Intracranial chondrosarcoma located in the region of the posterior clinoid process: a case report.

Intracranial chondrosarcomas located in the region of the posterior clinoid process have not been focused on. Here, we report the case of a 29-year-old woman with a skull base tumor in that region. Seven years after the diagnosis, the tumor had grown and showed calcification and tumor stain; chondrosarcoma, posterior clinoid meningioma, and chordoma were suspected. The patient underwent subtotal tumor resection, and the histopathological study revealed that the tumor was a low-grade chondrosarcoma. Chondrosarcomas can be located in the region of the posterior clinoid process, and not only chordomas but also posterior clinoid meningiomas should be considered as a differential diagnosis of tumors located in that region, especially when the tumor has calcification or receives a vascular supply.

Pineal region pilocytic astrocytoma showing uncommon growth: a case report.

Pineal region pilocytic astrocytomas are extremely rare, and there is limited information about their radiological features. We report the case of a 22-year-old woman with a cystic lesion in the pineal region. In the 2 years after diagnosis, the lesion irregularly extended along the bilateral internal cerebral veins and the inferolateral surface of the corpus callosum. Gross total resection was achieved, and the histopathological study revealed that the lesion was a pilocytic astrocytoma. The lesion exhibited uncommon growth, leading to difficulty in establishing an accurate preoperative diagnosis. It should be noted that pineal region pilocytic astrocytomas can demonstrate atypical appearances.

Insulin degludec/insulin aspart in Japanese patients with type 1 diabetes mellitus: Distinct prandial and basal glucose-lowering effects.

AIMS/INTRODUCTION: Insulin degludec/insulin aspart (IDegAsp) is a soluble co-formulation of long-acting insulin degludec (IDeg) and rapid-acting insulin aspart (IAsp). The present study investigated the pharmacodynamic properties of IDegAsp in Japanese patients with type 1 diabetes mellitus. MATERIALS AND METHODS: In this randomized, double-blind, two-period, cross-over trial, 21 Japanese patients with type 1 diabetes mellitus received single doses of 0.5 U/kg IDegAsp and biphasic insulin aspart 30 in a randomized sequence (13-21 days washout between treatments). The pharmacodynamic response was evaluated in a 26-h euglycemic glucose clamp (target 5.5 mmol/L). Single-dose IDegAsp glucose infusion rate (GIR) profiles were extrapolated to steady state using modeling. RESULTS: The IDegAsp single-dose GIR profile showed a clear distinction between the effects of the bolus (IAsp) and basal (IDeg) components in IDegAsp. When simulated to steady state, the GIR profile of IDegAsp was shifted upwards compared with the single-dose profile, and showed a rapid onset of action and a distinct peak from the IAsp component followed by a separate and sustained basal action from the long-acting IDeg component. For biphasic insulin aspart 30, the initial shape of the GIR profile was similar to IDegAsp, but GIR continuously decreased from maximum and reached zero 18-20 h post-dosing. The characteristics of the GIR profile for IDegAsp were retained when simulated to steady state in a twice-daily dosing regimen. DISCUSSION: In Japanese patients with type 1 diabetes mellitus, the pharmacodynamic profile of IDegAsp is characterized by distinct prandial and basal effects from the IAsp and IDeg components, consistent with what has been reported previously in Caucasian patients with type 1 diabetes mellitus.

Upregulation of tissue inhibitor of metalloproteinase-1 contributes to restoration of the extracellular matrix in the rabbit basilar artery during cerebral vasospasm after subarachnoid hemorrhage.

Vascular remodeling caused by extracellular matrix (ECM) metabolism contributes to the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). The balance between tissue inhibitor of metalloproteinases (TIMPs) and matrix metalloproteinases (MMPs) plays an important role in ECM remodeling. We investigated the mechanism of vascular remodeling following cerebral vasospasm in a rabbit double hemorrhage model. Rabbit basilar arteries were harvested on days 3, 5, and 7 after initial hemorrhage. TIMP-1, TIMP-2, MMP-2, and MMP-9 mRNA and protein expression were investigated with microarray analysis, quantitative real-time PCR, immunoblot analysis, and enzyme-linked immunosorbent assay (ELISA). The expression and localization of TIMP-1, TIMP-2, MMP-2, MMP-9, elastin, fibronectin, laminin, and collagens I, III, and IV were investigated with immuohistochemical staining. After SAH, TIMP-1 mRNA and protein expression were significantly increased on day 3 and then decreased to the control level on days 5 and 7. MMP-9 protein expression was significantly increased on day 7. TIMP-2 and MMP-2 mRNA and protein expression were significantly increased on day 7. Elastin, fibronectin, laminin, and collagens I, III, and IV protein expression was decreased on day 3 and then restored to control levels on day 7. Upregulation of TIMP-1 during the early phase of cerebral vasospasm may contribute to the recovery of the ECM during the late phase of cerebral vasospasm, resulting in a protective role of TIMP-1 from cerebral vasospasm. Moreover, the increase in arterial compliance by the decrease in ECM during the early phase of cerebral vasospasm may facilitate vasoconstriction of the cerebral artery.

