A Case of Symptomatic Common Carotid Artery Occlusion Treated by a Bridging Bypass Using Short Saphenous Vein Graft.

An 86-year-old woman with initially asymptomatic severe right common carotid artery stenosis had frequent transient left hemiparesis 2 years after the initial diagnosis. Magnetic resonance angiography and three-dimensional computed tomography angiography demonstrated short-segment occlusion of the right carotid bifurcation with significant circumferential calcification, while magnetic resonance imaging demonstrated no ischemic lesions. No collateral blood flow through the anterior communicating artery and posterior communicating artery was observed. A bridging bypass from the distal common carotid artery to the proximal cervical internal carotid artery using a saphenous vein graft was made. There were no ischemic symptoms following the procedure. Bridging bypass using the short saphenous vein graft might be useful for short-segment common carotid artery occlusion.

The Hybrid Neurosurgeon: The Japanese Experience.

OBJECTIVE: In Japan, hybrid neurosurgeons who perform both open surgical clipping as well as endovascular embolization for the treatment of intracranial aneurysms are common. Although many Japanese neurosurgeons can perform surgical clipping of middle cerebral artery aneurysms or internal carotid artery-posterior communicating artery aneurysms and coil embolization of cerebral aneurysms using simple techniques-only a limited number of neurosurgeons are able to perform surgical clipping and endovascular procedures for anterior communicating artery aneurysms, paraclinoid, or posterior circulation aneurysms using both treatment modalities equally and safely. MATERIALS AND METHODS: The senior author's personal experience of more than 500 cases each of surgical clipping and endovascular embolization over the past 25 years included 110 cases of basilar tip aneurysms and 104 cases of paraclinoid internal carotid artery (ICA) aneurysms. RESULTS: The safety and efficacy of both treatments appears to be the same, while the durability of surgical clipping is superior to that of endovascular embolization. Among the 110 basilar tip aneurysms, 18 patients were treated by surgical clipping and 94 were treated by endovascular embolization. The initial results of endovascular therapy seemed to be better than those of surgical clipping, although the rate of retreatment was higher. Among the 104 cases of paraclinoid ICA aneurysm, 23 patients were treated by surgical clipping and 81 were treated by endovascular embolization. The results of both treatments seemed to be same, while surgical clipping had apparently good long-term durability. Over the past 15 years, the frequency of surgical clipping for basilar tip aneurysms has decreased, and the procedure may eventually be abandoned for this type of aneurysm. However, surgical clipping still offers several advantages in the treatment of paraclinoid aneurysms. CONCLUSIONS: Hybrid neurosurgeons can make reasonable decisions concerning the choice of treatment for cerebral aneurysms, as they perform both treatments and understand the benefits and drawbacks of each modality.

Attempt to delineate occluded arteries with initial plain computed tomography in acute cerebral arterial occlusion.

BACKGROUND: We used initial plain computed tomography to delineate acutely occluded internal carotid arteries or horizontal segments of middle cerebral arteries. If affected arteries could be delineated using initial plain computed tomography, useful information might be obtained that could support endovascular thrombectomies. METHODS: In 15 patients with occluded internal carotid arteries or horizontal segments of middle cerebral arteries, the affected middle cerebral artery was automatically traced using the extender function for blood vessel tracing with reference to the default value (window setting, 40; window width, 90) on Ziostation 2 (Ziosoft Inc., Tokyo, Japan) based on initial plain computed tomography data. RESULTS: The horizontal and sylvian segments of the middle cerebral artery were delineated in 15 and nine patients, respectively, based on plain computed tomography volume data. Images of occluded vessels delineated by plain computed tomography closely correlated with digital subtraction angiography. CONCLUSIONS: Initial plain computed tomography combined with a new generation workstation enabled the rapid delineation of occluded segments of intracranial vessels and could provide useful information that might improve the safety of endovascular thrombectomy.

[A Case of Trochlear Nerve Neurinoma Presenting with Pathological Laughter].

