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The preservation of the anterior choroidal artery (AChA) is essential for avoiding neurological sequelae after mesial temporal lobe epilepsy (mTLE) surgery. The purpose of this study is to reveal the anatomical variation in which the perforating branches arise from the plexal segment of the AChA by using a modern neuroimaging modality.This study analyzed 3D rotational angiography (3DRA) images from 56 subjects. The AChA and perforating branches were visualized using slab MIP. We analyzed branching patterns, courses of the perforating arteries arising from the plexal segment of the AChA, and the anastomosis of the AChA with other cerebral arteries.The slab MIP applied to 3DRA visualized one or more perforating branches from the AChA in 92.9% of cases. The presence of perforating branches arising from the AChA plexal segment was 17.3%. Most of the branching points of plexal perforators were likely located in the operative field during hippocampal resection. The course of the AChA plexal perforators included the posterior limb of the internal capsule. Anastomosis with other cerebral arteries was visualized in 25% of the AChA with plexal perforators.3DRA slab MIP was useful for visualizing the perforating branches of the AChA. Our results showed the possibility that surgical manipulation of the choroid plexus may cause infarction in the AChA territory. We suggest that the existence of the AChA plexal perforators should be recognized to further enhance the safety of hippocampal resection for mTLE.

BACKGROUND Intracranial cystic lesions are often a trigger for epileptic seizures. However, there has never been a report of a cystic lesion lined with fallopian tube-type epithelium. OBSERVATIONS A 48-year-old female presented with a cystic lesion in the right occipital lobe, which gradually grew over 8 years. Right occipital lobe epilepsy was diagnosed based on visual aura, convulsive seizures, and electroencephalogram findings and the cyst was surgically removed. Further examination revealed the cyst was lined with ciliated cells, which had morphological and immunohistochemical features similar to those of fallopian tube epithelium. LESSONS The characteristics of the cyst did not conform to any known types of benign cystic lesion. To the authors’ knowledge, no such cyst has been reported before. The authors discuss the origins and pathogenesis of this unfamiliar cystic lesion.

Glioblastoma is a glioma characterized by highly malignant features. Numerous studies conducted on the relationship between glioblastoma and the microenvironment have indicated the significance of tumor-associated macrophages/microglia (TAMs) in glioblastoma progression. Since interleukin (IL)-1β secreted by TAMs has been suggested to promote glioblastoma growth, we attempted to elucidate the detailed mechanisms of IL-1β in glioblastoma growth in this study. A phospho-receptor tyrosine kinase array and RNA-sequencing studies indicated that IL-1β induced the activation of signal transducer and activator of transcription-3 and nuclear factor-kappa B signaling. Glioblastoma cells stimulated by IL-1β induced the production of IL-6 and CXCL8, which synergistically promoted glioblastoma growth via signal transducer and activator of transcription-3 and nuclear factor-kappa B signaling. By immunohistochemistry, IL-1β expression was seen on TAMs, especially in perinecrotic areas. These results suggest that IL-1β might be a useful target molecule for anti-glioblastoma therapy.

Objective The purpose of this study is to investigate changes in autonomic activities and systemic circulation generated by surgical manipulation or electrical stimulation to the human brain stem. Methods We constructed a system that simultaneously recorded microsurgical field videos and heart rate variability (HRV) that represent autonomic activities. In 20 brain stem surgeries recorded, HRV features and sites of surgical manipulation were analyzed in 19 hypertensive epochs, defined as the periods with transient increases in the blood pressure. We analyzed the period during electrical stimulation to the ponto-medullary junction, performed for the purpose of monitoring a cranial nerve function. Results In the hypertensive epoch, HRV analysis showed that sympathetic activity predominated over the parasympathetic activity. The hypertensive epoch was more associated with surgical manipulation of the area in the caudal pons or the rostral medulla oblongata compared to controls. During the period of electrical stimulation, there were significant increases in blood pressures and heart rates, accompanied by sympathetic overdrive. Conclusions Our results provide physiological evidence that there is an important autonomic center located adjacent to the ponto-medullary junction. Significance A large study would reveal a candidate target of neuromodulation for disorders with autonomic imbalances such as drug-resistant hypertension.