[Clinical and histological characteristics of ictal onset zone in cases of intractable epilepsy associated with dysembryoplastic neuroepithelial tumor].

Although the epileptogenic location of dysembryoplastic neuroepithelial tumors (DNTs) is controversial, it has recently been thought to be located within cortical dysplasia (CD) due to its frequent association with CD. Among the 84 resection surgeries for intractable epilepsy performed in our institution between January 2003 and April 2010, three patients had epileptogenic DNTs. In two cases, chronic subdural electrocorticography (ECoG) was performed, and the ictal onset zone was revealed to be in the cortex around the DNT. The ictal onset zone was resected along with the DNT, and good seizure outcome was achieved. Although histological examination of the ictal onset zone revealed mild gliosis, coexistence of CD was not noted. In the third case, the DNT was located in the left lateral temporal lobe and the intraoperative ECoG revealed frequent paroxysmal activity in the medial temporal lobe. Resection of the lateral temporal lobe involving the tumor did not result in good seizure control. The optimal surgical treatment of DNT is controversial. Some authors consider lesionectomy to be sufficient for good seizure control, whereas others advocate that additional resection of the epileptogenic zone beside the tumor improves outcome. Because the epileptogenic location of DNT varies among cases, it is important to identify its location by preoperative multimodal examinations, including chronic subdural ECoG recordings.

Mechanisms underlying increased vascular smooth muscle contractility in the rabbit basilar artery following subarachnoid hemorrhage.

Increased vascular contractility plays an important role in the development of cerebral vasospasm following subarachnoid hemorrhage (SAH). Here, we summarize our current knowledge regarding molecular mechanisms that contribute to increased smooth muscle contractility of rabbit basilar artery following SAH. Our studies demonstrated that upregulation of receptor expression, impairment of feedback regulation of receptor activity, and enhancement of myofilament Ca²âº sensitization might lead to increased smooth muscle contractility following SAH.

The single and double blood injection rabbit subarachnoid hemorrhage model.

Over the past 30 years, the rabbit subarachnoid hemorrhage model (SAH) has been used for investigating the post-hemorrhage pathology, especially with respect to understanding of the mechanisms of cerebral vasospasm. However, the molecular mechanisms of cerebral vasospasm remain to be elucidated. Furthermore, it is not clear whether the rabbit SAH model is suitable for the investigation of pathological conditions other than cerebral vasospasm, such as early brain injury. Therefore, the properties of the rabbit SAH model need to be validated, and the reasons for using the rabbit should be clarified. This review explores the settings and technical issues of establishing a rabbit cisterna magna single and double blood injection SAH model and discusses the characteristics and feasibilities of the models.

Upregulation of relaxin after experimental subarachnoid hemorrhage in rabbits.

BACKGROUND: Although relaxin causes vasodilatation in systemic arteries, little is known about its role in cerebral arteries. We investigated the expression and role of relaxin in basilar arteries after subarachnoid hemorrhage (SAH) in rabbits. METHODS: Microarray analysis with rabbit basilar artery RNA was performed. Messenger RNA expression of relaxin-1 and relaxin/insulin-like family peptide receptor 1 (RXFP1) was investigated with quantitative RT-PCR. RXFP1 expression in the basilar artery was investigated with immunohistochemistry. Relaxin concentrations in cerebrospinal fluid (CSF) and serum were investigated with an enzyme-linked immunosorbent assay. Using human brain vascular smooth muscle cells (HBVSMC) preincubated with relaxin, myosin light chain phosphorylation (MLC) was investigated with immunoblotting after endothelin-1 stimulation. RESULTS: After SAH, RXFP1 mRNA and protein were significantly downregulated on day 3, whereas relaxin-1 mRNA was significantly upregulated on day 7. The relaxin concentration in CSF was significantly elevated on days 5 and 7. Pretreatment with relaxin reduced sustained MLC phosphorylation induced by endothelin-1 in HBVSMC. CONCLUSION: Upregulation of relaxin and downregulation of RXFP1 after SAH may participate in development of cerebral vasospasm. Downregulation of RXFP1 may induce a functional decrease in relaxin activity during vasospasm. Understanding the role of relaxin may provide further insight into the mechanisms of cerebral vasospasm.

