Clinical significance of cerebral microbleeds in patients with germinoma who underwent long-term follow-up.

PURPOSE: This study identified the factors affecting cerebral microbleed (CMBs) development. Moreover, their effects on intelligence and memory and association with stroke in patients with germinoma who had long-term follow-up were evaluated. METHODS: This study included 64 patients with germinoma who were histologically and clinically diagnosed with and treated for germinoma. These patients were evaluated cross-sectionally, with a focus on CMBs on susceptibility-weighted magnetic resonance imaging (SWI), brain atrophy assessed through volumetric analysis, and intelligence and memory. RESULTS: The follow-up period was from 32 to 412 (median: 175.5) months. In total, 43 (67%) patients had 509 CMBs and 21 did not have CMBs. Moderate correlations were observed between the number of CMBs and time from initial treatments and recurrence was found to be a risk factor for CMB development. Increased temporal CMBs had a marginal effect on the processing speed and visual memory, whereas brain atrophy had a statistically significant effect on verbal, visual, and general memory and a marginal effect on processing speed. Before SWI acquisition and during the follow-up periods, eight strokes occurred in four patients. All of these patients had ≥ 15 CMBs on SWI before stroke onset. Meanwhile, 33 patients with < 14 CMBs or 21 patients without CMBs did not experience stroke. CONCLUSION: Patients with a longer time from treatment initiation had a higher number of CMBs, and recurrence was a significant risk factor for CMB development. Furthermore, brain atrophy had a stronger effect on memory than CMBs. Increased CMBs predict the stroke onset.

Clinical and molecular features of patients with IDH1 wild-type primary glioblastoma presenting unexpected short-term survival after gross total resection.

BACKGROUND: This study investigated the factors influencing short-term survivors (STS) after gross total resection (GTR) in patients with IDH1 wild-type primary glioblastoma. METHODS: We analyzed five independent cohorts who underwent GTR, including 83 patients from Kitasato University (K-cohort), and four validation cohorts of 148 patients from co-investigators (V-cohort), 66 patients from the Kansai Molecular Diagnosis Network for the Central Nervous System tumors, 109 patients from the Cancer Genome Atlas, and 40 patients from the Glioma Longitudinal AnalySiS. The study defined STS as those who had an overall survival ≤ 12 months after GTR with subsequent radiation therapy, and concurrent and adjuvant temozolomide (TMZ). RESULTS: The study included 446 patients with glioblastoma. All cohorts experienced unexpected STS after GTR, with a range of 15.0-23.9% of the cases. Molecular profiling revealed no significant difference in major genetic alterations between the STS and non-STS groups, including MGMT, TERT, EGFR, PTEN, and CDKN2A. Clinically, the STS group had a higher incidence of non-local recurrence early in their treatment course, with 60.0% of non-local recurrence in the K-cohort and 43.5% in the V-cohort. CONCLUSIONS: The study revealed that unexpected STS after GTR in patients with glioblastoma is not uncommon and such tumors tend to present early non-local recurrence. Interestingly, we did not find any significant genetic alterations in the STS group, indicating that such major alterations are characteristics of GB rather than being reliable predictors for recurrence patterns or development of unexpected STS.

Super-selective injection of propofol into the intracranial arteries enables Patient's self-evaluation of expected neurological deficit.