To investigate the features associated with rapid growth of vestibular schwannoma using radiomics analysis on magnetic resonance imaging (MRI) together with clinical factors.From August 2005 to February 2019, 67 patients with vestibular schwannoma underwent contrast-enhanced T1-weighted MRI at least twice as part of their diagnosis. After excluding 3 cases with an extremely short follow-up period of 15 days or less, 64 patients were finally enrolled in this study. Ninety-three texture features were extracted from the tumor image data using 3D Slicer software (http://www.slicer.org/). We determined the texture features that significantly affected maximal tumor diameter growth of more than 2 mm/year using Random Forest and Bounty. We also analyzed age and tumor size as clinical factors. We calculated the areas under the curve (AUCs) using receiver operating characteristic analysis for prediction models using texture, clinical, and mixed factors by Random Forest and 5-fold cross-validation.Two texture features, low minimum signal and high inverse difference moment normalized (Idmn), were significantly associated with rapid growth of vestibular schwannoma. The mixed model of texture features and clinical factors offered the highest AUC (0.69), followed by the pure texture (0.67), and pure clinical (0.63) models. The minimum signal was the most important variable followed by tumor size, Idmn, and age.Our radiomics analysis found that texture features were significantly associated with the rapid growth of vestibular schwannoma in contrast-enhanced T1-weighted images. The mixed model offered a higher diagnostic performance than the pure texture or clinical models.

The poor prognosis of subarachnoid hemorrhage (SAH) might be associated with sympathetic nerve activation (catecholamine surge) initiated by hypothalamic injury. As renal denervation (RD) has been shown to exert protective effects on cardiovascular dysfunction by suppressing increased central sympathetic nerve activation, we examined whether RD improved the experimental SAH prognosis in this study. Two hundred thirty-eight male Sprague-Dawley rats were divided into sham-operated and SAH-operated groups, and then each rat was further separated into Sham-operated and RD-operated groups. Bilateral RD was performed approximately 45 min after SAH induction. We examined the effect of RD on early brain injury (EBI) and delayed cerebral ischemia (DCI) as a primary endpoint, and also explored the effect on cerebral vasospasm (CVS) as a secondary endpoint. Although RD did not exert significant effects on primary endpoint, RD significantly prevented CVS and reduced SAH-induced increases in the number of phosphorylated extracellular signal-regulated kinase (ERK)-positive endothelial cells, cyclooxygenase-2 expression, and macrophage infiltration in major cerebral arteries. Moreover, RD significantly decreased the areas displaying dopamine β-hydroxylase and glial fibrillary acidic protein immunopositivity in the paraventricular nucleus of the hypothalamus and serum angiotensin II levels, all of which were increased by SAH. Although RD decreased systolic blood pressure, significant changes in cerebral blood flow were not observed compared with SAH + Sham group. Based on the findings, RD improved CVS by reducing endothelial cell damage and the effects were associated with the stabilization of central sympathetic nerve activation in a SAH model.

Background: Movement disorders are rare in brain tumors. We describe a 45-year-old woman with hemichorea, a concomitant contralateral sphenoid ridge meningioma. Case Description: The meningioma enlarged as her hemichorea worsened, and after meningioma resection, the hemichorea gradually subsided. N-isopropyl-p-[123I]-iodoamphetamine single-photon emission computed tomography performed preoperatively showed decreased regional cerebral blood flow (CBF) to the basal ganglia circuit ipsilateral to the tumor and, when repeated postoperatively, confirmed improved regional CBF. Conclusion: We propose that the enlarging sphenoid ridge meningioma had a remote effect on regional CBF and the thalamocortical motor center and that complex changes in the basal ganglia output may have caused the hemichorea.

