Automatic assessment of disproportionately enlarged subarachnoid-space hydrocephalus from 3D MRI using two deep learning models.

Background: Disproportionately enlarged subarachnoid-space hydrocephalus (DESH) is a key feature for Hakim disease (idiopathic normal pressure hydrocephalus: iNPH), but subjectively evaluated. To develop automatic quantitative assessment of DESH with automatic segmentation using combined deep learning models. Methods: This study included 180 participants (42 Hakim patients, 138 healthy volunteers; 78 males, 102 females). Overall, 159 three-dimensional (3D) T1-weighted and 180 T2-weighted MRIs were included. As a semantic segmentation, 3D MRIs were automatically segmented in the total ventricles, total subarachnoid space (SAS), high-convexity SAS, and Sylvian fissure and basal cistern on the 3D U-Net model. As an image classification, DESH, ventricular dilatation (VD), tightened sulci in the high convexities (THC), and Sylvian fissure dilatation (SFD) were automatically assessed on the multimodal convolutional neural network (CNN) model. For both deep learning models, 110 T1- and 130 T2-weighted MRIs were used for training, 30 T1- and 30 T2-weighted MRIs for internal validation, and the remaining 19 T1- and 20 T2-weighted MRIs for external validation. Dice score was calculated as (overlapping area) × 2/total area. Results: Automatic region extraction from 3D T1- and T2-weighted MRI was accurate for the total ventricles (mean Dice scores: 0.85 and 0.83), Sylvian fissure and basal cistern (0.70 and 0.69), and high-convexity SAS (0.68 and 0.60), respectively. Automatic determination of DESH, VD, THC, and SFD from the segmented regions on the multimodal CNN model was sufficiently reliable; all of the mean softmax probability scores were exceeded by 0.95. All of the areas under the receiver-operating characteristic curves of the DESH, Venthi, and Sylhi indexes calculated by the segmented regions for detecting DESH were exceeded by 0.97. Conclusion: Using 3D U-Net and a multimodal CNN, DESH was automatically detected with automatically segmented regions from 3D MRIs. Our developed diagnostic support tool can improve the precision of Hakim disease (iNPH) diagnosis.

Simultaneous boost radiotherapy versus conventional dose radiotherapy for patients with newly diagnosed glioblastoma: a multi-institutional analysis.

We compared survival outcomes of high-dose concomitant boost radiotherapy (HDCBRT) and conventional dose radiotherapy (CRT) for newly diagnosed glioblastoma (GB). Patients treated with intensity-modulated radiation therapy for newly diagnosed GB were included. In HDCBRT, specific targets received 69, 60, and 51 Gy in 30 fractions, while 60 Gy in 30 fractions was administered with a standard radiotherapy method in CRT. Overall survival (OS) and progression-free survival (PFS) were compared using the Log-rank test, followed by multivariate Cox analysis. The inverse probability of treatment weighting (IPTW) method was also applied to each analysis. Among 102 eligible patients, 45 received HDCBRT and 57 received CRT. With a median follow-up of 16 months, the median survival times of OS and PFS were 21 and 9 months, respectively. No significant differences were observed in OS or PFS in the Kaplan-Meier analyses. In the multivariate analysis, HDCBRT correlated with improved OS (hazard ratio, 0.49; 95% confidence interval, 0.27-0.90; P = 0.021), and this result remained consistent after IPTW adjustments (P = 0.028). Conversely, dose suppression due to the proximity of normal tissues and IMRT field correlated with worse OS and PFS (P = 0.008 and 0.049, respectively). A prospective study with a stricter protocol is warranted to validate the efficacy of HDCBRT for GB.

Preventive effect of intermittent cerebrospinal fluid drainage for secondary chronic hydrocephalus after aneurysmal subarachnoid hemorrhage.