INTRODUCTION: It is hard to realize the extent of the expected postoperative neurological deficit for patients themselves. The provision of appropriate information can contribute not only to examining surgical indications but also to filling the gap between patient and expert expectations. We hypothesized that propofol infusion into the intracranial arteries (ssWada) could induce focal neurological symptoms with preserved wakefulness, enabling the patients to evaluate the postsurgical risk subjectively. METHODS: Presurgical evaluation using ssWada was performed in 28 patients with drug-resistant epilepsy. Based on anatomical knowledge, propofol was super-selectively infused into the intracranial arteries including the M1, M2, and M3 segments of the middle cerebral artery (MCA), A2 segment of the anterior cerebral artery, and P2 segment of the posterior cerebral artery to evaluate the neurological and cognitive symptoms. We retrospectively analyzed a total of 107 infusion trials, including their target vessels, and elicited symptoms of motor weakness, sensory disturbance, language, unilateral hemispatial neglect (UHN), and hemianopsia. We evaluated preserved wakefulness which enabled subjective evaluations of the symptoms and comparison of the subjective experience to the objective findings, besides adverse effects during the procedure. RESULTS: Preserved wakefulness was found in 97.2% of all trials. Changes in neurological symptoms were positively evaluated for motor weakness in 51.4%, sensory disturbance in 5.6%, language in 48.6%, UHN in 22.4%, and hemianopsia in 32.7%. Six trials elicited seizures. Multivariate analysis showed significant correlations between symptom and infusion site of language and left side, language and MCA branches, motor weakness and A2 or M2 superior division, and hemianopsia and P2. Transient adverse effect was observed in 8 cases with 12 infusion trials (11.2 %). CONCLUSION: The ssWada could elicit focal neurological symptoms with preserved wakefulness. The methodology enables specific evaluation of risk for cortical resection and subjective evaluation of the expected outcome by the patients.

Distant recurrence in the cerebellar dentate nucleus through the dentato-rubro-thalamo-cortical pathway in supratentorial glioma cases.

BACKGROUND: Distant recurrence can occur by infiltration along white matter tracts or dissemination through the cerebrospinal fluid (CSF). This study aimed to clarify the clinical features and mechanisms of recurrence in the dentate nucleus (DN) in patients with supratentorial gliomas. Based on the review of our patients, we verified the hypothesis that distant DN recurrence from a supratentorial lesion occurs through the dentato-rubro-thalamo-cortical (DRTC) pathway. METHODS: A total of 380 patients with supratentorial astrocytoma, isocitrate dehydrogenase (IDH)-mutant (astrocytoma), oligodendroglioma, IDH mutant and 1p/19q-codeleted (oligodendroglioma), glioblastoma, IDH-wild type (GB), and thalamic diffuse midline glioma, H3 K27-altered (DMG), who underwent tumor resection at our department from 2009 to 2022 were included in this study. Recurrence patterns were reviewed. Additionally, clinical features and magnetic resonance imaging findings before treatment, at the appearance of an abnormal signal, and at further progression due to delayed diagnosis or after salvage treatment of cases with recurrence in the DN were reviewed. RESULTS: Of the 380 patients, 8 (2.1%) had first recurrence in the DN, 3 were asymptomatic when abnormal signals appeared, and 5 were diagnosed within one month after the onset of symptoms. Recurrence in the DN developed in 8 (7.4%) of 108 cases of astrocytoma, GB, or DMG at the frontal lobe or thalamus, whereas no other histological types or sites showed recurrence in the DN. At the time of the appearance of abnormal signals, a diffuse lesion developed at the hilus of the DN. The patterns of further progression showed that the lesions extended to the superior cerebellar peduncle, tectum, tegmentum, red nucleus, thalamus, and internal capsule along the DRTC pathway. CONCLUSION: Distant recurrence along the DRTC pathway is not rare in astrocytomas, GB, or DMG at the frontal lobe or thalamus. Recurrence in the DN developed as a result of the infiltration of tumor cells through the DRTC pathway, not dissemination through the CSF.

Distinguishing IDH mutation status in gliomas using FTIR-ATR spectra of peripheral blood plasma indicating clear traces of protein amyloid aggregation.