Trochlear nerve neurinomas are rare and solitary tumors without neurofibromatosis are extremely rare. We report a case of trochlear nerve neurinoma presenting with pathological laughter and diplopia. A 40-year-old male patient presented with diplopia and pathological laughter 2 months before admission. MRI showed a multicystic enhanced mass in the left tentorial incisura compressing the midbrain and the upper pons. The tumor was excised using the left trans-Sylvian approach with partial uncal resection. After excision of the tumor, the left trochlear nerve was identified on the surface of the lateral midbrain. The nerve was connected to the tumor. Pathological laughter completely resolved after the operation. This is the second reported case of trochlear nerve neurinoma presenting with pathological laughter. The lesion responsible for pathological laughter could be the midbrain, upper pons, diencephalon, or all of these.

STA-MCA Bypass Under Local Anesthesia.

BACKGROUND AND AIMS: The superficial temporal artery to middle cerebral artery (STA-MCA) bypass procedure has continually evolved and new strategies have been advocated to reduce anesthetic or surgical mortality and morbidity. Further simplifying and decreasing the invasiveness of STA-MCA bypass by performing this operation without endotracheal general anesthesia was deemed feasible in certain subsets of patients. METHODS: We performed STA-MCA bypass using local anesthesia using a sedative in 45 patients with hemodynamically compromised cerebrovascular occlusive disease as well as multiple comorbidities in the period between February 2010 and April 2016. The technique is based on preoperative identification of the point at which the donor and recipient vessels are in closest proximity. The preoperative use of computed tomography angiography allowed us to identify the target point precisely and use a minimally invasive procedure. All patients received dexmedetomidine as the sole sedative agent, together with scalp block local anesthesia with an unsecured airway. RESULTS: Successful STA-MCA bypass surgeries were achieved via a preselected minimally invasive approach in all cases. There was good hemodynamic stability throughout surgery. No airway/ventilation complications occurred and no patient was converted to general anesthesia. The patients subjectively tolerated this technique well with a high rate of satisfaction. Postoperative magnetic resonance angiography confirmed patent bypass in 44 of 45 patients (patency rate of 97.8%). There were two postoperative hyper-perfusion syndromes and one cerebral ischemia with transient neurological symptoms (postoperative complication rate of 6.3%). No recurrence of ipsilateral cerebral ischemia was observed during the follow-up periods. There was one contralateral cardiogenic cerebral embolism during the follow-up period. The overall stroke rate was calculated as 1%/patient/year. CONCLUSIONS: Our initial experience confirms the feasibility of performing STA-MCA bypass under local anesthesia without endotracheal general anesthesia.

In-stent hypodense area at two weeks following carotid artery stenting predicts neointimal hyperplasia after two years.

Introduction It has not been reported how long the follow-up study after carotid artery stenting (CAS) should be continued. The purpose of the present study is to clarify the dynamic change of the in-stent neointimal layer and residual arterial lumen by two years following CAS using three-dimensional computed tomography angiography (3D CTA) with volume rendering. Methods Thirty-six stented carotid arteries in 34 consecutive patients were examined by 3D CTA with volume rendering at two weeks and 3, 6, 12, 24 months of follow-up. Results An in-stent hypodense area could be detected in 10 of 36 (27.8%) carotid arteries at two weeks after CAS. In-stent hypodense areas gradually declined thereafter by three months. In the course of longer follow-up, the layer of the in-stent hypodense area (neointimal hyperplasia) continued to grow in size for up to 24 months. Patients with an in-stent hypodense area at two weeks have a thicker layer of neointimal hyperplasia at 24 months than patients without in-stent hypodense area at two weeks' follow-up. The predictive factors for growing neointimal hyperplasia at 24 months in multiple regression analysis are ulcer formation in pretreatment stenosis and the thickness of in-stent hypodense area at two weeks following CAS. Conclusion Our results suggest that follow-up study should be continued for a longer period even if in-stent restenosis could not be detected at one year following CAS. Especially in cases with ulcer formation in pretreatment stenosis and with a subacute in-stent hypodense area after CAS, longer follow-up is strongly recommended.