BACKGROUND: The efficacy of intermittent cerebrospinal fluid (CSF) drainage compared with that of continuous CSF drainage in patients with subarachnoid hemorrhage (SAH) remains undetermined to date. Therefore, we investigated whether intermittent CSF drainage is effective in reducing secondary chronic hydrocephalus (sCH) after aneurysmal SAH. METHODS: Overall, 204 patients (69 men and 135 women) treated for aneurysmal SAH between 2007 and 2022 were included in this study. Following SAH onset, 136 patients were managed with continuous CSF drainage, whereas 68 were managed with intermittent CSF drainage. Logistic regression analyses were used to calculate the age-adjusted and multivariate odds ratios for the development of sCH. The Cox proportional hazards regression model were used to compare the effects of intermittent and continuous CSF drainage on sCH development. RESULTS: Overall, 96 patients developed sCH among the 204 patients with SAH. In total, 74 (54.4%) of the 136 patients managed with continuous CSF drainage developed sCH, whereas 22 (32.4%) of the 68 patients managed with intermittent CSF drainage developed sCH. This demonstrated that the rate of sCH development was significantly lower among patients managed with intermittent CSF drainage. Compared with continuous CSF drainage, intermittent CSF drainage exhibited a multivariate odds ratio (95% confidential interval) of 0.25 (0.11-0.57) for sCH development. Intermittent CSF drainage was more effective (0.20, 0.04-0.95) in patients with severe-grade SAH than in those with mild-grade SAH (0.33, 0.12-0.95). Intermittent CSF drainage was ineffective in patients with acute hydrocephalus (8.37, 0.56-125.2), but it was effective in patients without acute hydrocephalus (0.11, 0.04-0.31). CONCLUSIONS: Compared with continuous CSF drainage, intermittent drainage is more effective in reducing sCH after aneurysmal SAH. Although intermittent drainage was ineffective in cases of co-occurrence of acute hydrocephalus, it was effective in reducing sCH development regardless of the severity of initial symptoms at SAH onset.

SEGA-like circumscribed astrocytoma in a non-NF1 patient, harboring molecular profile of GBM. A case report.

Subependymal giant cell astrocytoma (SEGA) is a low-grade periventricular tumor that is closely associated with tuberous sclerosis complex (TSC). SEGA typically arises during the first two decades of life and rarely arises after the age of 20-25 years. Nevertheless, it has also been reported that glioma histologically resembling SEGA, so-called SEGA-like astrocytoma, can arise in neurofibromatosis type 1 (NF1) patients, even in the elderly. Herein, we report a case of SEGA-like circumscribed astrocytoma arising in the lateral ventricle of a 75-year-old woman. Whole-exome sequencing revealed a somatic variant of NF1. Methylation array analysis led to a diagnosis of "methylation class glioblastoma, IDH-wildtype, mesenchymal-type (GBM, MES)" with a high calibrated score (0.99). EGFR amplification, CDKN2A/B homozygous deletion, chromosomal +7/-10 alterations, and TERT promoter mutation, typical molecular abnormalities usually found in GBM, were also observed. While most reported cases of SEGA-like astrocytoma have arisen in NF1 patients, the patient was neither TSC nor NF1. Near total removal was accomplished with endoscopic cylinder surgery. At the 36-month follow-up, there was no tumor recurrence without adjuvant therapies. This clinical behavior did not match GBM. SEGA-like astrocytoma of the elderly is rare, and this is the oldest case reported so far. In addition, high-grade molecular features found in circumscribed tumor remain unclear. Further investigations among larger series are needed for clarifying the underlying molecular mechanisms.

Japanese nationwide questionnaire survey on delayed cerebral infarction due to vasospasm after subarachnoid hemorrhage.