Intraoperative visualization of cerebral oxygenation using hyperspectral image data: a two-dimensional mapping method.

PURPOSE: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is an important technique for cerebrovascular reconstruction. Intraoperative hemodynamic imaging is needed to perform cerebrovascular reconstruction safely and effectively. Optical intrinsic signal (OIS) imaging is commonly used for assessing cerebral hemodynamics in experimental studies, because it can provide high-resolution mapping images. However, OIS is not used clinically due to algorithm, instrumentation and spectral resolution limitations. We tested the feasibility of a hyperspectral camera (HSC) for assessment of cortical hemodynamics with spectral imaging of the cerebral cortex in rats and in vivo humans. METHODS: A hyperspectral camera (HSC) was tested in a rat model of cerebral ischemia (middle cerebral artery occlusion) and during human revascularization surgery (STA-MCA anastomosis). Changes in cortical oxygen saturation were derived from spectral imaging data (400-800 nm) collected by exposing the cortex to Xenon light. Reflected light was sampled using the HSC. The system was then tested intraoperatively during superficial temporal artery to middle cerebral artery anastomosis procedures. Comparison with single-photon emission computed tomography (SPECT) imaging data was done. RESULTS: During middle cerebral artery occlusion in rats, the HSC technique showed a significant decrease in cortical oxygen saturation in the ischemic hemisphere. In clinical cases, the cortical oxygen saturation was increased after STA-MCA anastomosis, which agreed with the SPECT imaging data. CONCLUSION: Continuous collection of imaging spectroscopic data is feasible and may provide reliable quantification of the hemodynamic responses in the brain. The HSC system may be useful for monitoring intraoperative changes in cortical surface hemodynamics during revascularization procedures in humans.

Executive function and diffusion in frontal white matter of adults with moyamoya disease.

BACKGROUND: Cognitive impairment is a frequent complication of moyamoya disease (MMD) in adults. Chronic hypoperfusion in frontal lobes can lead to subtle brain injury, resulting in cognitive dysfunctions. Apparent diffusion coefficient (ADC) in normal-appearing white matter on conventional magnetic resonance imaging correlates with cerebral hemodynamics in the frontal lobe. OBJECTIVE: The purpose of this study was to examine the relationship of ADC with executive function in patients with MMD. METHODS: Thirty-one patients (25 women and 6 men; mean age, 32.6 ± 10.4 years) were included in this study. Executive function was evaluated by the Frontal Assessment Battery (FAB) at 21.5 ± 7.5 years after disease onset. ADC was measured in the normal-appearing frontal white matter. RESULTS: ADC was statistically related to the occurrence of executive dysfunction in multivariate analysis (P = .0179). Total FAB score and ADC were negatively correlated (r(2) = .22; P = .0072; Spearman correlation coefficient, -.41; P = .024). Elevated ADC predicted executive dysfunction (area under the receiver operating characteristic curve, .73; 95% confidence interval, .55-.91; P = .029). CONCLUSIONS: The association of ADC with executive function might suggest that ADC is useful in screening for executive dysfunction during follow-up in the outpatient setting.

Altered expression of diabetes-related genes in Alzheimer's disease brains: the Hisayama study.

Diabetes mellitus (DM) is considered to be a risk factor for dementia including Alzheimer's disease (AD). However, the molecular mechanism underlying this risk is not well understood. We examined gene expression profiles in postmortem human brains donated for the Hisayama study. Three-way analysis of variance of microarray data from frontal cortex, temporal cortex, and hippocampus was performed with the presence/absence of AD and vascular dementia, and sex, as factors. Comparative analyses of expression changes in the brains of AD patients and a mouse model of AD were also performed. Relevant changes in gene expression identified by microarray analysis were validated by quantitative real-time reverse-transcription polymerase chain reaction and western blotting. The hippocampi of AD brains showed the most significant alteration in gene expression profile. Genes involved in noninsulin-dependent DM and obesity were significantly altered in both AD brains and the AD mouse model, as were genes related to psychiatric disorders and AD. The alterations in the expression profiles of DM-related genes in AD brains were independent of peripheral DM-related abnormalities. These results indicate that altered expression of genes related to DM in AD brains is a result of AD pathology, which may thereby be exacerbated by peripheral insulin resistance or DM.

