI plaque signal intensity. Methods: We studied and obtained both pre-operation carotid MRI T1-weighted axial and long axis images of 72 patients who underwent carotid endarterectomy or carotid aretery stenting. ER ratio (ERR) was calculated from the ratio of the linear diameter of the artery at the thickest segment of the plaque to the diameter of the artery beyond any poststenotic dilatation on the long axis image on carotid MRI. We also calculated relative plaque signal intensity (rSI) from the axial image and grouped the patients as follows: Group A, rSI≥1.4 and ERR≥1.8; Group B, rSI Results: Of the 72 patientis, the number of patients in each group was as follows: Group A, 20 patients; B, 12 patients; C, 19 patients; D, 21 patients. Fifteen patients (75%) in Group A, 6 patients (50%) in Group B, 8 patients (42%) in Group C and 7 patients (33%) in Group D had ischemic events within 6 months. Ischemic events in Group A was significantly higher than in Group C and D (p Conclusion: The combined assessment of plaque characterization with MRI and morphological evaluation using ERR are useful in risk stratification for carotid lesions.

Carotid artery stenting (CAS) has been covered by the health insurance system in Japan since 2008. There have been few studies concerning medical costs and charges for patients who received CEA or CAS in Japan. The aim of this study was to elucidate the difference in the costs between the patients who received CEA and those who received CAS in Japan. Between 2010 and 2011, 19 patients who received CEA and 20 patients who received CAS were retrospectively reviewed. Age, sex, symptomatic/asymptomatic, emergent/scheduled, length of stay, outcome, cost for the procedure (professional fee), supply for the operation, the total medical service fee, and copayment of the patients was compared between the two treatment groups. No significant difference was detected between the two groups except for the supply of the operation and the total medical service fee (CEA:mean 1,565,580 yen vs CAS 2,758,360 yen, p=0.0001). On the other hand, no significant difference was obtained in the copayment of the patients (CEA 71,895 yen, CAS 72,458 yen). Even when limited to the scheduled cases, similar results were obtained. There is a monthly copayment limit in the health insurance system in Japan, which results in a reasonable charge for patients who received CAS, despite the fact that the rest of the fee including high costs for the supplies was paid by the company and the nation. To reduce the medical costs, Japanese have to be aware of the high costs in CAS, most of which is due to the supplies.

Perimesencephalic nonaneurysmal subarachnoid hemorrhage (PNSAH) is a benign form of subarachnoid hemorrhage and is usually not associated with any focal deficit. We describe two rare cases of PNSAH with unilateral third cranial nerve palsy. Both patients were treated conservatively. The outcomes of our two cases were excellent. The third cranial nerve palsy resolved gradually in both patients, suggesting that the prognosis for third cranial nerve palsy concomitant with PNSAH is favorable. Unilateral third cranial nerve palsy may occur as the first clinical manifestation of PNSAH.

Ischemia-induced changes in neurotransmitter release and their mechanisms were examined using cultured bovine adrenal chromaffin cells. When the cells were incubated in glucose-free media equilibrated with 0% O 2 /100% N 2 (ischemia), ATP content decreased and reached the minimum level within 40 min. Control incubation was done in media equilibrated with 21% O 2 in N 2 . After 10-min incubation under ischemic conditions, basal catecholamine (CA) release was elevated and the elevation persisted up to 90 min. High K + -evoked CA release was transiently enhanced at 10 min, but after that, it decreased to reach the minimum level at 60 min. At 10 min, cytosolic free Ca 2+ concentration ([Ca 2+ ] i ) and 45 Ca 2+ uptake of the resting cells (basal values) and high K + -evoked increases in these two parameters were unchanged, but CA release from permeabilized cells in response to Ca 2+ in media was augmented. After 60-min incubation under ischemic conditions, basal [Ca 2+ ] i was elevated: the elevation was observed even in the absence of extracellular Ca 2+ . In contrast, high K + -evoked increases in [Ca 2+ ] i and in 45 Ca 2+ uptake were suppressed, but basal 45 Ca 2+ uptake into intact cells and CA release from permeabilized cells were unchanged. These results suggest that in an early phase (10 min) of ischemia, both basal and stimulation-evoked CA release are augmented because of increased sensitivity of exocytotic machinery to Ca 2+ . In a late phase (60 min), basal CA release is augmented because of an increase in basal [Ca 2+ ] i , which is due to accumulation of Ca 2+ derived from intracellular Ca 2+ pools: stimulation-evoked CA release is suppressed because of inhibition of stimulation-evoked increase in [Ca 2+ ] i , which is due to functional disturbance of voltage-dependent Ca 2+ channels.

