[show abstract][hide abstract] ABSTRACT: Central diabetes insipidus (CDI) is caused by deficiency of arginine vasopressin, an antidiuretic hormone. Patients with CDI manifest polyuria which is usually compensated for by increases in water intake. However, some patients are not able to sense thirst due to the destruction of osmoreceptors in the hypothalamus. These adipsic CDI patients are easily dehydrated and the consequent dehydration could be life-threatening. The objective of this study was to investigate the prognosis of adipsic CDI patients. We have reviewed 149 patients with CDI in three hospitals using databases of the electronic medical recording systems, and examined whether adipsia could affect the morbidity and mortality in CDI patients with multivariable analyses. Twenty-three patients with CDI were adipsic while the remaining 126 patients were non-adipsic. The multivariate analyses showed that the incidence of serious infections which required hospitalization was significantly higher in the adipsic CDI patients compared to that in non-adipsic CDI patients (p <0.001). A total of 6 patients with CDI died during the follow-up (median duration; 60 months, range 1 to 132 months). Four of them were adipsic, three of whom died of infection. The statistical analyses revealed that the risk of death in adipsic CDI patients was significantly higher than in non-adipsic patients (p =0.007). It is thus suggested that adipsic CDI patients were susceptible to serious infections which could be the causes of death.
[show abstract][hide abstract] ABSTRACT: The usefulness of 1.5-T high-field intraoperative magnetic resonance (iMR) imaging during transsphenoidal surgery for functioning pituitary adenomas was retrospectively evaluated based on long-term endocrine remission from the records of 14 patients who underwent transsphenoidal surgery with iMR imaging for functioning pituitary microadenomas and small adenomas located in the intrasellar region. The maximum tumor diameter was 9.3 ± 2.6 mm. Patients were diagnosed with acromegaly (n = 7), prolactinoma (n = 4), and Cushing's disease (n = 3). If iMR imaging detected tumor remnants after resection, the resection cavity was reexamined and further resection was performed. Postoperative endocrine follow-up period was mean 33.7 ± 13.3 months. Tumor remnants were detected after the first resection in seven patients. Further resection was performed in five of these patients, and three achieved long-term endocrine remission. As a result, the overall long-term endocrine remission rate was 78.5% (11/14), instead of the 57.1% (8/14) that would be expected if iMR imaging had not been performed. Long-term endocrine remission had a tendency to be associated with the absence of tumor remnants on the final iMR images, but this was not significant (p = 0.09). Long-term endocrine remission was associated with presence of tumor remnants in the cavernous sinus on the final iMR images (p = 0.03). High-field iMR imaging is useful for depicting tumor remnants after resection, and increased the long-term endocrine remission rate for patients with functioning pituitary microadenomas and small adenomas.
[show abstract][hide abstract] ABSTRACT: Nonfunctioning pituitary macroadenoma (NFMA) is a benign neoplasm that causes visual function disturbances and headaches and can be treated by transsphenoidal surgery (TSS). It is unclear how quality of life (QOL) changes with surgery and which QOL factors are affected by treatment.
The aim is to assess the temporal transition of QOL in NFMA patients undergoing TSS and to identify influential factors. The QOL of NFMA patients who underwent endoscopic TSS was investigated with the short-form 36 (SF-36) health survey questionnaire, general health questionnaire 30 (GHQ30), and numerical rating scale (NRS) of pain at the following three time points: immediately before, 1 month after, and 6 months after surgery.
Twenty-four of 30 patients had visual deterioration. The SF-36 baseline value of visual function-impaired NFMA patients was lower than that of the normal population. SF-36 results showed that physical summary scores decreased at 1 month after the operation, but recovered up to the normal population level by 6 months. Mental summary scores generally increased at 1 month after surgery and remained stable until 6 months later. The GHQ30 results were similar to the SF-36 mental summary scores. The strongest factor related to the QOL was visual function. The amount of pain and the necessity of hormonal replacement were also influencing factors.
The QOL of NFMA patients is affected both physically and mentally by surgical treatment and symptoms. This QOL assessment is important for planning treatment strategies.