BACKGROUND: Glioma is a primary brain tumor and the assessment of its molecular profile in a minimally invasive manner is important in determining treatment strategies. Among the molecular abnormalities of gliomas, mutations in the isocitrate dehydrogenase (IDH) gene are strong predictors of treatment sensitivity and prognosis. In this study, we attempted to non-invasively diagnose glioma development and the presence of IDH mutations using multivariate analysis of the plasma mid-infrared absorption spectra for a comprehensive and sensitive view of changes in blood components associated with the disease and genetic mutations. These component changes are discussed in terms of absorption wavenumbers that contribute to differentiation. METHODS: Plasma samples were collected at our institutes from 84 patients with glioma (13 oligodendrogliomas, 17 IDH-mutant astrocytoma, 7 IDH wild-type diffuse glioma, and 47 glioblastomas) before treatment initiation and 72 healthy participants. FTIR-ATR spectra were obtained for each plasma sample, and PLS discriminant analysis was performed using the absorbance of each wavenumber in the fingerprint region of biomolecules as the explanatory variable. This data was used to distinguish patients with glioma from healthy participants and diagnose the presence of IDH mutations. RESULTS: The derived classification algorithm distinguished the patients with glioma from healthy participants with 83% accuracy (area under the curve (AUC) in receiver operating characteristic (ROC) = 0.908) and diagnosed the presence of IDH mutation with 75% accuracy (AUC = 0.752 in ROC) in cross-validation using 30% of the total test data. The characteristic changes in the absorption spectra suggest an increase in the ratio of ß-sheet structures in the conformational composition of blood proteins of patients with glioma. Furthermore, these changes were more pronounced in patients with IDH-mutant gliomas. CONCLUSIONS: The plasma infrared absorption spectra could be used to diagnose gliomas and the presence of IDH mutations in gliomas with a high degree of accuracy. The spectral shape of the protein absorption band showed that the ratio of ß-sheet structures in blood proteins was significantly higher in patients with glioma than in healthy participants, and protein aggregation was a distinct feature in patients with glioma with IDH mutations.

Selenoprotein P expression in glioblastoma as a regulator of ferroptosis sensitivity: preservation of GPX4 via the cycling-selenium storage.

Glioblastoma (GBM) is one of the most aggressive and deadly brain tumors; however, its current therapeutic strategies are limited. Selenoprotein P (SeP; SELENOP, encoded by the SELENOP gene) is a unique selenium-containing protein that exhibits high expression levels in astroglia. SeP is thought to be associated with ferroptosis sensitivity through the induction of glutathione peroxidase 4 (GPX4) via selenium supplementation. In this study, to elucidate the role of SeP in GBM, we analyzed its expression in GBM patients and found that SeP expression levels were significantly higher when compared to healthy subjects. Knock down of SeP in cultured GBM cells resulted in a decrease in GPX1 and GPX4 protein levels. Under the same conditions, cell death caused by RSL3, a ferroptosis inducer, was enhanced, however this enhancement was canceled by supplementation of selenite. These results indicate that SeP expression contributes to preserving GPX and selenium levels in an autocrine/paracrine manner, i.e., SeP regulates a dynamic cycling-selenium storage system in GBM. We also confirmed the role of SeP expression in ferroptosis sensitivity using patient-derived primary GBM cells. These findings indicate that expression of SeP in GBM can be a significant therapeutic target to overcome anticancer drug resistance.

Extracellular glutamate and GABA transients at the transition from interictal spiking to seizures.

Focal epilepsy is associated with intermittent brief population discharges (interictal spikes), which resemble sentinel spikes that often occur at the onset of seizures. Why interictal spikes self-terminate whilst seizures persist and propagate is incompletely understood. We used fluorescent glutamate and GABA sensors in an awake rodent model of neocortical seizures to resolve the spatiotemporal evolution of both neurotransmitters in the extracellular space. Interictal spikes were accompanied by brief glutamate transients which were maximal at the initiation site and rapidly propagated centrifugally. GABA transients lasted longer than glutamate transients and were maximal ∼1.5 mm from the focus where they propagated centripetally. Prior to seizure initiation GABA transients were attenuated, whilst glutamate transients increased, consistent with a progressive failure of local inhibitory restraint. As seizures increased in frequency, there was a gradual increase in the spatial extent of spike-associated glutamate transients associated with interictal spikes. Neurotransmitter imaging thus reveals a progressive collapse of an annulus of feed-forward GABA release, allowing seizures to escape from local inhibitory restraint.