There is a lack of evidence to compare in-hospital mortality with different types of stroke. The purpose of this study was to elucidate the in-hospital mortality after acute ischemic/hemorrhagic stroke and compare the factors associated with the mortality among stroke subtypes. All patients admitted to Kurashiki Central Hospital in Japan between January 2009 and December 2009, and diagnosed with acute ischemic/hemorrhagic stroke were included in this study. Demographics and clinical data pertaining to the patients were obtained from their medical records. Out of 738 patients who had an acute stroke, 53 (7.2%) died in the hospital. The in-hospital mortality was significantly lower in the cerebral infarction group than in the intracerebral hemorrhage and subarachnoid hemorrhage group (3.5%, 15.1%, and 17.9%, respectively; P0.0001). Age was significantly lower in the subarachnoid hemorrhage group than in the other 2 groups. With regard to past history, diabetes mellitus was significantly found to be a complication in mortality cases of intracranial hemorrhage. Further investigation is needed to clarify the effect of diabetes on mortality after intracranial hemorrhage.

Background To investigate stroke incidence and rate of thrombolytic therapy in an urban city of around 500,000 residents. Methods Patients suffering acute stroke in Kurashiki City (population 474,415) between March 2009 and February 2010 (inclusive) and admitted to 1 of 10 hospitals throughout the city were prospectively enrolled. Results We enrolled patients with first-ever stroke (n = 763; men 415; median age 72 years) and first-ever/recurrent stroke (n = 1009; men 552; median age 73 years). Among first-ever strokes, 68% were cerebral infarctions, 23% were intracerebral hemorrhages, and 8% were subarachnoid hemorrhages. Crude incidences for first-ever stroke per 100,000 residents were 159.8 (95% confidence interval [CI] 148.4-171.1) for all strokes, 108.8 (95% CI 99.4-118.1) for cerebral infarction, and 36.5 (95% CI 31.0-41.9) for intracerebral hemorrhage. After adjustment using the world population model, age-adjusted incidences were 60.7 (95% CI 45.4-75.9) for all strokes, 38.4 (95% CI 26.3-50.5) for cerebral infarction, and 16.1 (95% CI 8.3-24.0) for intracerebral hemorrhage. Among 698 cases with first-ever and recurrent cerebral infarction, thrombolysis was administered for 31 (5%). Of 197 cerebral infarction patients admitted within 3 hours of onset, the thrombolysis rate was 16%. Conclusion In this urban Japanese city, the age-adjusted incidence of first-ever stroke between March 2009 and February 2010 was 60.7 per 100,000 residents, which was relatively low compared with findings for other countries. Thrombolysis was given to approximately 5% of patients with acute ischemic stroke.

Variant deep cerebral venous drainage, primarily involving the basal vein of Rosenthal (BVR), may be a cause of idiopathic subarachnoid hemorrhage (SAH). In this study, deep venous drainage was compared between 13 patients with idiopathic SAH and 35 control patients with aneurysmal SAH diagnosed by digital subtraction angiography (DSA). Venous return was evaluated by DSA on 25 sides in patients with idiopathic SAH and 67 sides in patients with aneurysmal SAH, and the relationship between the BVR and the vein of Galen was classified into 3 categories: types A (normal continuous), B (normal discontinuous), and C (primitive variant). The occurrence rates of the three categories were: idiopathic SAH, type A 24%, type C 40%; and aneurysmal SAH, type A 49.3%, type C 10.4% (p = 0.003). Combined bilateral venous drainage was classified as normal combination (AA), discontinuous combination (AB, BB), and primitive combination (AC, BC, CC), with rates: idiopathic SAH, normal 0%, primitive 58.3%; and aneurysmal SAH, normal 42.4%, primitive 21.2%. Venous drainage on either the left or right side was more commonly type C (primitive) in idiopathic SAH (p = 0.006). Three patients with left-right differences in hematoma distribution on brain computed tomography had types A, B, and C on the SAH dominant side in one patient each. No clear trend was observed between hematoma distribution and primitive variant side. Some patients with idiopathic SAH had thick hematoma in the basal cistern. Further, 3 patients with idiopathic SAH had an aneurysmal pattern, rather than a perimesencephalic pattern. All these patients had type C either on the left or right side. Therefore, although the mechanism of involvement of venous drainage in idiopathic SAH is unknown, hemorrhage is not limited to a perimesencephalic pattern. The present findings support a previous hypothesis that variant venous drainage is involved in the occurrence of idiopathic SAH. The absence of a normal combination of venous drainage is an important factor to diagnose idiopathic SAH.

We retrospectively reviewed the mortality rate of the patients with subarachnoid hemorrhage (SAH) who received initial treatment in Kurashiki Central Hospital, for the 10-year period from 1999 through 2008. The overall mortality was 18.1% (120/662). The average fatality rate in such cases has shown a decreasing trend, from 24.2% in 1999-2002 to 15.9% in 2005-2008 (p=0.016). Transition in initial diagnostic modality from the time-consuming digital subtraction angiography to the less-invasive computed tomographic angiography, appropriate indication for the operation, and improvement in postoperative management might affect this decline in fatality cases.