Background and purpose: Various prophylactic drugs for cerebral vasospasm and delayed cerebral infarction (DCI) after subarachnoid hemorrhage (SAH) have been used in Japan. To investigate the treatment trends for cerebral vasospasm and frequency of DCI after SAH throughout Japan in 2021. Methods: In 2021 we conducted an anonymous questionnaire survey on management for preventing cerebral vasospasm after aneurysmal SAH, and the frequency of DCI. The questionnaire was emailed to 955 certified neurosurgeons at 553 hospitals in Japan. Of them, 162 hospitals (29% response rate) responded to the questionnaire. Of these, 158 were included in this study, while four hospitals that responded insufficiently were excluded. The efficacy of treatments for reducing DCI were examined through a logistic regression analysis. Results: Among 3,093 patients treated with aneurysmal SAH, 281 patients (9.1%) were diagnosed with DCI related to cerebral vasospasm. Coil embolization had significantly lower DCI frequency (6.9%), compared to microsurgical clipping (11.8%, odds ratio, 0.90; 95% confidential intervals, 0.84-0.96; P, 0.007). In addition, cilostazol administration was associated with significantly lower DCI frequency (0.48; 0.27-0.82; 0.026). The efficacy of cilostazol in reducing DCI remained unchanged after adjustment for covariates. The most effective combination of multiple prophylactic drugs in reducing DCI related to cerebral vasospasm was cilostazol, fasudil, and statin (0.38; 0.22-0.67; 0.005). Conclusions: This study elucidated the trends in prophylactic drugs to prevent cerebral vasospasm and frequency of DCI after aneurysmal SAH in Japan. Coil embolization and cilostazol administration showed effectiveness in reducing DCI related to cerebral vasospasm in 2021.

Aging and Sex Differences in Brain Volume and Cerebral Blood Flow.

How do regional brain volume ratios and cerebral blood flow (CBF, mL/min) change with aging, and are there sex differences? This study aimed to comprehensively evaluate the relationships between regional brain volume ratios and CBF in healthy brains. The study participants were healthy volunteers who underwent three-dimensional T1-weighted MRI, time-of-flight MR angiography, and four-dimensional (4D) flow MRI between 2020 and 2022. The brain was automatically segmented into 21 brain subregions from 3D T1-weighted MRI, and CBF in 16 major intracranial arteries were measured by 4D flow MRI. The relationships between segmented brain volume ratios and CBFs around the circle of Willis were comprehensively investigated in each decade and sex. This study included 129 healthy volunteers (mean age ± SD, 48.2 ± 16.8; range, 22-92 years; 43 males and 86 females). The association was strongest between the cortical gray matter volume ratio and total outflow of the intracranial major arteries distal to the circle of Willis (Pearson's correlation coefficient, r: 0.425). In addition, the mean flow of the total inflow and outflow around the circle of Willis were significantly greater in women than men, and significant left-right differences were observed in CBFs even on the peripheral side of the circle of Willis. Moreover, the correlation was strongest between the left cortical gray matter volume ratio and the combined flows of the left anterior and posterior cerebral arteries distal to the circle of Willis (r: 0.486). There was a trend toward greater total intracranial CBF, especially among women in their 40s and younger, who had a larger cortical gray matter volume. This finding may be one of the reasons for the approximately twofold higher incidence of cerebral aneurysms and subarachnoid hemorrhage, and a threefold higher incidence of migraine headaches.

Secular trends and features of thalamic hemorrhages compared with other hypertensive intracerebral hemorrhages: an 18-year single-center retrospective assessment.