Diabetes mellitus and carotid artery plaques exhibiting high-intensity signals on MR angiography are related to increased platelet reactivity after carotid artery stenting.

BACKGROUND: Increased platelet reactivity after carotid artery stenting (CAS) may cause thromboembolic complications. OBJECTIVE: This study aimed to investigate the incidence of increased platelet reactivity after CAS and to determine the factors related to it. METHODS: Patients who underwent CAS were recruited prospectively. They received pre-procedural antiplatelet therapy comprising some combination of aspirin (100 mg/day), clopidogrel (75 mg/day), and/or cilostazol (200 mg/day) for a minimum of 7 days. ADP- and collagen-induced platelet aggregation were measured before and 4 days after CAS. Changes in platelet reactivity were reported as changes in the categorized platelet reactivity grade based on the effective dose 50%. Clinical characteristics of patients with and without increased platelet reactivity were compared. RESULTS: Among 38 consecutive patients who underwent CAS, 18 (47%) exhibited increased platelet reactivity. Diabetes mellitus (OR 15.0; 95% CI 2.1 to 106.5; p=0.007) and carotid artery plaques exhibiting high-intensity signals (HIS) on time-of-flight MR angiography (TOF-MRA) (OR 25.2; 95% CI 2.0 to 316.2; p=0.013) were independently associated with increased platelet reactivity in a multivariate analysis. CONCLUSIONS: Increased platelet reactivity occurred in nearly half of the studied patients subjected to CAS and was independently associated with diabetes mellitus and carotid artery plaques exhibiting HIS on TOF-MRA.

Surgical Treatment of Complex Cerebral Aneurysms Using Interposition Short Vein Graft.

BACKGROUND AND AIMS: Cerebral revascularization strategies may become necessary in select patients who present with challenging cerebral aneurysms. In this study, we present the techniques of a moderate-flow extra-intracranial bypass using a short interposition vein graft and concurrent aneurysm management. METHODS: The short interposition vein graft was used for the reconstruction of complex cerebral aneurysms in nine patients. In eight of them, the superficial temporal artery (STA) main trunk was used as a donor site for the anastomosis of a short interposition vein graft, and an extracranial vertebral artery (VA) was used in one case. The vein grafts were implanted into the M2 of the middle cerebral artery (MCA) for the adjunctive treatment of internal carotid artery (ICA) aneurysms in three patients, into the A3 of the anterior cerebral artery (ACA) in one patient, into the P2 of the posterior cerebral artery (PCA) for the adjunctive treatment of complex PCA aneurysms in three patients, into the P3 of the PCA for the adjunctive treatment of a basilar artery (BA) trunk giant aneurysm in 1 patient, and into the postero-inferior cerebellar artery (PICA) for the adjunctive treatment of the VA dissecting aneurysm in one patient. RESULTS: All of the bypasses were patent. Intraoperative flow measurements confirmed a moderate flow-carrying capacity of the short interposition short vein graft (30-70 ml; mean: 43 ml/min). CONCLUSION: The STA main trunk to proximal MCA/PCA bypass and the extracranial VA to PICA bypass using short interposition vein grafts can provide sufficient blood flow and may be a reasonable alternative to the conventional EC-IC bypass/high-flow bypass.

Surgical Approach to Ponto-mesencephalic Cavernoma.

BACKGROUND AND AIMS: The surgical treatment of intrinsic brainstem lesions remains a major challenge. In this article we present the results of using an infratentorial-supracerebellar (ITSC) approach for the resection of intrinsic ponto-mesencephalic lesions. MATERIALS AND METHODS: The authors reviewed the cases of 16 patients. In seven of them, a paramedian ITSC transcollicular approach was used to resect intrinsic mid-brain lesions, and in the other nine patients, an intermediate or lateral ITSC infra-trochlear approach was used for ponto-mesencephalic lesions. RESULTS: All 16 lesions were completely removed. There was no recurrence of bleeding during the follow-up period, and no mortality. In seven patients with mid-brain lesions, the preoperative ocular symptoms improved in three of them, and the neurological deficits - other than ocular symptoms improved - in five of them. The preoperative modified Rankin Scale score of 1.8 improved to 1.3 postoperatively. In nine patients with a ponto-mesencephalic lesion, the preoperative ocular symptoms improved in four of nine patients, and the neurological deficits other than ocular symptoms improved in five of them, while one patient exhibited venous infarction in a cerebellar hemisphere that caused neurological deterioration. The preoperative modified Rankin Scale score of 3.75 improved to 2.5 postoperatively in these patients. CONCLUSION: The ITSC transcollicular or infra-trochlear approach provide a wide operative entry zone and minimize the functional damage to the surrounding structures for access to ponto-mesencephalic lesions.