The optimal therapeutic approach for chronic carotid occlusion with contralateral carotid stenosis (ICO-ICS) remains uncertain. The aim of this study was to elucidate the safety and efficacy of initial vascular reconstruction for ICS in patients with ICO-ICS.Eleven patients with ICO-ICS who demonstrated severe cerebral hypoperfusion in the hemisphere ipsilateral to ICO were treated in our institution between February 2003 and November 2007. Revascularization for ICS after measuring cerebral blood flow (CBF) by single photon emission computed tomography (SPECT) was performed either by carotid endarterectomy or carotid stenting. External carotid artery-internal carotid artery (EC-IC) bypass for ICO was also performed when SPECT after revascularization for ICS still demonstrated marked hypoperfusion.In 6 patients with collateral flow via the anterior communicating artery and/or who had high-grade ICS (70%), sufficient improvement of CBF solely by revascularization for ICS was confirmed. With regard to perioperative complications, 2 patients suffered bradycardia and hypotension and another 2 showed asymptomatic cerebral infarction on diffusion-weighted magnetic resonance imaging.Overall results for revascularization of ICS prior to that for ICO in patients with ICO-ICS were acceptable. CBF of bilateral hemispheres was sufficiently improved in more than half of the patients solely by revascularization for ICS. This strategy might be both efficient and effective for ICO-ICS.

Microvascular surgery for the reconstruction of the graft artery has been used since the 8th case in our series of 14 liver transplantations using living-related donors, and the clinical results have been compared between the first seven cases (the Loupe group) and the last seven cases (the Micro group). Seven arteries in 7 grafts were reconstructed with the use of loupe magnification in the Loupe group, while 8 arteries in 7 grafts were anastomosed with microscopic techniques in the Micro group. Statistically, there was no difference between the two groups in general background, including age, body weight and primary disease of the recipient, and in medical and surgical factors possibly relating to postoperative thrombosis of the hepatic artery. In two cases in the Loupe group, one or two additional reconstructions were necessary to obtain sufficient blood flow, while 8 arteries were anastomosed in the Micro group without any arterial complication in the postoperative period. There was no difference in time required for completing the arterial reconstruction (45.1 +/- 18.1 min in the Loupe versus 44.4 +/- 6.9 min in the Micro [mean +/- SEM]). Postoperative ultrasonic Doppler duplex study demonstrated a temporary decrease in the arterial flow in 2 cases of the Loupe group, and partial thrombosis of the artery was suspected. Additionally there were two episodes of hepatic artery thrombosis in 1 case of the Loupe group, in which emergent revision for thrombectomy and reanastomosis was performed at the first episode. This illustrated the higher incidence of arterial complications in the Loupe group compared with the Micro group (4 episodes/7 arteries in the Loupe versus 0/8 arteries in the Micro, P less than 0.05). In the present series there were no graft failures or arterial complications in the three deaths in the series. The clinical improvements achieved by microvascular surgery in living-donor liver transplantation suggest an alternative technical strategy for dealing with problematic arterial reconstruction in adult liver transplantation.

The evaluation of plaque characteritics as well as the degree of luminal narrowing is important in the management of carotid stenosis. Several reports have shown that intraplaque hemorrhage (IPH), which plays a pivotal role in plaque vulnerability, emits high signal intensity on T1-weighted images of high-resolution black-blood (BB) MRIs. When an MRI is used to screen for vulnerable plaque, a short scanning duration and a simple MRI protocol are required. This study assessed the utility of screening BB-MRI to detect IPH. Ninety-three consecutive cases with atherosclerotic carotid stenosis scheduled for carotid endarterectomy (CEA) or carotid artery stenting between January 2005 and December 2007 were included. High-resolution BB-MRI scans were obtained with 2D double-inversion recovery fast spin-echo sequences with cardiac gating. Screening BB-MRIs were performed with 3D gradient-echo sequences suppressing blood flow signals by radiofrequency wave spatial saturation over the scanning field of 3D time-of-flight MRA. The relative overall plaque signal intensities with reference to the sternocleidomastoid muscle were calculated, and the correlation of intensities on T1-weighted images between high-resolution BB-MRI and screening BB-MRI was investigated. We excluded 50 cases because of restenosis following CEA, use of a pacemaker, a long interval (10 days) between high-resolution and screening BB-MRI examinations, or poor-quality images. Among the 43 cases included, the relative overall plaque signal intensity of high-resolution BB-MRI and screening BB-MRI were closely correlated (r = 0.568, p0.001). Screening BB-MRI can be an alternative to high-resolution BB-MRI in the assessment of IPH and may be a useful tool for detection of vulnerable plaque.