Introduction: Trends regarding the locations of hypertensive cerebral hemorrhages are unclear. To clarify hypertensive hemorrhage trends, we investigated intracerebral hemorrhages (ICHs) over an 18-year period, focusing on thalamic hemorrhages compared with other sites of hemorrhages. Methods: We reviewed the cases of patients hospitalized for hypertensive ICH in 2004-2021 at our hospital; 1,320 eligible patients were registered with a primary ICH/intraventricular hemorrhage. After exclusion criteria were applied, we retrospectively analyzed 1,026 hypertensive ICH cases. Results: The proportions of thalamic and subcortical hemorrhages increased over the 18-year period, whereas putaminal hemorrhage decreased. Multivariate logistic regression analyses revealed that for thalamic hemorrhage, ≥200 mmHg systolic blood pressure (p = 0.031), bleeding <15 mL (p = 0.001), and higher modified Rankin scale (mRS) score ≥ 4 at discharge (p = 0.006) were significant variables in the late period (2013-2021) versus the early period (2004-2012), whereas for putaminal hemorrhage, significant factors in the late period were triglyceride <150 mg/dL (p = 0.006) and mRS score ≥ 4 at discharge (p = 0.002). Among the features of the thalamic hemorrhages in the late period revealed by our group comparison with the putaminal and subcortical hemorrhages, the total and subcortical microbleeds were more notable in the thalamic hemorrhages than in the other two types of hemorrhage, whereas cerebellar microbleeds were more prominent when compared only with subcortical hemorrhages. Discussion: Our findings revealed an increasing trend for thalamic hypertensive hemorrhage and a decreasing trend for putaminal hemorrhage. The thalamic hemorrhage increase was observed in both young and older patients, regardless of gender. The main features of thalamic hemorrhage in the late period versus the early period were decrease in larger hemorrhage (≥15 mL) and an increase in cases with higher systolic blood pressure (at least partially involved a small number of untreated hypertensive patients who developed major bleeding). The total and subcortical microbleeds were more notable in the thalamic hemorrhages of the late period than in the putaminal and subcortical hemorrhages. These results may contribute to a better understanding of the recent trends of hypertensive ICHs and may help guide their appropriate treatments for this condition.

Age-Related Changes in Cerebrospinal Fluid Dynamics in the Pathogenesis of Chronic Hydrocephalus in Adults.

Cerebrospinal fluid (CSF) dynamics has dramatically changed in this century. In the latest concept of CSF dynamics, CSF is thought to be produced mainly from interstitial fluid excreted from the brain parenchyma and is absorbed in the meningeal lymphatics. Moreover, CSF does not always flow from the ventricles to the subarachnoid space unidirectionally through the foramina of Magendie and Luschka. In an environment of increased intracranial CSF in idiopathic normal pressure hydrocephalus, CSF freely moves through the inferior choroidal point of the choroidal fissure, which interfaces between the inferior horn of the lateral ventricles and the ambient cistern and through the velum interpositum between the third ventricle and the quadrigeminal cistern. The structure of the hippocampus adjacent to the inferior part of the choroidal fissure may be important in preventing the accumulation of waste products in the hippocampus. A recent imaging technology for CSF dynamics, such as four-dimensional flow and intravoxel incoherent motion magnetic resonance imaging, can visualize and quantify the pulsatile complex CSF motion in clinical usage. We present the current concepts of CSF dynamics with advanced magnetic resonance imaging techniques, which will be helpful in the management and understanding of the pathogenesis of chronic hydrocephalus in adults.

Minimally invasive treatment for glioblastoma through endoscopic surgery including tumor embolization when necessary: a technical note.

Background: Although there have been some reports on endoscopic glioblastoma surgery, the indication has been limited to deep-seated lesions, and the difficulty of hemostasis has been a concern. In that light, we attempted to establish an endoscopic procedure for excision of glioblastoma which could be applied even to hypervascular or superficial lesions, in combination with pre-operative endovascular tumor embolization. Methods: Medical records of six consecutive glioblastoma patients who received exclusive endoscopic removal between September and November 2020 were analyzed. Preoperative tumor embolization was performed in cases with marked tumor stain and proper feeder arteries having an abnormal shape, for instance, tortuous or dilated, without passing through branches to the normal brain. Endoscopic tumor removal through a key-hole craniotomy was performed by using an inside-out excision for a deep-seated lesion, with the addition of an outside-in extirpation for a shallow portion when needed. Results: Endoscopic removal was successfully performed in all six cases. Before resection, endovascular tumor embolization was performed in four cases with no resulting complications, including ischemia or brain swelling. Gross total resection was achieved in three cases, and near total resection in the other three cases. Intraoperative blood loss exceeded 1,000 ml in only one case, whose tumor showed a prominent tumor stain but no proper feeder artery for embolization. In all patients, a smooth transition to adjuvant therapy was possible with no surgical site infection. Conclusion: Endoscopic removal for glioblastoma was considered to be a promising procedure with minimal invasiveness and a favorable impact on prognosis.

Tightened Sulci in the High Convexities as a Noteworthy Feature of Idiopathic Normal Pressure Hydrocephalus.