Background Much effort is required to dissect the adhesion in the surgical trajectory in reoperation via the lateral suboccipital retrosigmoid approach. Lumbar drainage is a standard procedure in neurosurgical practice; its usefulness during reoperation has not been reported. The purpose of this study is to elucidate whether pretreatment with lumbar drainage is effective in enabling a more straightforward lateral suboccipital approach during reoperation. Methods There were 13 reoperations among 115 lateral suboccipital craniotomies performed by a single surgeon between April 2016 and March 2018 at our institution. Lumbar drainage was performed prior to reoperations when tight adhesion was anticipated by preoperative neuroimaging. We retrospectively inspected 11 reoperations in which the video recordings were available. Results After lumber drainage, the cerebellum was slack by the start of the dural incision. The total approach time, defined as the time between starting dural incision and reaching the cerebellopontine cistern, in the group with lumbar drainage (47 min. 45 sec., n = 6) was 13 min. 46 sec. shorter than that of the group without drainage (61 min. 31 sec., n = 5) (p = 0.09). The number of times hemostasis was required in the group with drainage (4 ± 1.4) was significantly lower than that of the group without drainage (7 ± 1.4) (p Conclusions Lumbar drainage assisted in a smooth and safe dissection of the surgical trajectory for the reoperation via lateral suboccipital retrosigmoid craniotomy. Our results suggest a usefulness of lumbar drainage prior to reoperation.

Deep learning-based reconstruction (DLR) has been developed to reduce image noise and increase the signal-to-noise ratio (SNR). We aimed to evaluate the efficacy of DLR for high spatial resolution (HR)-MR cisternography. This retrospective study included 35 patients who underwent HR-MR cisternography. The images were reconstructed with or without DLR. The SNRs of the CSF and pons, contrast of the CSF and pons, and sharpness of the normal-side trigeminal nerve using full width at half maximum (FWHM) were compared between the two image types. Noise quality, sharpness, artifacts, and overall image quality of these two types of images were qualitatively scored. The SNRs of the CSF and pons were significantly higher with DLR than without DLR (CSF 21.81 ± 7.60 vs. 15.33 ± 4.03, p

Improvement of visual field defects after surgical treatment for occipital lobe epilepsy is rare. Here, the authors report on a 24-year-old man with a 15-year history of refractory epilepsy that developed after he had undergone an occipital craniotomy to remove a cerebellar astrocytoma at the age of 4. His seizures started with an elementary visual aura, followed by secondary generalized tonic-clonic convulsion. Perimetry revealed left-sided incomplete hemianopia, and MRI showed an old contusion in the right occipital lobe. After evaluation with ictal video-electroencephalography, electrocorticography, and mapping of the visual cortex with subdural electrodes, the patient underwent resection of the scarred tissue, including the epileptic focus at the occipital lobe. After surgery, he became seizure free and his visual field defect improved gradually. In addition, postoperative 123I-iomazenil (IMZ) SPECT showed partly normalized IMZ uptake in the visual cortex. This case is a practical example suggesting that neurological deficits attributable to the functional deficit zone can be remedied by successful focal resection.

Objective Hemifacial spasm (HFS) is caused by arterial conflict at the root exit zone of the facial nerve. As the offending artery is pulsatile in nature, this study investigated the association of heart rate fluctuation with HFS. Methods Twenty-four preoperative patients underwent simultaneous recordings of facial electromyogram and electrocardiogram overnight. Series of R-wave to R-wave intervals (RRIs) in the electrocardiogram were analyzed across subjects in relation to HFS. The degree of heart rate fluctuation was quantified by analyzing the heart rate variability (HRV). The sleep stage was evaluated during the period of HFS. Results A 0.1 Hz fluctuation in RRIs by 5% compared to the baseline preceded a few seconds the onset of the HFS, indicating that a significant increase in the heart rate coincided with HFS. HRV analysis demonstrated that fluctuations in the heart rate were significantly enhanced during HFS. Wake or light sleep stages were more often accompanied by HFS, suggesting an association with autonomic activities. Conclusion Our findings suggest that the etiology of HFS is more than just a mechanical compression of the facial nerve and may involve changes in pulsatile frequency in offending arteries. Significance We propose the etiology of HFS from a unique standpoint.