Recent diffusion-weighted imaging (DWI) studies describe a relevant ischemic lesion in almost half of all patients with transient ischemic attack (TIA). We report 3 cases of TIA in which the ischemic lesions were recognized on DWI at a later date ("late-imaged TIA"). Three men (average age, 72.7 years) were admitted to our hospital on complains of monoparesis or sensory disturbance in their right arms. On admission, no apparent ischemic lesion was detected by DWI; however, spotty lesions were apparent in the left precentral or postcentral gyrus on hospital days 2-5. The neurological symptoms resolved within 24 hours, and all the cases were clinically diagnosed as TIA. Carotid MRI revealed low-grade stenosis of the left internal carotid artery with atherosclerotic plaque, characterized as so-called "vulnerable plaque". These findings suggest that the carotid atherosclerotic plaque lead to artery-to-artery embolism. Carotid MRI is considered useful as an adjunct to other imaging modalities in the diagnosis of late-imaged TIA.

Endovascular angioplasty for subclavian artery stenosis is effective and less invasive than other methods; however, it is difficult to advance guidewires or balloon catheters through severely stenotic lesions. We report a case of subclavian artery stenosis treated with excimer laser angioplasty. A 58-year-old man with hypertension and hyperlipidemia was admitted to a hospital with different blood pressure in each arm. A CT scan revealed left subclavian artery stenosis, and the patient was transferred to our hospital. An angiogram revealed a severely stenotic lesion in his left subclavian artery, representing subclavian steal phenomenon. Endovascular angioplasty was performed under local anesthesia with embolic protection for the left vertebral artery. The guidewire successfully crossed the lesion, and stepwise balloon angioplasty was performed using increasing balloon sizes from 1.5 to 2.0 mm; however, the next size balloon catheter could not cross the lesion, and we therefore decided to use an excimer laser catheter. After laser ablation, revascularization was performed via stent placement. The patient's symptoms and subclavian steal phenomenon improved, and the post-operative course was uneventful. Excimer laser angioplasty appears to be effective in the treatment of occlusive lesions that cannot be crossed using a balloon catheter.

Purpose To investigate whether the vessel wall MRI of carotid arteries would differentiate at-risk soft plaque from solid fibrous plaque by identifying liquid components more accurately than color Doppler ultrasonography (US). Materials and Methods This study included 54 carotid arteries in 54 consecutive patients who underwent carotid endarterectomy. MRI was performed using black-blood fat-suppressed (FS) T1-and FS T2-weighted TSE sequences. A total of 68 major segments of the 54 carotid plaques were grouped into four MR categories based on signal intensity index (SII). MR criteria used for the diagnosis of plaque vulnerability were: at-risk soft plaque including a segment of liquid component (category A or B), solid fibrous plaque (category C or D). The MR and US findings were compared with histopathological findings of endarterectomy specimens. Results Intraoperative findings and microscopic examination of endarterectomy specimens revealed 24 at-risk soft plaques and 30 solid fibrous plaques. The sensitivity, specificity, and accuracy for diagnosing at-risk soft plaque are 96%, 93%, and 94% for MR, and 75%, 63%, and 69% for color Doppler US, respectively. The slice-by-slice MR evaluation of carotid wall also revealed detailed information of plaque segments and correlated well with the features of corresponding histologic sections. Conclusion Vessel wall MRI with MRI category could have a potential to more accurately diagnose an at-risk soft plaque predominantly composed of liquid components in comparison with color Doppler US. J. Magn. Reson. Imaging 2008;28:478–485. © 2008 Wiley-Liss, Inc.

To investigate the value of direct measurement of the rate constants by performing 18F-labeled fluorodeoxyglucose (FDG) studies of glucose consumption in human gliomas in vivo, a kinetic method with 3- and 4-parameter rate constant models for FDG uptake was used to analyze data from dynamic scans obtained by positron emission tomography after injection of FDG into 14 patients with glioma. The results were compared with those obtained by the autoradiographic method using 3- and 4-parameter rate constant models. There were no significant differences in the glucose consumption calculated by the four different methods both in the gliomas and in the contralateral intact cortex. It was found that the rate constant k4* could be neglected in calculation of glucose consumption in gliomas as well as in the contralateral intact cortex. The rate constant k3*, an index of hexokinase function, was higher in malignant gliomas than in benign gliomas and was close to that in the contralateral cortex. This study indicates that the 3-parameter autoradiographic method, which is the most common one used in clinical practice, is reliable for the calculation of glucose consumption in human gliomas. Furthermore, direct measurement of the regional rate constants for FDG by the kinetic method was found to be useful for evaluation of the biochemical and physiological characteristics of human gliomas in vivo.