Contemplation of the Effect of Nivolumab Plus Cabosantinib Therapy on Cerebral Hemorrhage in Patients with Brain Metastasis of Renal Cell Carcinoma: A Case Report.

Although the response to combination therapy has been reported in patients with brain metastases from advanced renal cancer, treatment-related cerebral hemorrhage has not been adequately studied. The CheckMate 9ER clinical trial of nivolumab and cabozantinib excluded patients with brain metastases. Therefore, the associated treatment outcomes in these patients with brain metastases are unclear. Herein, we report a case of bleeding from brain metastases in a patient with advanced renal cancer after gamma knife combination therapy with nivolumab and cabozantinib. Fortunately, the cerebral hemorrhage of the patient was alleviated by conservative treatment. Despite treatment interruption, the metastatic lesions reduced in size, and treatment was gradually resumed. In this case study, we report the risk of cerebral hemorrhage in combination therapy for brain metastasis cases, how to manage hemorrhage cases, and their prognosis.

Visualization of the lenticulostriate arteries, long insular arteries, and long medullary arteries on intra-arterial computed tomography angiography with ultrahigh resolution in patients with glioma.

PURPOSE: The anatomical association between the lesion and the perforating arteries supplying the pyramidal tract in insulo-opercular glioma resection should be evaluated. This study reported a novel method combining the intra-arterial administration of contrast medium and ultrahigh-resolution computed tomography angiography (UHR-IA-CTA) for visualizing the lenticulostriate arteries (LSAs), long insular arteries (LIAs), and long medullary arteries (LMAs) that supply the pyramidal tract in two patients with insulo-opercular glioma. METHODS: This method was performed by introducing a catheter to the cervical segment of the internal carotid artery. The infusion rate was set at 3 mL/s for 3 s, and the delay time from injection to scanning was determined based on the time-to-peak on angiography. On 2- and 20-mm-thick UHR-IA-CTA slab images and fusion with magnetic resonance images, the anatomical associations between the perforating arteries and the tumor and pyramidal tract were evaluated. RESULTS: This novel method clearly showed the relationship between the perforators that supply the pyramidal tract and tumor. It showed that LIAs and LMAs were far from the lesion but that the proximal LSAs were involved in both cases. Based on these results, subtotal resection was achieved without complications caused by injury of perforators. CONCLUSION: UHR-IA-CTA can be used to visualize the LSAs, LIAs, and LMAs clearly and provide useful preoperative information for insulo-opercular glioma resection.

Simulation of the occipital transtentorial approach incorporating visualization of the cerebellar tentorium using three-dimensional computed tomography angiography and gadolinium-enhanced T1-weighted magnetic resonance imaging: technical note.

The occipital transtentorial approach (OTA) is one of the useful approaches to the lesions of the pineal region, dorsal brainstem, and supracerebellar region. However, a wide operative field is sometimes difficult to obtain due to the tentorial sinus and bridging veins. This study evaluated the usefulness of preoperative simulation of OTA, specifically including the cerebellar tentorium in 9 patients. All patients underwent computed tomography angiography and venography and gadolinium-enhanced three-dimensional T1-weighted magnetic resonance images (Gd-3D-T1WI). The images were fused, and the cerebellar tentorium, vessels, and tumor were manually extracted from Gd-3D-T1WI to obtain the simulation images. Visualization of the cerebellar tentorium could discriminate between bridging veins from the occipital lobe and cerebellum, and recognize the site of bridging to the tentorial sinus and variants which may interfere with the tentorial incision. Simulation of the tentorial incision was also possible based on the relationships between the tumor, tentorial sinus, bridging vein, and cerebellar tentorium. The simulation suggested that safe tentorial incision was difficult in two sides because of the crossed tentorial sinus draining the left basal vein and draining veins from the glioblastoma. The OTA was performed in eight cases, and no difficulty was experienced in the tentorial incision in all cases. The simulation findings of the bridging vein and tentorial sinus were consistent with the intraoperative findings. Preoperative simulation including the cerebellar tentorium is useful for determining the optimum and safe side and required extent of the tentorial incision necessary for tumor resection with the OTA.