OBJECTIVE: The presence of tightened sulci in the high-convexities (THC) is a key morphological feature for the diagnosis of idiopathic normal pressure hydrocephalus (iNPH), but the exact localization of THC has yet to be defined. The purpose of this study was to define THC and compare its volume, percentage, and index between iNPH patients and healthy controls. METHODS: According to the THC definition, the high-convexity part of the subarachnoid space was segmented and measured the volume and percentage from the 3D T1-weighted and T2-weighted magnetic resonance images in 43 patients with iNPH and 138 healthy controls. RESULTS: THC was defined as a decrease in the high-convexity part of the subarachnoid space located above the body of the lateral ventricles, with anterior end on the coronal plane perpendicular to the anterior commissure-posterior commissure (AC-PC) line passing through the front edge of the genu of corpus callosum, the posterior end in the bilateral posterior parts of the callosomarginal sulci, and the lateral end at 3 cm from the midline on the coronal plane perpendicular to the AC-PC line passing through the midpoint between AC and PC. Compared to the volume and volume percentage, the high-convexity part of the subarachnoid space volume per ventricular volume ratio < 0.6 was the most detectable index of THC on both 3D T1-weighted and T2-weighted magnetic resonance images. CONCLUSIONS: To improve the diagnostic accuracy of iNPH, the definition of THC was clarified, and high-convexity part of the subarachnoid space volume per ventricular volume ratio <0.6 proposed as the best index for THC detection in this study.

Endoscope-Controlled High Frontal Approach for Dural Arteriovenous Fistula in Anterior Cranial Fossa.

BACKGROUND: Currently, surgical obliterations are a mainstay for treating dural arteriovenous fistula (DAVF) in the anterior cranial fossa (ACF), which has high risks of hemorrhage and functional disorder. By introducing an endoscope into a high frontal approach and utilizing its advantages, we attempted to establish it as a new surgical procedure that eliminates the drawbacks of various approaches that have been used to date. METHODS: By using 30 clinical datasets of venous-phase head computed tomography angiogram, measurements and comparisons on a 3-dimensional workstation were performed to identify the appropriate positioning of keyhole craniotomy for endoscope-controlled high frontal approach (EHFA). Based on these data, a cadaver-based surgery was simulated to verify the feasibility of EHFA and develop an efficient procedure. RESULTS: In EHFA, though raising the position of the keyhole craniotomy made the operative field deeper, significant advantages were obtained in the angle between the operative axis and the medial-anterior cranial base and the amount of bone removal required at the anterior edge of craniotomy. Minimally invasive EHFA, performed through a keyhole craniotomy without opening the frontal sinus, proved to be feasible on 10 sides of 5 cadaver heads. Moreover, 3 patients with DAVF in ACF were successfully treated by clipping the fistula via EHFA. CONCLUSIONS: EHFA, which provided a direct corridor to the medial ACF at the level of the foramen cecum and crista galli and the minimum necessary operative field, was found to be a suitable procedure for clipping the fistula of DAVF in ACF.

Clinical utility of paced finger tapping assessment in idiopathic normal pressure hydrocephalus.

Background: The Finger Tapping (F-T) test is useful for assessing motor function of the upper limbs in patients with idiopathic normal pressure hydrocephalus (iNPH). However, quantitative evaluation of F-T for iNPH has not yet been established. The purpose of this study was to investigate the usefulness of the quantitative F-T test and optimal measurement conditions as a motor evaluation and screening test for iNPH. Methods: Sixteen age-matched healthy controls (mean age 73 ± 5 years; 7/16 male) and fifteen participants with a diagnosis of definitive iNPH (mean age 76 ± 5 years; 8/15 male) completed the study (mean ± standard deviation). F-T performance of the index finger and thumb was quantified using a magnetic sensing device. The performance of repetitive F-T by participants was recorded in both not timing-regulated and timing-regulated conditions. The mean value of the maximum amplitude of F-T was defined as M-Amplitude, and the mean value of the maximum velocity of closure of F-T was defined as cl-Velocity. Results: Finger Tapping in the iNPH group, with or without timing control, showed a decrease in M-Amplitude and cl-Velocity compared to the control group. We found the only paced F-T with 2.0 Hz auditory stimuli was found to improve both M-Amplitude and cl-Velocity after shunt surgery. Conclusion: The quantitative assessment of F-T with auditory stimuli at the rate of 2.0 Hz may be a useful and potentially supplemental screening method for motor assessment in patients with iNPH.