Object. Although a pre-temporal approach (PA) can provide a wide space for preservation of thalamoperforating atrteries in direct surgery for basilar bifurcation aneurysms (BBAs), it cannot always secure adequate proximal control. The authors described the advantages of plical resection added to PA for BBAs. Methods. Between October 1998 and April 2000, eight consecutive patients with BBAs were treated in the neurosurgical department of Kurashiki Central Hospital. Among them, five patients received direct clipping using this method. There were four females and one male, ages ranging from 61 to 77 (mean 70.8 years). Mean aneurysmal size and distance between the in"terclinoidal line and the aneurysmal neck was 4.5 and 9.5 mm, respectively. The operative procedures consisted of the following components; 1) fronto-temporal craniotomy with translocation of orbito-zygomatico-malar bone for PA, 2) preservation of lateral branches of the superficial sylvian veins, 3) resection of plica dural folds to increase the operative field up to the oculomotor nerve (OMN). Results. Complete clipping was achieved without thalamic infarction or temporal contusion in all patients. Three of the five patients suffered from transient right OMN palsy which recovered within two months after surgery. Conclusion. Plical resection in the pre-temporal approach might be beneficial in the surgical treatment of BBAs when proximal control seems difficult.

Although, the overall treatment results in aneurysmal subarachnoid hemorrhage (SAH) has been improving in recent years, more than 10% of the patients with WFNS grade I and II we have sought to determine the clinical variables for predicting poor functional outcome and symptomatic vasospasm (VS) in patients with individual WFNS grades.The eligible patient fulfilled the following conditions; (1) ruptured aneurysm located in the anterior part of the circle of Willis, (2) surgically clipped followed by craniotomy under microscope, (3) early surgery within 72 hours, (4) classified to WFNS grade I or II. The medical records were retrospectively reviewed in 119 patients (63 of grade I and 56 of grade II). Sex, age, Fisher's CT group, intraventricular hemorrhage (IVH), site of aneurysm, VS, hydrocephalus, premature bleeding and complications of various kinds were selected as the dependent variables. The contributions of these factors to outcome (Glasgow Outcome Scale, GOS) as well as VS were analyzed using the logistic regression method.Outcome was better in WFNS grade I (p=0.039), and VS occurred less often and responded well to various interventional techniques and drug delivery. No significant variables contributed to the poor outcome or VS in WFNS grade I. In WFNS grade II, logistic regression analysis showed that VS (OR 34.6, 95% CI, 30.8-38.9, p =0.012) and the complications (OR 52.4, 95% CI, 46.5-59.1, p=0.004) were significant predictors for a poor outcome. Fisher's group 3 was also the only significant factors in VS (OR 3.78, 95% CI, 3.35-4.28, p =0.039). The cause for the difference in outcome and VS were discussed in detail.The vasospasm and various kinds of complications were the predictive factors of poor clinical outcome, in patient of WFNS garde II. Therefore, careful management and meticulous/pertinent surgical maneuvers are mandatory to obtain better results in aneurysmal SAH, even in better WFNS grades.

A 59-year-old healthy woman presented with sudden onset of severe headache. Computed tomography and digital subtraction angiography (DSA) demonstrated subarachnoid hemorrhage (grade I according to the Hunt and Hess classification) due to a ruptured small right posterior cerebral artery (PCA) aneurysm. The ruptured PCA aneurysm was completely embolized with three Guglielmi detachable coils (GDCs). However, follow-up DSA 3 months after the initial coiling confirmed refilling of the aneurysm. The aneurysm was successfully re-embolized with two GDCs. Follow-up DSA 10 months later revealed regrowth of the aneurysm. Surgical clipping was performed without compromising the parent vessels. Long-term angiographic follow up is necessary even in patients with small saccular aneurysms which are apparently completely embolized by endovascular coil treatment.

Management of atherosclerotic carotid arteries requires both plaque characterization and determination of the degree of stenosis, especially when carotid stenting (CAS) is being considered for severe carotid stenosis. Recent studies have demonstrated that high-resolution MRI can identify plaque components, such as the lipid-rich necrotic core, intraplaque hemorrhage, fibrous tissue, and the calcification present in human carotid atherosclerosis. The purpose of this study was to assess the feasibility of black blood MRI (BB-MRI) for accurately identifying the plaque components in vivo. Twenty-six consecutive patients scheduled for carotid endarterectomy (CEA) underwent a BB-MRI examination within 2 weeks before the surgical procedure using a 1.5-T Philips scanner with a protocol that generated 2 contrast weightings (T1 and T2). The MR images were acquired using cardiac gating to minimize motion artifact and fat suppression to reduce MR signals from subcutaneous fatty tissue. The plaque evaluations obtained by BB-MRI were compared with the intra-operative video recordings, the excised specimens, and the histological sections. With BB-MRI, the combination of the signal intensities in the T1- and T2-weighted images for each component (lipid deposits, intra-plaque hemorrhage, fibrous plaque, and calcification) showed findings that corresponded with the excised specimens. Complex morphological features could also be assessed by BB-MRI. BB-MRI is a useful method for noninvasively imaging and characterizing atherosclerotic carotid arteries. This MRI technique can provide valuable information that can be used to decide whether to perform a CEA or a CAS in patients with severe carotid stenosis. Furthermore, BB-MRI appears to be a useful tool for the investigation of the pathogenesis and natural history of carotid atherosclerosis.