Only few studies have investigated the effectiveness of pregabalin (PGB) treatment for trigeminal neuralgia (TN). We aimed to retrospectively analyze the effectiveness of PGB treatment in refractory TN as a salvage treatment preceding surgery. Of 61 patients with TN refractory to prior treatment with carbamazepine (CBZ), we enrolled 33 patients in our study who agreed to receive PGB before they underwent surgery. The patients were divided into effective and ineffective groups depending on the patient-reported outcome. Correlations between effectiveness and clinical characteristics such as the age, sex, disease duration, initial CBZ responsiveness, the number of patients who underwent polytherapy with PGB and CBZ, final doses of CBZ and PGB at the time of evaluation, and the etiology of the neurovascular compression were statistically analyzed. Furthermore, a linear discriminant analysis was performed to predict effectiveness. TN was improved in 16 patients (48.5%) in the PGB-treatment group but none in patients without PGB-treatment. The final dose of PGB was 166.7 mg at the mean follow-up period of 5.5 months. Our results showed that age was the only factor that significantly differed between PGB-effective and ineffective groups. A logistic regression analysis also demonstrated that among all the clinical variables considered, only older age was significantly associated with effectiveness of PGB treatment. Effectiveness was correctly predicted at a threshold value of 62.7-years-old with 69.7% reliability. We suggest that PGB is useful, even at the low-dose, as a salvage preoperative treatment for patients with refractory TN, particularly for elderly patients.

Schwannomas are the most common intradural extramedullary spinal tumors. However, they are usually solid tumors, and totally cystic changes are rare. Herein, we report a case of a 46-year-old male presenting with numbness of right limbs, right hemiplegia, and posterior neck pain for one year. MRI revealed a well-defined cystic long-segment, from C1 to C6, intradural extramedullary mass. The lesion showed hypointense on T1WI, hyperintense on T2WI, hyperintense on DWI, and it was marginally enhanced on the contrast image with Gd-DTPA. C1 laminectomy and hemi-laminectomy from C2 to C6 was performed for tumor resection. The tumor was found to be totally cystic and tensed with a jelly-like content. It was completely resected with the attachment of the C3 dorsal root. Histopathological examination confirmed it to be a schwannoma. The mechanism of cyst formation in schwannoma is considered as results of ischemic necrosis associated with tumor growth, or cystosis due to degeneration of Antoni-type B region. The long-segment, totally cystic intradural cervical schwannoma is rare, bit it should be included in the differential diagnosis of a cystic mass in the spinal region. It can be difficult to distinguish cystic spinal schwannomas from other cystic lesions like arachnoid cyst, epidermoid cyst, and neurenteric cyst. Contrast enhanced MRI is useful by enhancing the margin of the tumor.

Schwannomas are the most common intradural extramedullary spinal tumors. However, they are usually solid tumors, and totally cystic changes are rare. Herein, we report a case of a 46-year-old male presenting with numbness of right limbs, right hemiplegia, and posterior neck pain for one year. MRI revealed a well-defined cystic long-segment, from C1 to C6, intradural extramedullary mass. The lesion showed hypointense on T1WI, hyperintense on T2WI, hyperintense on DWI, and it was marginally enhanced on the contrast image with Gd-DTPA. C1 laminectomy and hemi-laminectomy from C2 to C6 was performed for tumor resection. The tumor was found to be totally cystic and tensed with a jelly-like content. It was completely resected with the attachment of the C3 dorsal root. Histopathological examination confirmed it to be a schwannoma. The mechanism of cyst formation in schwannoma is considered as results of ischemic necrosis associated with tumor growth, or cystosis due to degeneration of Antoni-type B region. The long-segment, totally cystic intradural cervical schwannoma is rare, but it should be included in the differential diagnosis of a cystic mass in the spinal region. It can be difficult to distinguish cystic spinal schwannomas from other cystic lesions like arachnoid cyst, epidermoid cyst, and neurenteric cyst. Contrast enhanced MRI is useful by enhancing the margin of the tumor.