STA-MCA/STA-PCA Bypass Using Short Interposition Vein Graft.

BACKGROUND AND AIMS: Superficial temporal artery (STA) is the mainstay of donor vessels for extra-intracranial bypass (EC-IC bypass) in cerebral revascularization. However, the typically used STA frontal or parietal branch is not always adequate in its flow-carrying capacity. In the present study, we provide an update on an alternative strategy: the use of the STA main trunk as a donor vessel, with a short vein interposition graft. METHODS: Seven patients in whom the STA main trunk was used as a donor site for anastomosis of a short interposition vein graft were included. The grafts were implanted into the M2 of the middle cerebral artery for adjunctive treatment of IC anterior wall blood-blister aneurysms in two patients, for revascularization of an internal carotid artery occlusion in one patient, into the P2/3 of the posterior cerebral artery (PCA) for adjunct treatment of complex PCA aneurysms in three patients and into the P3 of PCA for adjunct treatment of basilar artery (BA) trunk giant aneurysm in one patient. RESULTS: All the bypasses were patent. Intraoperative flow measurements confirmed a moderate flow-carrying capacity of the STA main trunk-interposition short vein graft (20-50 ml; mean 43 ml/min). CONCLUSION: The STA main trunk has a larger diameter than the distal branch; therefore, it would be expected to have a significantly higher flow capacity than its branches. STA main trunk to proximal MCA/PCA bypass using short interposition vein grafts can provide sufficient blood flow, and may be a reasonable alternative to ECA to MCA/PCA bypass using long vein grafts.

Superficial temporal artery-middle cerebral artery bypass using local anesthesia and a sedative without endotracheal general anesthesia.

OBJECT: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses have continually evolved, and new strategies have been advocated for reducing anesthetic or surgical morbidity and mortality. Further simplifying, and decreasing the invasiveness of, STA-MCA bypass by performing this operation without endotracheal general anesthesia was believed to be feasible in certain subsets of patients. METHODS: The authors performed STA-MCA bypass using local anesthesia with a sedative in 10 patients with hemodynamically compromised occlusive cerebrovascular disease, as well as multiple comorbidities, between February 2010 and September 2011. The technique is based on the preoperative identification of the point at which the donor and recipient vessels are in closest proximity. Preoperative use of CT angiography allowed the authors to identify the target point precisely and use a minimally invasive procedure. All patients received dexmedetomidine as the sole sedative agent, together with scalp-blocking local anesthesia, with an unsecured airway. RESULTS: Successful STA-MCA bypass surgeries were achieved via a preselected minimally invasive approach in all cases. There was good hemodynamic stability throughout surgery. No airway or ventilation complications occurred, and no patients were converted to general anesthesia. Subjectively, patients tolerated the technique well with a high rate of satisfaction. There were no perioperative morbidities or deaths. Postoperative MR angiography confirmed a patent bypass in all patients. All patients remained symptom free and returned to normal daily life following the operation. CONCLUSIONS: This initial experience confirms the feasibility of performing STA-MCA bypass without endotracheal general anesthesia. This novel technique produced a high degree of patient satisfaction.

Microneurosurgical management of anterior choroid artery aneurysms.