Preoperative evaluation and surgical strategies for craniocervical junction dural arteriovenous fistula with multiple feeders: case report and review of the literature.

Craniocervical junction dural arteriovenous fistula (CCJDAVF) fed by bilateral vertebral arteries (VAs) is extremely rare. We report a case of a 63-year-old man presenting with progressive myelopathy caused by a CCJDAVF, which was fed by bilateral VAs and occipital and ascending pharyngeal arteries with multiple shunting points and that drained into intracranial sinus and spinal veins. The dural arteriovenous fistula (DAVF) was successfully treated surgically using stepwise indocyanine green (ICG) videoangiography. After surgery, the DAVF disappeared and myelopathy was markedly improved. We show detailed preoperative images and intraoperative findings of this rare DAVF and emphasize the importance of selective angiography for preoperative evaluation of feeding arteries and the usefulness of intraoperative ICG videoangiography for both identification of the fistula and confirmation of its obliteration.

Long-term hearing outcome after retrosigmoid removal of vestibular schwannoma.

Although many investigators have reported the hearing function in the immediate postoperative period in patients with vestibular schwannoma (VS), little is known about the long-term outcomes of the postoperative hearing. The aim of this study was to analyze the long-term hearing outcomes at a mean follow-up of 5 years in patients with unilateral VS treated via the retrosigmoid approach. Twenty-four patients with immediate postoperative serviceable hearing who underwent repeated audiogram or phone interview were included in this study. During the mean follow-up period (68.8 ± 30.2 months, range 14-123 months), serviceable hearing was preserved in 20 out of the 24 patients (83%). Pure tone average (PTA) was reevaluated within 6 months in seven patients. In the two patients whose PTA deteriorated ≥ 5 dB in 6 months after surgery, their PTA worsened ≥ 15 dB compared to the immediate postoperative PTA. In the remaining five patients whose PTA deteriorated < 5 dB in 6 months after surgery, PTA was maintained within a 15-dB deterioration at the final follow-up (p = 0.04, Fisher's exact test). According to Kaplan-Meier survival plots, the 5-year or 7-year preservation rate of serviceable hearing was 86.2% or 71.8%, respectively. Further study will be needed to clarify the mechanism underlying the long-term decline of serviceable hearing; however, the deterioration of PTA in the early postoperative period may help to predict the long-term outcomes of hearing.

Three-dimensional high-definition neuroendoscopic surgery: a controlled comparative laboratory study with two-dimensional endoscopy and clinical application.

BACKGROUND: The purpose of this research was to investigate the usefulness of three-dimensional (3D) endoscopy compared with two-dimensional (2D) endoscopy in neuroendoscopic surgeries in a comparative study and to test the clinical applications. METHODS: Forty-three examinees were divided into three groups according to their endoscopic experience: novice, beginner, or expert. Examinees performed three separate tasks using 3D and 2D endoscopy. A recently developed 3D high-definition (HD) neuroendoscope, 4.7 mm in diameter (Shinko Optical Co., Ltd., Tokyo, Japan) was used. In one of the three tasks, we developed a full-sized skull model of acrylic-based plastic using a 3D printer and a patient's thin slice computed tomography data, and evaluated the execution time and total path length of the tip of the pointer using an optical tracking system. Sixteen patients underwent endoscopic transnasal transsphenoidal pituitary surgery using both 3D and 2D endoscopy. RESULTS: Horizontal motion was evaluated using task 1, and anteroposterior motion was evaluated with task 3. Execution time and total path length in task 3 using the 3D system in both novice and beginner groups were significantly shorter than with the 2D system (p < 0.05), although no significant difference between 2D and 3D systems in task 1 was seen. In both the novice and beginner groups, the 3D system was better for depth perception than horizontal motion. No difference was seen in the expert group in this regard. The 3D HD endoscope was used for the pituitary surgery and was found very useful to identify the spatial relationship of carotid arteries and bony structures. CONCLUSIONS: The use of a 3D neuroendoscope improved depth perception and task performance. Our results suggest that 3D endoscopes could shorten the learning curve of young neurosurgeons and play an important role in both general surgery and neurosurgery.

Electroencephalographic evaluation of cerebral hyperperfusion syndrome following superficial temporal artery-middle cerebral artery anastomosis.