Cerebral vasospasm remains a leading cause of morbidity and increasing mortality rates following aneurysmal subarachnoid hemorrhage (SAH). The rate of vasospasm and the outcome (Glasgow Outcome Scale; GOS) especially in poor WFNS grade were retrospectively analyzed over a 6-year period. Patients were divided into three different groups. The first group (pre-group) consisted of 43 patients (grade IV: 31, grade V: 12), who were admitted between 1996 and 1998. When vasospasm occurred, they were mainly treated by papaverine (PPV) and percutaneous transluminal angioplasty (PTA). In the second group (mil-cis group), for the prevention of vasospasm, cisternal irrigation therapy with milrinone was applied in 24 patients (grade IV: 13, grade V: 11), who were admitted in the period between 1999 and 2001. The third group, (w/o mil-cis group), consisted of 30 patients (grade IV: 15, grade V: 15), in whom cisternal irrigation therapy was not able to be carried out. In grade IV, vasospasm was observed in 66% of the patients the first group, 50% in the w/o mil-cis group and significantly less in the mil-cis group (15%, p0.024). In grade V, the rate of vasospasm was also lower in the mil-cis group but no statistical significance was revealed. Although the rate of favorable outcome in GOS was highest and the rate of death was least in the mil-cis group in both grade IV and V, only the trend was observed. Many factors should be considered, Cisternal irrigation therapy with milrinone reduced the occurrence of vasospasm. However, outcome was not improved because of the initial poor clinical condition.

A case of intracranial bilateral vertebral artery (VA) dissection presenting with ischemic symptoms which following unilateral dissection is presented. A 42-year-old male with an occipital headache was pointed out right vertebral artery stenosis with magnetic resonance (MR) angiography 8 day before admission. He admitted to our hospital complaining of severe vertigo and tinnitus. MR images and cerebral angiograms revealed bilateral VA dissection with infarcts in light lower surface of cerebellum perfused by posterior inferior cerebellar artery and right hypothalamus. Conservative therapy was adopted and serial MR angiography was performed. His symptoms were improved gradually and MR angiograms obtained 2 months later revealed improvement of bilateral VA stenosis. It is generally accepted that VA dissection presenting ischemic symptoms has good outcome by conservative therapy only. However, its pathological process of progression is still unknown. Based on the serial MR findings, we discuss the mechanisms of bilateral VA dissection. In this case, we consider that unilateral VA dissection extended to contralateral vertebral artery through the vertebrobasilar junction. Frequent MR angiography in acute phase could be of great use for monitoring the progression of dissection.

A 67-year-old man died of subarachnoid hemorrhage (SAH) resulting from dissection of the distal part of the anterior cerebral artery (ACA). A saccular aneurysm in the anterior communicating artery had ruptured and was successfully clipped on Day 0. The patient recovered consciousness after surgery but his condition deteriorated due to another SAH on Day 1. A second surgical procedure disclosed bleeding from a laceration in the opposite wall of the ACA distal to the clipped aneurysm. Histological examination of the autopsy specimens revealed damage to the internal elastic lamina and inflammatory infiltration of leukocytes. The fatal dissection may have resulted from atherosclerosis, hemodynamic stress caused by hypertension, or trauma due to surgical manipulation.

ness around her mouth and right arm. Computerized tomography scanning revealed hydrocephalus and a large cyst in the posterior fossa. Magnetic resonance imaging revealed that the cyst was invaginating the cervical canal and that there was a syrinx at C3–T7. A suboccipital craniectomy and a laminectomy of the atlas were performed and the cyst was found not to communicate with the fourth ventricle. A cystoperitoneal (CP) shunt was placed without direct manipulation of the syrinx. The patient’s symptoms disappeared postoperatively and both the cyst and the syrinx were significantly reduced by 1 postoperative month (Fig. 1). Case 2. This 7-year-old boy with scoliosis presented with hypesthesia in his chest. Magnetic resonance imaging revealed a syrinx in the cervical and thoracic spinal cord. A large arachnoid cyst was incidentally found invaginating the cervical canal. In this case only placement of a CP shunt was performed. After the operation, the patient’s hypesthesia was not improved but the syrinx was successfully collapsed (Fig. 2). There are several causes for the development of syringomyelia.2 However, cases associated with a posterior fossa cyst have rarely been reported.1,4 Characteristically, almost all cysts invaginate the cervical canal. These situations are very similar to tonsillar herniation in Chiari malformation.3 In the two cases outlined, we believe that the cyst invaginated the spinal canal, disturbing the circulation of the cerebrospinal fluid around the foramen magnum and thus causing the syringomyelia. The fact that in both cases the syrinx completely disappeared after posterior fossa decompression without direct manipulation of the syrinx supports our hypothesis. As in the case of syringomyelia with Chiari malformation, we recommend simple decompression of the foramen magnum as the first choice. Furthermore, investigation of the posterior fossa should be included in a case of syringomyelia.