Quantitative Gait Feature Assessment on Two-Dimensional Body Axis Projection Planes Converted from Three-Dimensional Coordinates Estimated with a Deep Learning Smartphone App.

To assess pathological gaits quantitatively, three-dimensional coordinates estimated with a deep learning model were converted into body axis plane projections. First, 15 healthy volunteers performed four gait patterns; that is, normal, shuffling, short-stepped, and wide-based gaits, with the Three-Dimensional Pose Tracker for Gait Test (TDPT-GT) application. Second, gaits of 47 patients with idiopathic normal pressure hydrocephalus (iNPH) and 92 healthy elderly individuals in the Takahata cohort were assessed with the TDPT-GT. Two-dimensional relative coordinates were calculated from the three-dimensional coordinates by projecting the sagittal, coronal, and axial planes. Indices of the two-dimensional relative coordinates associated with a pathological gait were comprehensively explored. The candidate indices for the shuffling gait were the angle range of the hip joint < 30° and relative vertical amplitude of the heel < 0.1 on the sagittal projection plane. For the short-stepped gait, the angle range of the knee joint < 45° on the sagittal projection plane was a candidate index. The candidate index for the wide-based gait was the leg outward shift > 0.1 on the axial projection plane. In conclusion, the two-dimensional coordinates on the body axis projection planes calculated from the 3D relative coordinates estimated by the TDPT-GT application enabled the quantification of pathological gait features.

Fully endoscopic occipital transtentorial approach for pineal region tumors.

PURPOSE: Aggressive surgical resection for pineal region tumors, which is a mainstay of management in almost all cases, remains technically challenging because these tumors are located at the geometric center of the brain and surrounded by critical neurovascular structures. Therefore, any refinement in the surgical procedure is desirable. We have recently introduced an endoscope to the occipital transtentorial approach (OTA), which has been one of the most common procedures for reaching the pineal region, to overcome some of the disadvantages of the procedure, including the necessity of a relatively large skin incision and bone opening, the difficulty in orientation due to the obliqueness of the approach, the possibility of retraction injury on the occipital lobe and the corpus callosum, and blind spots at the ipsilateral wall and the roof of the third ventricle. METHODS: We performed endoscopic OTA with corresponding advantages, including less invasiveness by virtue of a small entrance limiting the retraction of the occipital lobe, the elimination of blind spots, and the facilitation of fine manipulation based on the bright endoscopic view even at substantial depth, which is panoramic and can be magnified as needed. This procedure was substantially different from a conventional microscopic OTA, though both use a similar corridor. To maximize maneuverability within the limited space in endoscopic OTA, it was necessary to thoroughly understand each step of the procedure, as well as optimal sequence in the procedure. RESULTS AND CONCLUSION: We found endoscopic OTA to be a promising technique for resectioning pineal region tumors, with the potential for extensive and routine application for surgeons familiar with endoscopic surgery.

DNA methylation array analysis for diffuse leptomeningeal glioneuronal tumor with conspicuous hypothalamic mass. A case report.