Spontaneous, nontraumatic, superficial temporal artery (STA) aneurysms have been rarely reported. We herewith report three cases of spontaneous and true STA aneurysms. All patients, a 65-year-old male, a 76-year-old female, and a 47-year-old female, had no history of head trauma that requires medical attention. Painless, pulsatile, and slowly growing calvarial lump was the symptom leading to image studies. All the lumps were preoperatively diagnosed as STA aneurysms by magnetic resonance angiography and/or three-dimensional computed tomographic angiography. One case was accompanied by anterior communicating aneurysm. And another case was associated with two more scalp aneurysms arising from occipital artery and contralateral STA. Pathologic studies showed that all three were true aneurysms, with intact media and adventitia but without organized hematoma. Literature review showed that 8% of all STA aneurysms comprised spontaneous STA aneurysms. We found 32 cases (19 males and 13 females) of well-described spontaneous STA aneurysms including ours. Twenty-eight cases (87.5%) were true aneurysms. Seven cases (21.9%) had coexisting vascular lesions. Five (15.6%) of these seven cases were diagnosed with cerebral or abdominal aneurysm. Multiple scalp aneurysms are quite rare; only two cases including ours have been reported. It seems important to know that spontaneous STA aneurysms may coexist with other vascular lesions including intracranial aneurysm.

Whether a difference in morphology of the infratentorial space is associated with hemifacial spasm is not well understood. The aim of this study was to analyze the three-dimensional conformation of the infratentorial space and evaluate any possible contribution of morphological characteristics to the development of neurovascular compression leading to hemifacial spasm. We enrolled 25 patients with hemifacial spasm and matched them by age and sex to controls. The extent of the three-dimensional axes and the volume of the infratentorial space were measured using image analysis software for three-dimensional MRI. We evaluated the correlation between a morphological difference in the infratentorial space and changes in vascular configuration in the brain stem. We found no statistical difference in volumetric analyses. The mean aspect ratio on the coronal plane (the ratio of the Z to X extent) of the infratentorial space in patients with hemifacial spasm was significantly lower (p

A substantial number of patients with brain tumors develop recurrent seizures, known as tumor-associated epilepsy. It is important to identify specific subgroups of brain tumor patients with higher incidences of epilepsy because a meta-analysis failed to certify the effectiveness of prophylactic anti-epileptic drugs (AEDs) to abort tumor-associated epilepsy as a whole. To investigate the relationship between tumor location and incidence of epilepsy, we performed voxel-wise comparison between 3D MRI scans obtained from patients with meningioma-associated epilepsy and those from control patients using spatial normalization techniques on neuroimaging data. Variables such as age, tumor size, the degree of edema, and pathological diagnosis were also compared between the two groups. Our results showed the highest incidence of epilepsy when the tumor was located on the premotor cortex in the frontal lobe (Z-scores >2.0, Liebermeister’s quasi-exact test). The stepwise multiple regression analysis on the clinical data revealed that the tumor diameter (p

Background 123I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy is a useful tool for differentiating idiopathic Parkinson's disease (PD) from other parkinsonian syndromes, but its prognostic value in PD has not been established. The objective of this study was to clarify the correlation between cardiac MIBG uptake parameters and the outcome in PD patients subjected to the subthalamic nucleus stimulation. Method We enrolled 31 consecutive PD patients and calculated the heart-to-mediastinum ratio (H/M) and washout rate (WR) based on the activity measured at 15 min (early phase) and 3 h (delayed phase) after the intravenous injection of MIBG (111 MBq). Cardinal motor symptoms and activity of daily living (ADL) were assessed on the Unified Parkinson's Disease Rating Scale (UPDRS) and Schwab and England (S-E) ADL scale, before and 3 months after surgery. Findings Neither early nor delayed H/M correlated with any of the preoperative subscores on the UPDRS or S-E, nor with postoperative outcome. On the other hand, increased WR was a positive predictor for postoperative improvement rate on S-E in medication-off state (p=0.00003). Also, WR showed a more faint but significant correlation with preoperative levodopa responsiveness on S-E (p=0.008). Conclusion Our findings suggest that 123I-MIBG scintigraphy in combination with levodopa-responsiveness evaluation may represent a useful tool for prediction of outcomes in patients subjected to STN stimulation.