OBJECTIVE: Anterior choroid artery aneurysms (AChAAs) constitute 2%-5% of all intracranial aneurysms. They are usually small, thin walled with one or several arteries originating at their base, and often associated with multiple aneurysms. In this article, we review the practical microsurgical anatomy, the preoperative imaging, surgical planning, and the microneurosurgical steps in the dissection and the clipping of AChAAs. METHODS: This review, and the whole series on intracranial aneurysms (IAs), are mainly based on the personal microneurosurgical experience of the senior author (J.H.) in two Finnish centers (Helsinki and Kuopio) that serve, without patient selection, the catchment area in Southern and Eastern Finland. RESULTS: These two centers have treated more than 10,000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 IAs, 831 patients (28%) had altogether 980 internal carotid artery (ICA) aneurysms, of whom 95 patients had 99 (2%) AChAAs. Ruptured AChAAs, found in 39 patients (41%), with median size of 6 mm (range = 2-19 mm), were associated with intracerebral hematoma (ICH) in only 1 (3%) patient. Multiple aneurysms were seen in 58 (61%) patients. CONCLUSIONS: The main difficulty in microneurosurgical management of AChAAs is to preserve flow in the anterior choroid artery originating at the base and often attached to the aneurysm dome. This necessitates perfect surgical strategy based on preoperative knowledge of 3 dimensional angioarchitecture and proper orientation during the microsurgical dissection.

Pure vasogenic edema caused by cerebral hyperperfusion after superficial temporal artery to middle cerebral artery anastomosis--case report.

A 63-year-old patient presented with cerebral hyperperfusion manifesting as transient aphasia and general tonic convulsions 3 and 4 days after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. Diffusion-weighted magnetic resonance (MR) imaging revealed a focal low-intensity area at the site of anastomosis in the left temporal lobe, with high apparent diffusion coefficient, together with focal intense increase in cerebral blood flow in the same region. This lesion was considered to be pure vasogenic edema caused by cerebral hyperperfusion. Additional treatment with intravenous drip infusion of free radical scavenger and reduction in blood pressure with nicardipine improved the patient's symptoms and brain edema. The brain edema gradually decreased on MR imaging and completely disappeared at 3 months after bypass surgery. Cerebral hyperperfusion is often encountered after recanalization of occlusive arteries, removal of arteriovenous malformations, and carotid endarterectomy, but may also occur after STA-MCA anastomosis.

Treatment of ruptured cerebral aneurysms - clip and coil, not clip versus coil.

BACKGROUND AND AIMS: Recent advances in neurosurgery and interventional neuroradiology have brought us a new aspect in the treatment of cerebral aneurysms. The present single-surgeon series provides a balanced overview of the treatment of ruptured aneurysms in surgical clipping and coil embolization. CLINICAL MATERIALS AND METHODS: One hundred consecutive patients with ruptured cerebral aneurysms underwent surgical clipping or endovascular coil embolization between January 2005 and December 2007. All patients underwent clipping or coil embolization of at least one ruptured cerebral aneurysm by a single neurosurgeon (YK) who performed both the surgical clipping and endovascular coiling. RESULTS: Of the 48 surgically treated patients, 37 (77.1%) achieved a favorable outcome. Of the 52 patients who underwent endovascular embolization, 37 (71.2%) achieved a favorable outcome. No significant difference was observed regarding the proportion of favorable outcomes between the two treatment modalities. Five patients (9.6%) who underwent endovascular embolization needed re-treatments, while no re-treatment was necessary in the surgically treated patients. The rates of symptomatic vasospasm and shunt dependent hydrocephalus were 18.8% and 14.6%, respectively, in the clipped patients, and 19.2% and 21.2%, respectively, in the coiled patients. Endovascular coiling of ruptured aneurysms has a tendency towards a higher risk of developing shunt dependent hydrocephalus. CONCLUSION: A combined microsurgical-endovascular approach can achieve the best outcomes for patients with ruptured cerebral aneurysms. Our findings support the policy of "Clip and Coil, not Clip versus Coil."

Microneurosurgical management of internal carotid artery bifurcation aneurysms.