Ventriculoperitoneal Shunt Failure 3-year after Shunt Surgery Caused by Migration of Detached Ventricular Catheter into the Cranium: A Case Study of Idiopathic Normal-pressure Hydrocephalus.

Idiopathic normal-pressure hydrocephalus (iNPH) is a neurological disorder that typically presents with gait disturbance, cognitive impairment, and urinary incontinence. Although most patients respond to cerebrospinal-fluid shunting, some do not react well because of shunt failure. A 77-year-old female with iNPH underwent ventriculoperitoneal shunt implantation, and her gait impairment, cognitive dysfunction, and urge urinary incontinence improved. However, 3 years after shunting (at the age of 80), her symptoms gradually recurred for 3 months and she did not respond to shunt valve adjustment. Imaging studies revealed that the ventricular catheter detached from the shunt valve and migrated into the cranium. With immediate revision of the ventriculoperitoneal shunt, her gait disturbance, cognitive dysfunction, and urinary incontinence improved. When a patient whose symptoms have been relieved by cerebrospinal-fluid shunting experiences an exacerbation, it is important to suspect shunt failure, even if many years have passed since the surgery. Identifying the position of the catheter is crucial to determine the cause of shunt failure. Prompt shunt surgery for iNPH can be beneficial, even in elderly patients.

A Case of Haemorrhagic-Onset Glioblastoma With Delayed Diagnosis.

Glioblastoma sometimes develops with acute onset due to intracerebral hemorrhage. Although it is sometimes difficult to diagnose patients with hemorrhagic-onset glioblastoma at the acute phase of intracerebral hemorrhage (ICH), the progressive enlargement of perifocal edema or the development of contrast-enhanced lesion triggers the diagnosis of glioblastoma within six months. Herein, we present a rare case of glioblastoma in which the diagnosis was delayed as long as 17 months after ICH. A 62-year-old man presented with a headache and aphasia. Computed tomography revealed ICH in the left temporal lobe. Magnetic resonance (MR) images revealed that the hematoma had a mix of isointense and surrounding hypointense lesions on T1-weighted MR images and gadolinium-enhanced lesions at the wall and the septum of the hematoma. An endoscopic evacuation of the hematoma was performed. No causative lesions were found during intraoperative and histological examinations. After seven months, abnormal signals were completely resolved on MR images, except for the small and stable enhanced lesion on three-dimensional gadolinium-enhanced T1-weighted MR imaging (3D Gd-T1WI) at the base of the hematoma, which did not change in size for seven months. However, a large gadolinium-enhanced lesion at the left temporal lobe developed 17 months after ICH. He underwent total resection of the lesion and was diagnosed with glioblastoma. He received radiation therapy and temozolomide but died of disseminated recurrence 31 months after ICH. In conclusion, this report presents a didactic case of glioblastoma in which the diagnosis of glioblastoma was delayed 17 months after ICH whereas hemorrhagic-onset glioblastoma was previously considered ruled out in cases in which six months or more have passed after ICH. In order not to overlook these cases, follow-up with 3D Gd-T1WI is essential in the case of suspected tumor-related ICH and close follow-up is recommended when the enhanced lesion does not resolve after a long period even if it does not grow.

Spontaneous Shrinkage of isocitrate dehydrogenase (IDH)-mutant astrocytoma caused by intra-tumoural cyst rupture: a case report.