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare glioneuronal neoplasm newly included in the 2016 World Health Organization Classification of Tumors of the Central Nervous System. Owing to the wide spectrum of its histopathological and radiological features, accurate diagnosis can be challenging. Recently, molecular testing including DNA methylation array has been introduced with the possibility of improving diagnostic accuracy and contributing to the subtyping especially for brain tumors with ambiguous histology. Two molecularly distinct subtypes of DLGNT have been reported: methylation class-1 (MC-1) with an indolent clinical course and MC-2, the latter aggressive. Herein, we report a case of a 14-year-old girl with a conspicuous hypothalamic mass lesion and diffuse leptomeningeal enhancement on magnetic resonance imaging. Biopsy specimens obtained from the hypothalamic lesion endoscopically were mainly composed of oligodendrocyte-like cells. However, it was difficult to make a definite diagnosis from these non-specific histological findings. Thus, DNA methylation array analysis was performed additionally by using formalin-fixed, paraffin-embedded tissue, resulting in a diagnosis of "MC-1 subtype of DLGNT" with a high calibrated score (0.99). Consequently, she was treated conservatively, with neither progression of the tumor nor aggravation of symptoms for the next 12 months. It was concluded that DNA methylation array analysis for DLGNT, a rare glioneuronal tumor, could be a powerful tool not only for accurate diagnosis but also decision-making in selecting the best treatment.

Usefulness of T2 Relaxation Time for Quantitative Prediction of Meningioma Consistency.

BACKGROUND: Meningioma consistency is one of the most critical factors affecting the difficulty of surgery. Although many studies have attempted to predict meningioma consistency via magnetic resonance imaging findings, no definitive method has been established, because most have been based on qualitative evaluations. Therefore, the present study examined the potential of the T2 relaxation time (T2 value), a tissue-specific quantitative parameter, for assessment of meningioma consistency. METHODS: Eighteen surgically treated meningiomas in 16 patients were included in the present study. Preoperatively, the T2 values of all meningiomas were calculated pixel by pixel, and a T2 value distribution map was generated. A total of 27 tumor specimens (multiple specimens were procured if heterogeneous) were taken from these meningiomas, with each localization identified intraoperatively using image guidance. The consistency of the specimens was measured with a durometer, originally a device for measuring the hardness of material such as elastic rubber, and their water content was subsequently measured using wet and dry measurements. RESULTS: A significant correlation was found between the T2 values of the matched locations identified by image guidance intraoperatively and the consistency measured using the durometer (r = -0.722; P < 0.01) and the water content (r = 0.621; P = 0.01). In addition, the water content correlated significantly with the durometer consistency (r = -0.677; P < 0.01). CONCLUSIONS: The T2 values could be a reliable quantitative predictor of meningioma consistency, and the T2 value distribution map, which elucidated the internal structure of the tumor in detail, could provide helpful information for surgical resection.

Endoscopic High Occipital Interhemispheric Transtentorial Approach for Lesions in the Anterosuperior Cerebellum, Upper Fourth Ventricle, and Upper Dorsal Brain Stem.

BACKGROUND: The occipital transtentorial route is considered the most suitable for surgical treatment of lesions arising from the anterosuperior cerebellum, upper fourth ventricle, and upper dorsal brain stem. Therefore, this study examined the feasibility and effectiveness of the endoscopic high occipital interhemispheric transtentorial approach (EHOTA) for lesions in these areas, in achieving results comparable to the endoscopic occipital interhemispheric transtentorial approach (EOTA). EOTA has recently been reported to be an effective procedure for pineal region tumors, having several advantages that include minimal invasiveness with a small entrance limiting the retraction of the occipital lobe, the elimination of blind spots, and the facilitation of fine manipulation due to the bright, magnified panoramic view. METHODS: By using 30 clinical datasets of venous-phase head computed tomography angiogram, measurements on images were performed and differences between EOTA and EHOTA were identified. In addition, the feasibility of EHOTA was verified with 5 cadaver heads. RESULTS: Although the operative field via EHOTA was considered significantly deeper and less maneuverable than with the procedure via EOTA, beneficial angles for manipulation in the superior cerebellum and the fourth ventricle were obtained in EHOTA, on account of their becoming more obtuse. Using EHOTA, it was possible to reach those regions and effectively manipulate all 10 sides of the 5 cadaveric heads, as well as a case with anterosuperior cerebellar cavernous angioma. CONCLUSIONS: EHOTA, which has the same advantages as EOTA, could prove to be an efficacious procedure for lesions in the anterosuperior cerebellum, upper fourth ventricle, and upper dorsal brain stem.