BACKGROUND: Internal carotid artery bifurcation aneurysms form 2% to 9% of all IAs. They are more frequent in younger patients than other IAs. In this article, we review the practical microsurgical anatomy, the preoperative imaging, surgical planning, and the microneurosurgical steps in the dissection and the clipping of ICAbifAs. METHODS: This review and the whole series on IAs are mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland. RESULTS: These 2 centers have treated more than 11 000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 IAs, 831 (28%) patients had altogether 980 ICA aneurysms, of whom 137 patients had 149 (4%) ICAbifAs. Ruptured ICAbifAs, found in 78 (52%) patients, with median size of 8 mm (range, 2-60 mm), were associated with ICH in 15 (19%) patients. Ten (7%) ICAbifAs were giant (> or = 25 mm). Multiple aneurysms were seen in 59 (43%) patients. The ICAbifAs represented 18% of all IAs ruptured before the age of 30 years. CONCLUSIONS: The main difficulty in microneurosurgical management of ICAbifAs is to preserve flow in all the perforators surrounding or adherent to the aneurysm dome. This necessitates perfect surgical strategy based on preoperative knowledge of 3D angioarchitecture and proper orientation during the microsurgical dissection.

Follow-up study on in-stent thrombosis after carotid stenting using multidetector CT angiography.

INTRODUCTION: The purpose of the present study was to evaluate the role of multidetector three-dimensional computed tomography angiography (3D CTA) for evaluating both the residual arterial lumen and the sequential change in the intraluminal diameter and thrombus formation following carotid artery stenting (CAS). MATERIALS AND METHODS: Twenty consecutive patients consisting of 23 successfully stented carotid arteries were examined by 3D CTA with volume-rendering at 2, 4, 8, 12 weeks and 6, 12 months of follow-up. RESULTS: The eccentric in-stent hypodense area could be detected in ten of 23 (43.5%) carotid arteries at 2 weeks of follow-up, and they then gradually declined until they almost disappeared at 12 weeks. Eccentric in-stent hypodense areas in the acute and subacute phase (up to 12 weeks after CAS) were found in nine out of 16 carotid arteries with longer stents (3 or 4 cm in size) deployed across the carotid bifurcation, whereas no eccentric in-stent hypodense area could be observed in the patients with a short stent (2 cm) deployed only to the internal carotid artery. Seven of the ten observed eccentric hypodense areas presented on the dorsal surface at the carotid bifurcation level. CONCLUSION: Carotid 3D CTA for evaluating residual lumen and in-stent thrombus formation after CAS is considered to be a useful diagnostic method. To avoid stent occlusion, both the acute and subacute phases following CAS (up to 12 weeks) call for the administration of appropriate anti-platelet therapy and careful observations of the patients.

Cerebral aneurysms: conventional microsurgical technique and endovascular method.

Recent advances in neurosurgery and interventional neuroradiology have brought us a new aspect in the treatment of cerebral aneurysms. The present series provides a balanced overview of the treatment of aneurysms in surgical clipping and coil embolization. Between January 2004 and March 2006, a total of 119 consecutive patients with cerebral aneurysms underwent endovascular embolization or surgical clipping. Of these, 79 patients suffered an aneurysmal subarachnoid hemorrhage (SAH), whereas the remaining 40 patients had nonruptured cerebral aneurysms. Of the 32 surgically treated patients, 25 (78.1%) achieved a favorable outcome. Of the 47 patients who underwent endovascular embolization, 38 (80.9%) achieved a favorable outcome. No significant difference was observed regarding the proportion of favorable outcomes between the two treatment modalities. Four patients (5.5%) who underwent endovascular embolization required re-treatments but no re-treatments were needed in the surgically treated patients. Of the 40 cases with nonruptured aneurysms, 12 (30%) were treated using surgical clipping, whereas 28 (70%) underwent endovascular embolization. The complication rates of the two treatment modalities demonstrated no significant difference. A combined microsurgical-endovascular team approach is thus considered to provide the most effective means to achieve favorable outcomes for patients with cerebral aneurysms. A case-by-case evaluation based on the individual characteristics of each aneurysm is therefore considered to be essential.

Culture method for the induction of neurospheres from mouse embryonic stem cells by coculture with PA6 stromal cells.