BACKGROUND: T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign is a specific imaging finding of isocitrate dehydrogenase (IDH)-mutant astrocytomas. Histologically, a hypointense area on FLAIR images indicates the presence of microcysts. Here we report a case of IDH-mutant astrocytoma that shrunk spontaneously. CASE DESCRIPTION: A 26-year-old woman presented with a complaint of headache. Her magnetic resonance (MR) images revealed a lesion mass with a T2-FLAIR mismatch sign in the left frontal lobe. Subsequently, after 1 month, she was referred to our department, and we found that the lesion had unexpectedly shrunk; however, no further shrinkage was observed in the next 3 months. Furthermore, a biopsy was performed, and the results indicated a diagnosis of astrocytoma, IDH-mutant CNS WHO grade 3. Thus, she underwent subtotal resection. We found no neurological deficits in the patient, and she received 60 Gy of radiotherapy at the local site and chemotherapy with nimustine hydrochloride (ACNU), followed by the administration of ACNU every 8 weeks for 2 years. Overall, after 36 months of tumour resection, she was in good health and exhibited no recurrence. Notably, her histological and MR image findings suggested that the macroscopic cyst was formed by the fusion of microcysts, which is a characteristic feature of IDH-mutant astrocytoma with a T2-FLAIR mismatch sign, and that the tumour shrunk because of the rupture of the cyst in the Sylvian cistern. CONCLUSION: The present case report suggests that IDH-mutant astrocytoma cannot be ruled out even when the lesion shrinks spontaneously.

Salvage craniospinal irradiation for recurrent intracranial germinoma: a single institution analysis.

This study investigated the effectiveness and safety of low-dose salvage craniospinal irradiation (CSI) for recurrent germinoma. We retrospectively reviewed long-term tumor control and late adverse effects in 15 recurrent germinoma patients treated at our hospital between 1983 and 2019. Following the first recurrence of germinoma, seven were treated with 24-30 Gy of salvage CSI, three underwent non-CSI, and five were treated with only chemotherapy. CSI achieved a significantly better recurrence-free survival rate after the first recurrence compared to other strategies (100% vs 33%, p < 0.001: log-rank test). To evaluate the safety of salvage CSI, we assessed the outcomes at the final follow-up of seven patients who received salvage CSI at first recurrence and three patients who received salvage CSI at second recurrence. The median follow-up period was 220 months after initial treatment. Five patients who received 40-50 Gy of radiation therapy or underwent multiple radiation therapy before salvage CSI were classified into Group A, whereas five patients treated with platinum-based chemotherapy and 24-32 Gy of radiation therapy to the primary site, whole ventricle, or whole brain were classified into Group B. In Group A, one had endocrine dysfunction and the other had visual dysfunction. None were socially independent. Meanwhile, in Group B, no endocrine or visual dysfunction was found, and three patients were socially independent. Salvage CSI achieved excellent tumor control in recurrent germinoma and was safe in patients initially treated with low-dose radiation therapy and chemotherapy.

Delayed Recurrence of Choroid Plexus Carcinoma in the Sacral Spinal Cord 17 Years after Its Initial Presentation.

Choroid plexus carcinomas (CPCs) are rare malignant tumors of neuro-ectodermal origin, accounting for less than 1% of all intracranial tumors. The recurrence rates of CPCs are very high and typically occur in the short-term following surgery, even after gross total removal. Here we present a rare case of CPC with spinal metastasis, which occurred long after its initial presentation. A 25-year-old woman with a history of increased intracranial pressure underwent resection for a tumor of the fourth ventricle, with a histopathological diagnosis of CPC. After tumor resection, she received 30 Gy of radiation therapy to the craniospinal axis and 20 Gy to the primary site, followed by nimustine hydrochloride chemotherapy. The residual lesion completely responded to these treatments. She suffered sensory loss in the sacral region 13 years later, followed by refractory skin ulcer in the sacral region 17 years after the initial treatments. Magnetic resonance imaging at 17 years after the initial treatments showed tumor in the sacral region, which was enlarged upon follow-up after 18 months, causing incontinence and loss of urinary intention. She underwent tumor resection, with a histological diagnosis of recurrent CPC. She received salvage re-irradiation. This case shows that CPC can spread via the cerebrospinal fluid pathways and cause spinal metastasis, with relatively slow clinical course. The present case suggests that patients with CPCs may need long-term follow-up imaging of the total neural axis to identify late recurrence at both the primary site and spinal metastasis.