Low-flow bypass, such as superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis, can result in cerebral hyperperfusion syndrome (CHS). The present study evaluated the pathophysiological conditions of CHS through the use of repeated electroencephalography (EEG). Among a total of 22 patients who underwent STA-MCA anastomosis over a course of 4 years, 3 patients were diagnosed with CHS based on clinical symptoms and neuroradiological examinations, including cerebral blood flow evaluation. Case 1 and Case 2 developed CHS on postoperative day 1, when EEG demonstrated focal slow waves on the frontal region of the operated side, indicating cortical dysfunction in these areas. Although prompt recovery of these EEG findings was noted with improvement of the clinical symptoms in Case 1, Case 2 developed an intracranial hemorrhage on postoperative day 5, when EEG clearly depicted persistent nonconvulsive status epilepticus (NCSE) after control of convulsive status epilepticus. In contrast, the clinical onset in Case 3 was delayed to postoperative day 6 and EEG revealed frequent ictal discharges in the operated hemisphere, although convulsive seizures were not apparent. Administration of anticonvulsants was performed after the diagnosis of NCSE, and complete recovery from CHS was achieved. Although the pathophysiology of CHS is cortical dysfunction, ictal hyperperfusion associated with NCSE could be included. The present findings emphasize the importance of repeated EEG examinations in the differential diagnosis of the various types of pathophysiological conditions of CHS.

Usefulness of three-dimensional T1-weighted spoiled gradient-recalled echo and three-dimensional heavily T2-weighted images in preoperative evaluation of spinal dysraphism.

PURPOSE: The aim of this study was to evaluate the usefulness of three-dimensional T1-weighted spoiled gradient-recalled echo (3D T1-GRE) images for the preoperative anatomical evaluation of lumbosacral lipoma, thick filum terminale, and myelomeningocele as a means of compensating for the drawbacks of 3D heavily T2-weighted (3D hT2-W) images. METHODS: Nine patients with lumbosacral lipomas, one patient with tight filum terminale, and five patients with myelomeningoceles were included in this study. 3D T1-GRE images were compared with 3D hT2-W images or conventional magnetic resonance images in terms of delineation of lipomas and other structures in the patients with lipomas and tight filum terminale. For patients with myelomeningoceles, 3D T1-GRE images were compared with 3D hT2-W images in terms of artifacts in the cerebrospinal fluid (CSF) space. RESULTS: The 3D T1-GRE images demonstrated lipomas with good contrast to the spinal cord and CSF space and more clearly delineated the anatomical relationship between lipomas and these structures than did the 3D hT2-W images. The 3D T1-GRE images delineated dural defects through which extradural lipomas penetrated into the intradural space. The 3D T1-GRE images also demonstrated the presence or absence of lipomas in the filum terminale and the absence of artifact in the myelomeningoceles. Furthermore, they were useful for differentiating artifacts observed on the 3D hT2-W images from nerve elements. CONCLUSIONS: The complementary use of 3D T1-GRE and 3D hT2-W images may compensate for the drawbacks of 3D hT2-W images and may eventually improve lesion visualization and surgical decision making.

Surgical techniques for the dissection of encased perforators in giant clinoidal meningiomas.

BACKGROUND: Surgical treatment of giant clinoidal meningiomas remains a challenging task for neurosurgeons. Here, we present details of the surgical techniques for the dissection of encased perforators. METHODS: The dissection of encased perforators is summarized as follows: (1) split the tumor above the encased arteries and perforators; (2) find the entrance and exit points of the perforators, and estimate the running course of the perforators within the tumor; (3) dissect and expose the perforators along the estimated line. CONCLUSIONS: The surgical techniques described in this article will aid in achieving maximum tumor resection while preserving encased perforators.

Facial nerve schwannoma arising from the cerebellopontine angle.

A 74-year-old female suffered hearing disturbance in the right ear persisting for several years, followed by sudden onset of right facial nerve palsy. Her symptoms gradually worsened and neuroradiological imaging revealed a 4-cm cerebellopontine angle (CPA) tumor. Intraoperatively, the tumor was found to originate from the facial nerve. Total removal of the tumor was achieved, followed by a split hypoglossal-facial nerve anastomosis. Facial nerve schwannomas are rare and extremely difficult to preoperatively distinguish from vestibular schwannomas, especially if arising from the CPA and the internal auditory canal. However, preoperative diagnosis of facial nerve schwannomas is important because functional preservation of the facial nerve is more challenging than for vestibular schwannomas. Facial nerve palsy is one of the most unique symptoms in patients with facial nerve schwannomas, but is rare with vestibular schwannomas. Facial nerve schwannomas should be included in the differential diagnosis of CPA tumors with atypical clinical manifestations, and patients should be informed before surgery of the possibility of facial nerve dysfunction and the consequent need for facial nerve graft or reconstruction.