Embryonic stem (ES) cells proliferate and maintain their pluripotency for over 1 year in vitro and may therefore provide a sufficient source for cell therapies. However, most of the previously reported methods for obtaining a source for cell therapies have not been simple. We describe here a novel method for induction of neurospheres from mouse ES cells by coculturing on PA6 cells instead of the formation of embryoid bodies. The ES cells cocultured with the PA6 stromal cell line for at least 3 days were capable of differentiating into spheres. The cells in the spheres were all green fluorescent protein (GFP) positive, showing that they were derived from GFP-expressing D3-ES cells. The spheres contained nestin-positive cells. The number of spheres increased when they were cocultured with PA6 for a longer period. Sphere formation was observed even after 10 mechanical dissociations and subculturings, showing its self-renewal ability. The cells differentiated into microtubule-associated protein-2 (MAP2)-positive neuronal cells and glial fibrillary acidic protein (GFAP)-positive glial cells. gamma-Aminobutyric acid-positive cells and tyrosine hydroxylase-positive cells were also observed in the spheres. The percentages of the MAP2- or GFAP-positive cells in the sphere changed according to the period of coculture on PA6 cells. At an early stage of coculture, more neurons were generated and, at a later period, more glial cells were generated. These results suggested that neurosphere could be generated from ES cells by coculturing with PA6, and that these cells resembled neural stem cells derived from mouse fetal brain tissue.

Factors predictive of cerebral hyperperfusion after carotid angioplasty and stent placement.

BACKGROUND AND PURPOSE: Cerebral hyperperfusion syndrome has been increasingly reported as a complication of carotid angioplasty and stent placement. The aim of the present study was to determine significant predictors of hyperperfusion phenomenon after carotid angioplasty and stent placement. METHODS: We retrospectively reviewed 30 consecutive patients with unilateral severe carotid stenosis who underwent angioplasty and stent placement. Resting cerebral blood flow (CBF) and cerebral vasoreactivity (CVR) to acetazolamide challenge were quantitatively measured to evaluate cerebral hemodynamic reserve. Split-dose [(123)I] iodoamphetamine single photon emission CT (SPECT) was performed before and 7 days after carotid angioplasty and stent placement. Technetium-99m hexamethylpropyleneamine oxime (HMPAO) SPECT was performed immediately after the procedure. RESULTS: Three patients had cerebral hyperperfusion phenomenon immediately after angioplasty and stent placement, as shown by HMPAO SPECT: One developed status epilepticus 2 weeks after the procedure. Significant predictors of hyperperfusion included patient age, pretreatment CVR, and pretreatment asymmetry index ([ipsilateral resting CBF/contralateral resting CBF] x 100). Variables determined not to be significant risk factors included pretreatment resting CBF value, degree of carotid stenosis, and interval from the onset of ischemic symptoms. CONCLUSION: Significant predictors of hyperperfusion phenomenon after carotid angioplasty and stent placement included patient age, pretreatment CVR, and pretreatment asymmetry index. Pretreatment CBF measurements, including those obtained by quantifying CVR and performing SPECT immediately after the procedure may aid in identifying patients at risk and in initiating careful monitoring and control of blood pressure to prevent hyperperfusion syndrome.

Hepatocyte growth factor promotes neuronal differentiation of neural stem cells derived from embryonic stem cells.

We previously reported that hepatocyte growth factor (HGF) promoted proliferation of neurospheres and neuronal differentiation of neural stem cells (NSCs) derived from mouse embryonic brain. In this study, spheres from mouse embryonic stem (ES) cells were generated by floating culture following co-culture on PA6 stromal cells. In contrast to the behavior of the neurospheres derived from embryonic brain, addition of HGF to the growth medium of the floating cultures decreased the number of spheres derived from ES cells. When spheres were stained using a MAP-2 antibody, more MAP-2-positive cells were observed in spheres cultured with HGF. When HGF was added to the growth and/or differentiation medium, more MAP-2-positive cells were also obtained. These results suggest that HGF promotes neuronal differentiation of NSCs derived from ES cells.