[show abstract][hide abstract] ABSTRACT: Endoscope biopsy guided navigation for intra-parenchymal lesions is safe and effective, but determination of the entry point and trajectory of the endoscopic biopsy is less clear. We describe preoperative planning based on stereotactic methods, and achieving the plan using several techniques. The preoperative planning was based on stereotactic methods such as determining target, entry point, and trajectory. A transparent sheath was advanced under guidance of the navigation system and specimens collected under visual endoscopic monitoring. After collecting specimens, intraoperative magnetic resonance imaging was performed for confirming accurate sampling. Correct specimens were obtained in 6 cases as confirmed by intraoperative magnetic resonance imaging. The histological diagnoses were diffuse large B-cell type malignant lymphoma (n = 3), astrocytoma (n = 1), glioblastoma (n = 1), and inflammatory changes without neoplastic cells (n = 1). No postoperative intracranial hemorrhage or other operative complications occurred. Preoperative planning based on stereotactic methods and procedures guided by navigation systems can achieve endoscopic biopsy for intraparenchymal lesions safely and accurately.
[show abstract][hide abstract] ABSTRACT: Mouse models have been widely used in developing therapies for human brain tumors. However, surgical techniques such as bone drilling and skin suturing to create brain tumors in adult mice are still complicated. The aim of this study was to establish a simple and accurate method for intracranial injection of cells or other materials into mice.
The authors performed micro CT scans and skull dissection to assess the anatomical characteristics of the mouse postglenoid foramen. They then used xenograft and genetically engineered mouse models to evaluate a novel technique of percutaneous intracranial injection via the postglenoid foramen. They injected green fluorescent protein-labeled U87MG cells or virus-producing cells into adult mouse brains via the postglenoid foramen and identified the location of the created tumors by using bioluminescence imaging and histological analysis.
The postglenoid foramen was found to be a well-conserved anatomical structure that allows percutaneous injection into the cerebrum, cerebellum, brainstem, and basal cistern in mice. The mean (± SD) time for the postglenoid foramen injection technique was 88 ± 15 seconds. The incidence of in-target tumor formation in the xenograft model ranged from 80% to 100%, depending on the target site. High-grade gliomas were successfully developed by postglenoid foramen injection in the adult genetically engineered mouse using virus-mediated platelet-derived growth factor B gene transfer. There were no procedure-related complications.
The postglenoid foramen can be used as a needle entry site into the brain of the adult mouse. Postglenoid foramen injection is a less invasive, safe, precise, and rapid method of implanting cells into the adult mouse brain. This method can be applied to both orthotopic xenograft and genetically engineered mouse models and may have further applications in mice for the development of therapies for human brain tumors.
Journal of Neurosurgery 12/2011; 116(3):630-5. · 3.15 Impact Factor
[show abstract][hide abstract] ABSTRACT: Visualization of endolymphatic hydrops has been performed using magnetic resonance imaging (MRI) after intratympanic or intravenous gadolinium (Gd) injection. Our recent findings indicate that just as the prevalence of asymptomatic glaucoma is greater than that of symptomatic glaucoma, there are also many cases of asymptomatic endolymphatic hydrops. It is assumed that the asymptomatic endolymphatic hydrops that precedes Ménière's disease is found more frequently using MRI than with other techniques. Gd in the inner ear moves into the cerebrospinal fluid (CSF) via the internal auditory meatus. Gd enhancement is also recognized in the ocular fluid after the intravenous Gd administration. In this paper, the relationships between CSF, ocular fluid and inner ear fluid are reviewed. The central nervous system, eye and inner ear contain specialized extracellular fluids that are essential for maintaining their function: CSF, ocular fluid consisting of vitreous humor and aqueous humor, and inner ear fluid consisting of perilymph and endolymph. Abnormal accumulation of or pressure elevation in these fluids is associated with hydrocephalus, glaucoma and Ménière's disease, respectively. The dura mater and the arachnoid membrane of the optic nerve canal and inner ear meatus are very close to the eye and the inner ear, respectively. It has been reported that low CSF pressure is associated with glaucoma and endolymphatic hydrops. In glaucoma and Ménière's disease, nerve damage to ganglion cells rather than damage of the sensory cells is directly associated with progression of the disease. Retinal ganglion cells in glaucoma and spiral ganglion cells in Ménière's disease are targets of the abnormal accumulation of, or increased pressure in, the extracellular fluid, just as neurons are damaged in hydrocephalus. Studies on hydrocephalus, glaucoma and Ménière's disease as a group may deepen our understanding of each disease.