Since optimal patient selection is essential for the success of subthalamic nucleus (STN) stimulation, the identification of reliable outcome predictors is important. The purpose of this study was to identify new imaging characteristics sufficiently reliable to predict treatment results. Using preoperative magnetic resonance imaging studies of 21 Parkinson disease (PD) patients treated by STN stimulation, we performed whole brain-based analysis of voxel-based morphometry (VBM) data. Intracranial structures segmented into the gray matter fraction (GMF), white matter fraction (WMF), and cerebrospinal fluid fraction (CSFF) were subjected to univariate and multivariate analysis of the correlation between fractional volumes and postoperative improvement rates using the Unified PD Rating Scale (UPDRS). At 3 months after surgery, the WMF was significantly correlated with improvement rated on the total UPDRS (p = 0.006), UPDRS part II (activities of daily living; p = 0.008), UPDRS part III (motor; p = 0.005). In contrast, there was no significant correlation between the effect of STN stimulation and GMF or the effect of stimulation and CSFF. The WMF also showed a significant correlation with postoperative scores in the “on” drug and “on” stimulation state (total UPDRS, p = 0.027; UPDRS part II, p = 0.019; UPDRS part III, p = 0.034). Our data indicate that patients with a larger white matter volume benefited from STN stimulation whereas the volume of other brain structures was not correlated with its effect. We posit that preserved connectivity between components of the basal ganglia-thalamocortical circuit may be required for the effectiveness of electrical stimulation. VBM may represent a powerful tool to predict the response of patients with advanced PD to STN stimulation.

There have been few reports on the surgical treatment of secondary hemidystonias, most of which are due to basal ganglia stroke or trauma. We present 2 patients with hemidystonia secondary to thalamic hemorrhage whom we successfully treated with unilateral globus pallidus internus (GPi) stimulation. Case 1 is a 56-year-old man with abnormal posturing and intolerable muscle contraction pain in the left arm. Case 2 is a 73-year-old woman who developed severe abnormal posturing in the right arm and gait disturbance due to hyperextension of the right leg. The dystonic symptoms of both patients were refractory to medication. Three months after the inception of high frequency GPi stimulation, the motor scores on the Burke-Fahn-Marsden Dystonia Rating Scale were improved by 49.2% and 34.3% in Cases 1 and 2, respectively. We suggest GPi stimulation as a possible alternative to treat secondary hemidystonia.

Background. The levodopa responsiveness of motor, particularly axial symptoms is a good predictor of the effectiveness of subthalamic nucleus (STN) stimulation in patients with Parkinson’s disease (PD). However, many Japanese PD patients are intolerant of higher doses of antiparkinsonian drugs and some aspects of their axial symptoms may remain unresponsive to treatment. We retrospectively investigated the effects of bilateral STN stimulation on the axial signs unresponsive to levodopa in Japanese patients with PD. Methods. We enrolled 29 consecutive patients into this study. Six independent axial symptoms, i.e. falling, freezing, gait, standing, posture, and postural instability, were scored on the Unified Parkinson’s Disease Rating Scale (UPDRS), before and 3 months after bilateral STN stimulation and differences were statistically analysed. Findings. Postoperatively, the mean levodopa dosage was decreased by 27%. The preoperative responsiveness to antiparkinsonian drugs with respect to freezing, gait, posture, and postural instability were positively correlated with postoperative off-medication improvement (p < 0.05). For each individual axial symptom, some patients showed an excellent response to STN stimulation, despite preoperative unresponsiveness to levodopa. These selected patients were not always treated with lower doses of antiparkinsonian drugs preoperatively, but they had milder preoperative scores on the UPDRS with respect to daily activities and overall axial function. Conclusions. The axial symptoms of PD unresponsive to levodopa were ameliorated by bilateral STN stimulation in patients manifesting a milder degree of preoperative axial signs. Our findings suggest that STN stimulation exerted a definite but limited effect on levodopa-unresponsive axial features, pointing to the need to identify different target structures that control axial functions via non-dopaminergic systems.