A case of treatment-related leukoencephalopathy is presented. A patient with medulloblastoma was postoperatively treated with craniospinal axis irradiation. One month after irradiation, weekly intrathecal administration of methotrexate was performed 4 times to treat cerebrospinal fluid dissemination of the tumor. Two months after the initiation of intrathecal chemotherapy, the patient became somnolent and developed decerebrate posturing. Magnetic resonance imaging showed diffuse leukoencephalopathy. Positron emission tomography revealed a diffuse decrease in glucose uptake in the deep white matter. Auditory evoked potential also showed diffuse abnormalities, not only in the cerebrum, but also in the brain stem. High dose intravenous leucovorin rescue was attempted without any neurologic improvement.

To clarify functional changes of dopaminergic neurons and dopamine (DA) reuptake during and after ischemia, extracellular DA levels in striatum were determined using in vivo brain microdialysis in a 4-vessel occlusion model of male Wistar rats with and without pharmacological interventions. Without interventions, the extracellular DA levels markedly increased during ischemia, but upon reperfusion, rapidly returned to control level. Infusion of tetrodotoxin, a blocker of voltage-dependent Na+ channels, was without effect on the DA surge during ischemia, but decreased the DA levels after reperfusion to the same extent as in control rats. Pretreatment with nomifensine, an inhibitor of DA reuptake, was also without effect on the surge, but reduced the rate of DA decline after reperfusion to one-fifth of the rate without the pretreatment. When nomifensine was administered 40 min after reperfusion, extracellular DA levels increased to the same extent as in control rats. Infusion of high K+ 1 h after reperfusion induced a smaller increase in extracellular DA levels than that in control rats. It took 96 h for this reduced response to high K+ stimulation to recover after reperfusion. These results suggest that the DA surge during ischemia is mainly derived from action potential-independent DA release (means dysfunction of dopaminergic neurons), although activity of DA reuptake is completely inhibited. After reperfusion, the basal function of dopaminergic neurons and activity of DA reuptake rapidly recover, but the neurons are functionally disturbed to release less DA in response to a given stimulus for several days.

The purpose of the present study is to clarify the effects of hypoxia on the activity of the dopaminergic neurons in the brain and its mechanism of action. For this purpose, the effects of hypoxia on the extracellular levels of 3,4-dihydroxyphenylethylamine (dopamine) were examined in the rat striatum using in vivo brain microdialysis in the presence or absence of pretreatment with either tetrodotoxin (a blocker of voltage-dependent sodium channels) or nomifensine (a blocker of dopamine reuptake). Exposure to various degrees of hypoxia (15, 10, and 8% O2 in N2) increased dopamine levels in striatal dialysates to 200, 400, and 1,100%, respectively, of the control value. On reoxygenation, dopamine levels in the dialysates rapidly returned to the control level. Reexposure to hypoxia increased the dopamine levels to the same extent as during the first exposure. After addition of tetrodotoxin (40 microM) to the perfusion fluid or pretreatment with nomifensine (100 mg/kg, i.p.), exposure to hypoxia no longer increased the dopamine levels. These results suggest that although hypoxia induces an increase in the extracellular dopamine levels (hence, an apparent increase in the activity of the dopaminergic neurons), this increase is not the result of an increase in dopamine release itself, but rather the result of inhibition of the dopamine reuptake mechanism.

✓ A case of Cobb's syndrome, which is characterized by spinal and vertebral angiomas and a skin nevus at the same metameric level, is reported. The spinal angiomas were treated with liquid embolization using ethylene vinyl alcohol.

A case of an unruptured giant aneurysm of the cavernous portion of the left internal carotid artery associated with a persistent primitive trigeminal artery (PTA) is presented. The usual surgical approach to giant aneurysms at this site. including ligation of the ipsilateral internal carotid artery (ICA) and an extracranial-intracranial (EC-IC) bypass, was inadequate because of continued blood supply to the aneurysm via the PTA from the vertebrobasilar system. The patient was successfully treated with a combination of EC-IC bypass surgery, ICA ligation, and simultaneous intravascular balloon obliteration of the ICA just distal to the junction of the PTA and immediately proximal to the aneurysmal neck. Follow-up radiological investigations showed thrombosis of the aneurysm.