[show abstract][hide abstract] ABSTRACT: This paper proposes a rapid method for compensating registration error between the tracker and the endoscope in a flexible neuroendoscopic surgery navigation system, as well as evaluates the accuracy of the proposed method. Recently, flexible neuroendoscopic surgery navigation systems have been developed utilizing an electromagnetic tracker (EMT). In such systems, an electromagnetic tracker sensor is fixed at the tip of a flexible endoscope to get the position and the orientation of the endoscope camera by using the relationship between the camera and the sensor. Usually, the relationship is estimated by a registration method using a calibration chart. Then, virtual images corresponding to real endoscopic views are generated by using the position and orientation of the camera. However, in the clinical application, the sensor has to be re-fixed before or during the surgery due to its disinfection or breakage. Although the sensor can be re-fixed at the same position as the registered position, it is difficult to ensure the roll of sensor in the same because the senor is a cylinder. Furthermore, the sensor can also be rotated by the operation of tools during surgery. As a result, the virtual images will be rotated and become greatly different from the real endoscopic views. In this case, the relationship between camera and sensor has to be re-estimated by a registration method or manually, which makes the operation of endoscope complicated and nonfeasible. In order to overcome this problem, we proposed a rapid method for compensating the rotational error between real and virtual cameras using the epipolar geometry. In this study, various experiments of the method are performed in order to evaluate and to improve its accuracy. Experimental results suggested estimation accuracy can be improved by reducing the relative error of EMT outputs, and it is necessary to ensure the quality of images which are used in the estimation.
[show abstract][hide abstract] ABSTRACT: Intradural chordomas are rare and have been considered benign owing to the feasibility of complete resection and the display of lesser aggressive biologic behavior than typical chordomas.
We herein reported 2 cases of intradural cranial chordoma with aggressive biologic behavior. A tumor (anti-Ki-67 monoclonal antibody [MIB-1], 13.9%) in a 59-year-old woman was strongly adherent to the brainstem and involved the basilar artery and its branches. After subtotal removal, the remnant tumor was treated with stereotactic radiotherapy. A tumor (MIB-1, 6.2%) in a 75-year-old woman repeatedly recurred even after initial gross total removal. The recurrent chordomas were treated with γ-knife radiosurgery.
The cases presented in this study indicate that intradural chordomas can also be aggressive such as typical chordomas. Long-term follow-ups with a large number of patients with this condition are essential for elucidating the prognosis of intradural chordomas.
World Neurosurgery 03/2010; 73(3):194-7; discussion e31. · 1.77 Impact Factor
[show abstract][hide abstract] ABSTRACT: A 51-year-old man was referred to the Department of Cardiology in our hospital due to severe congestive heart failure and ventricular arrhythmias in March 2008. He had repeated ventricular tachycardia for years and the left ventricular ejection fraction (EF) was 11% on admission. A myocardial biopsy revealed that over 50% cardiomyocytes were replaced by fibrosis. Due to the typical acromegalic features, he was referred to the endocrinology department and diagnosed as acromegaly. He was treated with octreotide for 8 months followed by trans-sphenoidal surgery. The plasma levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) decreased by octreotide and normalised by surgery after which the cardiac function improved drastically. The current case demonstrates that cardiac dysfunction in acromegaly could be recovered by normalisation of GH and IGF-1 even in the presence of severe fibrosis in the myocardium.
[show abstract][hide abstract] ABSTRACT: The authors have developed a novel intraoperative neuronavigation with 3-dimensional (3D) virtual images, a 3D virtual navigation system, for neuroendoscopic surgery. The present study describes this technique and clinical experience with the system.
Preoperative imaging data sets were transferred to a personal computer to construct virtual endoscopic views with image segmentation software. An electromagnetic tracker was used to acquire the position and orientation of the tip of the neuroendo-scope. Virtual endoscopic images were interlinked to an electromagnetic tracking system and demonstrated on the navigation display in real time. Accuracy and efficacy of the 3D virtual navigation system were evaluated in a phantom test and on 5 consecutive patients undergoing neuroendoscopic surgery.
Virtual navigation views were consistent with actual endoscopic views and trajectory in both phantom testing and clinical neuroendoscopic surgery. Anatomic structures that can affect surgical approaches were adequately predicted with the virtual navigation system. The virtual semitransparent view contributed to a clear understanding of spatial relationships between surgical targets and surrounding structures. Surgical procedures in all patients were performed while confirming with virtual navigation. In neurosurgery with a flexible neuroscope, virtual navigation also demonstrated anatomic structures in real time.
The interactive method of intraoperative visualization influenced the decision-making process during surgery and provided useful assistance in identifying safe approaches for neuroendoscopic surgery. The magnetically guided navigation system enabled navigation of surgical targets in both rigid and flexible endoscopic surgeries.