Dosing interval adjustment of denosumab for the treatment of giant cell tumor of the sphenoid bone: A case report.

BACKGROUND: In the treatment of giant cell tumor of bone (GCTB), the efficacy and safety of denosumab, a receptor activator nuclear factor κ-B ligand inhibitor, has previously been demonstrated, especially for unresectable tumors. One of the current issues in denosumab treatment for unresectable GCTB is whether it can be discontinued, or whether the dosage or the dosing interval can safely be adjusted, if discontinuation is not possible, to avoid the occurrence of side effects. CASE DESCRIPTION: A 15-year-old boy with diplopia was referred to our hospital after a space-occupying lesion in the sphenoid bone was found on head CT. Partial removal of the tumor was performed through an endoscopic endonasal approach, and pathological diagnosis was confirmed as GCTB. Thereafter, the patient received 120 mg subcutaneous injections of denosumab every 28 days for the first 2 years. Since bone formation was induced and sustained along with tumor reduction, the dosing interval was gradually extended, with 4 monthly dosing for the next 1 year, followed by 6 monthly dosing for the succeeding 2 years. With the extension of the dosing interval, the ossified tumor has regrown slightly, but within an acceptable range. CONCLUSION: Discontinuation of denosumab treatment for unresectable GCTB was not thought to be possible for the current case due to the nature of the drug, as reported in the literature. Extending the dosing interval up to 6 monthly, as could be done safely in the current case, can be considered a useful and appropriate measure.

Exclusive Endoscopic Occipital Transtentorial Approach for Pineal Region Tumors.

OBJECTIVE: Removal of pineal region tumors, which are deeply placed and encircled by intricate neurovascular structures, is challenging to neurosurgeons. The aim of this study was to present our experience with the exclusive endoscopic occipital transtentorial approach (EEOTA) used for removal of pineal region tumors. METHODS: A retrospective review was performed of patients who underwent surgery using the EEOTA to remove pineal region tumors from May 2016 to August 2018. The details of the EEOTA procedure were confirmed. RESULTS: Five patients underwent surgery via the EEOTA for treatment of pineal region tumors. In all cases, it was possible to perform the EEOTA less invasively through a keyhole craniotomy approximately 2.0-2.5 cm in size. The EEOTA produced an excellent view and provided natural and automatic orientation. There was essentially no blind spot in this procedure, even for the floor or ipsilateral wall of the third ventricle. Gross total resection was achieved in 4 cases. In the patient with atypical teratoid rhabdoid tumor, we abandoned gross total resection because of a hardened adhesion to the tectum and the great cerebral vein and its tributaries. Two patients presented with transient upper gaze palsy immediately after surgery but experienced complete recovery during the follow-up period. CONCLUSIONS: The EEOTA is a very promising technique for removal of pineal region tumors and has the potential for extensive and routine application for surgeons familiar with endoscopic surgery.

Urgent Optic Nerve Decompression via an Endoscopic Endonasal Transsphenoidal Approach for Craniopharyngioma in a 12-Month-Old Infant: A Case Report.

Craniopharyngiomas are benign tumors and account for approximately 5.6-13% of all intracranial tumors in children. Diagnosis of pediatric craniopharyngioma is often delayed until the tumor becomes relatively large and manifests severe visual and/or endocrine disturbance. Endoscopic endonasal approaches have recently been introduced to surgery for craniopharyngioma. These techniques, however, have rarely been utilized in patients affected with craniopharyngioma as young as 1 year old. This report documents a 12-month-old male infant with sellar craniopharyngioma who presented with acute total vision loss. To increase the chances of visual recovery, an endoscopic endonasal optic nerve decompression was performed as an urgent procedure. After decompression, which resulted in improvement of his visual disturbance, gross total resection of the tumor was undertaken through an anterior interhemispheric approach at a later date. Tumor mass reduction through an endoscopic endonasal transsphenoidal approach followed by secondary radical total resection under craniotomy was considered to be useful in cases such as this when urgent optic nerve decompression is required.