Eagle's syndrome (ES) and glossopharyngeal neuralgia (GPN) display very similar symptoms preoperatively. The objective of this study is to determine the surgical outcome of intraoral resection of the styloid process (IRSP) for ES, and to observe preoperative findings and treatment outcome of our cases presenting shooting craniofacial pain. In total, 14 symptomatic patients who presented with typical shooting craniofacial pain, had a styloid process longer than 25 mm, and underwent surgical intervention or medication alone from 2011 to 2015 were involved. They were divided into two groups: Group I included eight patients who underwent surgery following 3 months of medication failure, and Group II included six patients who received medication alone. Preoperative physical, radiographic findings and surgical outcomes were examined. In Group I patients, six cases received IRSP and five of those six cases experienced complete relief from symptoms and were confirmed as ES. Two other cases in Group I received microvascular decompression. One showed complete relief from symptoms, and was confirmed as GPN. The other case showed recurrence 1 year postoperatively, received IRSP with complete relief from symptoms, and was confirmed as ES. In Group II, three cases experienced complete relief from symptoms with 3 months of medication alone. IRSP is an effective treatment for ES. There was no clear difference in the preoperative findings for ES and GPN, suggesting the difficulty in making a preoperative differential diagnosis between the two conditions. Close cooperation between ENT and neurosurgery surgeons is needed.

A safe and appropriate surgical approach to the medial temporal structure is a prerequisite to perform surgeries for temporal lobe epilepsy. We used in vivo morphometry to identify the standard direction for entry into the inferior horn of the lateral ventricle via the Sylvian fissure: an important initial step in performing transsylvian selective amygdalohippocampectomy. 3D magnetic resonance images obtained from 28 patients without intra-parenchymal lesions were re-oriented to demonstrate all points in the Talairach space of the brain. The limen insulae and the midpoint between the hippocampal sulcus and the innominate sulcus on the coronal slice through the posterior edge of the amygdala were defined as the start and target points, respectively. We evaluated the direction of the vector between these two points and its validity in the brain of 12 patients with temporal lobe epilepsy. The direction of the mean approach vector was 52.4° posteriorly and 16.2° inferiorly. The mean approach vector on the axial plane showed the approximate parallelism with the sphenoid ridge in individual cases. The computer simulation revealed that our average approach vector correctly entered the inferior horn of the lateral ventricle in all temporal lobe epilepsy brains. In vivo morphometry may contribute to the further development of safe and minimally-invasive neurosurgical procedures. Electronic supplementary material The online version of this article (doi:10.1186/s40064-015-1198-x) contains supplementary material, which is available to authorized users.

Epileptic olfactory auras manifesting as simple partial seizures are rare. We report a patient who presented with olfactory auras after hemorrhage from a cavernous angioma in the left mesial temporal region. His olfactory auras persisted 12years after two surgeries for a cavernous angioma. Intracranial depth electrodes revealed a very focal isolated epileptogenic zone in the amygdala. Olfactory auras were successfully treated by focus resection.

Genetic studies of neocortical area patterning are limited, because mice deficient for candidate regulatory genes die before areas emerge and have other complicating issues. To define roles for the homeodomain transcription factor EMX2, we engineered nestin-Emx2 transgenic mice that overexpress Emx2 in cortical progenitors coincident with expression of endogenous Emx2 and survive postnatally. Cortical size, lamination, thalamus, and thalamocortical pathfinding are normal in homozygous nestin-Emx2 mice. However, primary sensory and motor areas are disproportionately altered in size and shift rostrolaterally. Heterozygous transgenics have similar but smaller changes. Opposite changes are found in heterozygous Emx2 knockout mice. Fgf8 expression in the commissural plate of nestin-Emx2 mice is indistinguishable from wild-type, but Pax6 expression is downregulated in rostral cortical progenitors, suggesting that EMX2 repression of PAX6 specification of rostral identities contributes to reduced rostral areas. We conclude that EMX2 levels in cortical progenitors disproportionately specify sizes and positions of primary cortical areas.