[show abstract][hide abstract] ABSTRACT: Chordomas are locally destructive tumors with high rates of recurrence, and therapeutic strategies remain controversial. This study analyzed long-term outcomes for clival chordomas after initial aggressive surgical resection and gamma knife radiosurgery for recurrence and investigated clinical factors predicting recurrence.
Clinical records were reviewed for 19 consecutive patients (11 men, 8 women; mean age, 43.1 years) with clival chordoma who underwent initial surgical resection using skull base approaches (mean follow-up after surgical resection, 87.2 months). All tumors were aggressively removed, along with the surrounding bone. Four patients were treated with radiotherapy after surgical resection.Recurrent lesions were treated with gamma knife radio surgery or reoperation. Factors predicting tumor recurrence were analyzed, including age, tumor extension, extent of resection and MIB-1 labeling index. Patient status was evaluated using the Karnofsky performance scale (KPS).
Tumor resection was total, subtotal and partial in 14, 4 and 1 patients, respectively. Tumors recurred in 11 patients. Overall, 2- and 5-year progression-free survival rates were 77.9% and 47.9%, respectively. The MIB-1 labeling index was independently associated with recurrence.The optimum cutoff point for the MIB-1 labeling index was 3.44%. All recurrent tumors were totally resected or controlled by gamma knife (mean follow-up after recurrence, 71.2 months). All patients survived and were active (mean KPS at final follow-up, 89.5%).
Long-term control of clival chordomas was achieved. Recurrent tumors were controlled with gamma knife radiosurgery, since lesions were localized and small after initial aggressive resection. The MIB-1 labeling index can provide important information for predicting tumor recurrence.
[show abstract][hide abstract] ABSTRACT: We retrospectively reviewed characteristics of patients with neurofibromatosis type 2 to identify factors predicting further growth of bilateral vestibular schwannomas. Subjects comprised 27 neurofibromatosis type 2 patients with 54 vestibular schwannomas, followed for 24-204 months (mean, 86 months). This study investigated factors predictive of vestibular schwannoma growth in neurofibromatosis type 2. Features distinguishing actively growing from quiescent VS were determined for untreated course (28 vestibular schwannomas) and posttreatment course (including either resection or radiosurgery; 33 vestibular schwannomas). A general estimation equation was used to identify factors affecting tumor growth. During the untreated course, 19 vestibular schwannomas showed growth and 9 vestibular schwannomas were stable. No factors predictive of growth were shown. During the posttreatment course (23 surgical resections, ten radiosurgeries), ten treatments were followed by growth and 23 were followed by stability, with growth showing an association with onset at an early age (p = 0.007). Multivariate analysis identified no factors predictive of growth. After treatment, close follow-up is warranted for patients with onset at an early age.
[show abstract][hide abstract] ABSTRACT: A 67-year-old man presented with a rare case of cavernous sinus thrombophlebitis (CST) caused by Porphyromonas gingivalis with abscess formation extending to the orbital cavity. Neuroimaging demonstrated a cystic lesion in the right cavernous sinus that was hyperintense on diffusion-weighted imaging. The patient was successfully treated with surgical drainage and antibiotic administration. CST is rare and often has a fulminant progression with high rates of morbidity and mortality. The differential diagnosis of cavernous sinus lesions should include CST. Early recognition and differentiation from other diseases with aggressive medical and possible surgical intervention are necessary to reduce mortality and long-term sequelae. Diffusion-weighted imaging is useful for the early recognition and differentiation of CST from other diseases.
[show abstract][hide abstract] ABSTRACT: Initial experiences are reviewed in an integrated operation theater equipped with an intraoperative high-field (1.5 T) magnetic resonance (MR) imager and neuro-navigation (BrainSUITE), to evaluate the indications and limitations. One hundred consecutive cases were treated, consisting of 38 gliomas, 49 other tumors, 11 cerebrovascular diseases, and 2 functional diseases. The feasibility and usefulness of the integrated theater were evaluated for individual diseases, focusing on whether intraoperative images (including diffusion tensor imaging) affected the surgical strategy. The extent of resection and outcomes in each histological category of brain tumors were examined. Intraoperative high-field MR imaging frequently affected or modified the surgical strategy in the glioma group (27/38 cases, 71.1%), but less in the other tumor group (13/49 cases, 26.5%). The surgical strategy was not modified in cerebrovascular or functional diseases, but the success of procedures and the absence of complications could be confirmed. In glioma surgery, subtotal or greater resection was achieved in 22 of the 31 patients (71%) excluding biopsies, and intraoperative images revealed tumor remnants resulting in the extension of resection in 21 of the 22 patients (95.4%), the highest rate of extension among all types of pathologies. The integrated neuro-navigation improved workflow. The best indication for intraoperative high-field MR imaging and integrated neuro-navigation is brain tumors, especially gliomas, and is supplementary in assuring quality in surgery for cerebrovascular or functional diseases. Immediate quality assurance is provided in several types of neurosurgical procedures.