The authors are presenting two patients with subclavian steal syndrome successfully treated by axillo-axillary bypass or by percutaneous transluminal angioplasty, and discuss the choice of procedures for the correction of the subclavian steal syndrome. The first patient was a 48-year-old man complaining of easy fatiguability of the right arm and vertigo. No neurological abnormality was found, but the blood pressure was 160/90 mmHg in the left arm and 120⁄90 in the right. Angiograms revealed complete occlusion of the innominate artery and retrograde filling of the right vertebral artery. Axillo-axillary bypass was performed using 8F Dacron velour graft under general anesthesia. After surgery, the patient was free from any symptoms and the patent axillo-axillary bypass and antegrade flow of right vertebral artery were observed on postoperative angiograms. The second patient was a 58-year-old man who experienced an episode of motor weakness of the left upper and lower extremities and speech disturbance 8 years before admission. Although neurological examination was within normal limits except for a slight left hemiparesis and there was no difference between the blood pressure values measured in either arm, angiograms showed complete occlusion of the left subclavian artery at the proximal portion and a moderate stenosis at the distal portion as well as retrograde filling of the left vertebral artery. Following angiography, percutaneous transluminal angioplasty was performed at the occlusive and stenotic portions. Recanalization of the occluded proximal subclavian artery with smooth vessel wall contours and reduction of a stenosis at the distal portion were observed in the postangioplasty angiograms. It is suggested that percutaneous transluminal angioplasty can be safely applied to occlusive lesions of the left subclavian artery with the retrograde flow of the left vertebral artery.

In an investigation of the changes in cerebral blood flow (CBF) in subarachnoid hemorrhage, CBF was monitored in 14 patients who underwent surgery within 3 days of the onset of hemorrhage. On admission, one patient was neurological grade I, one was grade II, seven were grade III, and five were grade IV. Computed tomography showed diffuse, thick subarachnoid hemorrhage with or without intracerebral hematoma in all patients, strongly indicating the possibility of cerebral vasospasm. CBF monitoring was performed by the thermal diffusion technique, in which a small flow probe, 7 mm in diameter and 4 mm in height and containing a Peltier stack, is used. The probe was implanted in the subdural space in the frontotemporal region during surgery. Epidural intracranial pressure was also monitored. Local CBF was measured continuously for 7 to 19 days after surgery. Immediately after surgery, CBF was low in grade IV patients (mean, 25 ml/100 g/min), whereas a variety of CBF rates were observed in grade III patients. Minimal decreases in CBF were noted in the grades I and II patients (mean, 41 ml/100 g/min). The sequential changes in CBF were well correlated with outcome. The two grades I and II patients, who had no appreciable decrease in CBF, had excellent outcomes. In the five (of seven) grade III patients who showed good or excellent recovery, CBF was maintained with only a slight decrease. In two grade III patients, substantial depression of CBF occurred several days after the onset of subarachnoid hemorrhage; one had a poor outcome, and one died. Good recovery of CBF was observed in one grade IV patient, who showed excellent postoperative recovery. The remaining four patients, had moderate to substantial decreases in CBF, with poor postoperative results, including two deaths. These observations indicate that a decrease in CBF due to vasospasm or other causes can be detected early through CBF monitoring. In addition, the outcome of subarachnoid hemorrhage can be predicted on the basis of sequential changes in CBF.

Blood compatibility has been studied for hydrophilic polymers such as poly(vinyl alcohol) (PVA), its derivative, and polyethylene grafted with water-soluble monomers. The surfaces in contact with electrolyte solutions have been characterized by measuring the zeta potentials. The study of plasma protein adsorption on these polymers has revealed that bovine serum albumin as well as bovine serum fibrinogen adsorbs to a lesser extent as the hydrophilicity of the polymers increases. Platelet deposition and fibrin formation, examined using platelet-rich plasma, have been found to take place less significantly on PVA as well as sodium acrylate- and acrylamide-grafted polyethylene than on nongrafted and acrylic acid-grafted polyethylene. Ex vivo experiments with canine whole blood have shown that formation of thrombus on PVA is less than on siliconized glass but increases upon heat treatment which reduces the hydrophilicity. When PVA tubes of about 1 mm diameter are anastomosed to the carotid artery of rat, the patency rate is found to depend strongly on the anastomotic technique. From the results on the zeta potential and the experiments in vitro and ex vivo it can be concluded that the material having a surface from which solvated, neutral chains are extended into the outer aqueous phase may exhibit excellent resistance to thrombus formation.