Successful recording of direct cortical motor-evoked potential from a pediatric patient under remimazolam anesthesia: a case report.

BACKGROUND: Intraoperative motor-evoked potential (MEP) monitoring reduces postoperative motor deficits. Propofol-based total intravenous anesthesia is the gold standard for intraoperative myogenic MEPs. Although there is no contraindication to administering propofol in adults with peanut, soy, or egg allergies, its safety in children with these allergies remains unclear. CASE PRESENTATION: A 12-year-old girl required general anesthesia under intraoperative direct cortical MEP (dc-MEP) monitoring due to supratentorial glioma. Remimazolam-based anesthesia was selected, instead of propofol, due to the patient's egg hypersensitivity. Stable myogenic MEPs were recorded throughout the surgery with remimazolam at 0.9 mg/kg/h and remifentanil at 0.35 µg/kg/min, following adjustments of stimulation intensity and titration of remimazolam infusion. Neither intraoperative memory nor motor deficits were present after surgery. CONCLUSIONS: We present a pediatric case whose dc-MEP was recorded under remimazolam anesthesia. The cardiovascular stability and avoidance of propofol infusion syndrome with remimazolam were superior to propofol.

Methodological assessment of the reduction of dissemination risk and quantification of debris dispersion during dissection with a surgical aspirator.

OBJECTIVE: We developed an actuator-driven pulsed water jet (ADPJ) device to achieve maximal lesion dissection with minimal risk of normal structural damage. Despite the unique dissection characteristics, there is a risk of dissemination of tissue dispersion; however, there is no established method to quantify the dispersion. Hence, this study aimed to assess the factors associated with dispersion and propose a simple experimental method using spectrophotometry to evaluate the degree of dispersion in a wet field. RESULTS: Methylene blue-stained brain phantom gelatin was immersed in a chamber with distilled water solution and dissected with an ADPJ. The dispersed gelatin solution was stirred and warmed to dissolve. The absorbance of the solution was measured spectrophotometrically. First, a reference standard curve was constructed to confirm the relationship between the absorbance and the amount of the dispersed gelatin. A clear proportional correlation was observed, which indicated that absorbance measurements can help evaluate the amount of dispersion. Using this method, we revealed that a high dissection force, insufficient suction, and inappropriate long distance between the nozzle tip and the target were associated with increased dispersion. This method might constitute a versatile and reliable approach to evaluate dispersion and aid in the development of surgical devices.

Optogenetic stimulus-triggered acquisition of seizure resistance.

Unlike an electrical circuit, the hardware of the brain is susceptible to change. Repeated electrical brain stimulation mimics epileptogenesis. After such "kindling" process, a moderate stimulus would become sufficient in triggering a severe seizure. Here, we report that optogenetic neuronal stimulation can also convert the rat brain to a hyperexcitable state. However, continued stimulation once again converted the brain to a state that was strongly resistant to seizure induction. Histochemical examinations showed that moderate astrocyte activation was coincident with resilience acquisition. Administration of an adenosine A1 receptor antagonist instantly reverted the brain back to a hyperexcitable state, suggesting that hyperexcitability was suppressed by adenosine. Furthermore, an increase in basal adenosine was confirmed using in vivo microdialysis. Daily neuron-to-astrocyte signaling likely prompted a homeostatic increase in the endogenous actions of adenosine. Our data suggest that a certain stimulation paradigm could convert the brain circuit resilient to epilepsy without exogenous drug administration.

Aphasic status epilepticus after glioma resection: two case reports.

Aphasic status epilepticus (ASE) is a subtype of focal nonconvulsive status epilepticus, in which language disturbance is the only objective clinical manifestation. We present two cases of patients who experienced delayed onset of temporal aphasia after the removal of glioma at the language-dominant hemisphere. In both cases, arterial spin labeling was useful for diagnosis and antiepileptic drug was effective. ASE should be considered a cause of persistent aphasia after glioma resection at or near the language area.