[show abstract][hide abstract] ABSTRACT: Intraoperative microneurography (enabling direct measurement of sympathetic outflow) and laser Doppler flowmetry were used to measure skin sympathetic nerve activity (SSNA) and skin blood flow (SBF) as indicators of hypothalamic damage during resection of 12 suprasellar tumors, 6 craniopharyngiomas, 4 meningiomas, 1 pituitary adenoma, and 1 germ cell tumor. SSNA was measured from a tungsten microelectrode inserted into the peroneal nerve, and SBF was measured from the foot innervated by the peroneal nerve. SBF reduction was induced by nociceptive procedures and non-nociceptive procedures before tumor exposure, on exposed tumors, and directly on the hypothalamus. SSNA could be reliably recorded in only 4 patients because of technical difficulties. In these patients, SSNA bursts appeared, followed by SBF reduction. The number of SSNA bursts was 37% to 100% of the number of SBF reduction events. Various surgical procedures involving painful stimuli or mechanical stress on the hypothalamus induced SSNA bursts and SBF reduction. The present findings suggest that SSNA and SBF can be used to detect sympathetic nerve activity, as an indicator of hypothalamic function, during neurosurgical procedures.
[show abstract][hide abstract] ABSTRACT: This paper presents an improved method for compensating ultra-tiny electromagnetic tracker (UEMT) outputs and its application to a flexible neuroendoscopic surgery navigation system. Recently, UEMT is widely used in a surgical navigation system using a flexible endoscope to obtain the position and the orientation of an endoscopic camera.However, due to the distortion of the electromagnetic field, the accuracy of such UEMT system becomes low. Several research groups have presented methods for compensating UEMT outputs that are deteriorated by ferromagnetic objects existing around the UEMT. These compensation methods firstly acquired positions and orientations (sample data) by sweeping a special tool (hybrid tool) having a UEMT and an optical tracker (OT) in free-hand. Then a polynomial compensating UEMT outputs is computed from both outputs. However, these methods have following problems: 1) Compensation function is obtained as a function of position, and orientation information is not used in compensation. 2) Although we need to slowly move the hybrid tool to obtain better compensation results, this leads increase of time. To overcome such problems, this paper presents a UEMT-output compensation function that is a function of not only position but also orientation. Also, a new sweeping method of the hybrid tool is proposed in order to reduce the sweeping time required for obtaining sample data. We evaluated the accuracy and feasibility of the proposed method by experiments in an OpenMR operating room. According to the result of experiments, the accuracy of the compensation method is improved about 20% than that of the previous method. We implemented the proposed method in a navigation system for flexible neuroendoscopic surgery and performed a phantom test and several clinical application tests. The result showed the proposed method is efficient for UEMT output compensation and improves accuracy of a flexible neuroendoscopic surgery system.
[show abstract][hide abstract] ABSTRACT: The authors describe direct measurement of optic nerve blood flow and examine application of such monitoring to detect optic nerve ischemia during parasellar tumor surgery. Twenty-six patients requiring surgery for parasellar tumors were evaluated prospectively. Ophthalmologic examination was performed before and after surgery. The optic nerve blood flow was measured using a laser Doppler flowmeter before tumor dissection (initial ONBF) and after tumor removal (final ONBF). The waveform was analyzed by a data acquisition system. In 16 patients, initial ONBF could be measured (22 nerves; 8.9±0.9 ml/100 g/min). Final ONBF could be determined in all 26 patients (42 nerves; 10.8±0.7 ml/100 g/min). In the 22 nerves with initial measurements, final ONBF (11.3±0.6 ml/100 g/min) was significantly increased (p<0.01). In 6 patients whose optic canal was unroofed, the optic nerve blood flow did not change immediately; nonetheless, an increase was prominent in the final phase (p<0.05). In another 6 patients, a small vessel adjacent to the optic nerve was temporarily occluded. The optic nerve blood flow was reduced demonstrably in 3 and recovered quickly after reperfusion. Intraoperative optic nerve blood flow measurement may be useful as a real-time monitoring for prediction and prevention of intraoperative optic nerve ischemia.