The mammalian striatum is the largest receptive component of the basal ganglia circuit. It is involved in the control of various aspects of motor, cognitive, and emotional functions. In the telencephalon, the striatum has a unique histological property totally different from the cortical area and its ontogenesis remains largely unknown. In this review, we introduce recent advances in the understanding of neuronal cell migration, one of the most critical processes in the early phase of histogenesis that occurs in the embryonic striatum. It appears that there are three major modes of neuronal cell migration in the developmental formation of the striatum. They are (radial) outward, tangential, and inward migration, supplying the striatum with projection neurons, interneurons, and early-generated transient neurons that originate in the preplate, respectively. We challenge the classical concept that the striatum is solely derived from the restricted germinal area located in the basal telencephalon by providing evidence that striatal development requires the intermixture of different types of neurons originating from distinct regions of the telencephalon.

Mammalian neostriatum is composed of two neurochemically and neuroanatomically defined compartments, called the patches and matrix. The present study concerns a search for neurochemical molecules involved in formation of the striatal compartments. Using the monoclonal antibody CR-50, we here disclose a transient expression of the reeler gene product Reelin, which is known to play a crucial role in neuronal positioning and axon guidance during corticogenesis, in the developing striatum of rats. Furthermore, Reelin protein is differentially concentrated in the two distinct compartments showing a mosaic-like fashion in the early postnatal period: the compartments of heightened CR-50-immunolabeling correspond to so-called “dopamine islands” (i.e., developing striosomes) visualized by tyrosine hydroxylase (TH)-immunostaining. On the basis of these findings, we hypothesize that Reelin protein may play a role in developmental organization of the striatal compartments.

A cytoplasmic protein tyrosine phosphatase (PTPase) designated as striatal enriched phosphatase with a molecular weight of 46 kDa (STEP46) is highly expressed in striatal neurons with dopamine D1-receptors. To examine the hypothesis that STEP46 is involved in the neuronal functions modulated by the cyclic adenosine 3', 5'-monophosphate (cAMP)-signaling system, we introduced the complementary DNA of STEP46 into the pheochromocytoma cell line PC12, which exhibits neuronal differentiation characterized by neurite outgrowth in response to cAMP and nerve growth factor stimulation, and we established subclonal cell lines that constitutively overexpress STEP46 protein with PTPase activity. The subclones expressing STEP46 showed increased neurite outgrowth during differentiation induced by a cAMP analogue (dibutyryl cAMP). The positive regulatory role of STEP46 in the cAMP-induced neuronal differentiation of PC12 cells indicates that STEP46 may play a role in neuronal processes modulated by the cAMP-signaling cascade as a PTPase.

We investigated the neurotoxicity evoked by N-methyl-D-aspartate (NMDA) receptor stimulation in the organotypic static slice cultures of rat cerebral cortices. We also examined whether the gamma-aminobutyric acid (GABA)A receptor agonist muscimol has a protective effect on the NMDA-mediated neurotoxicity in this culture system. NMDA-mediated cytotoxicity was evaluated histologically and quantified by the measurement of lactate dehydrogenase (LDH) release into the culture medium. There was an NMDA-induced, dose-dependent leakage of LDH release and neuronal cell death, which were not attenuated by muscimol treatment. The results suggested that NMDA neurotoxicity is reproduced in the organotypic culture, and that GABA(A) receptor activation exerted no protective action against the NMDA cytotoxicity.

Deep brain stimulation (DBS) to the thalamic ventrointermediate nucleus (Vim) is a useful treatment in patients with tremor-dominant Parkinson's disease (PD). Efficacy to alleviate rigidity remains controversial. We report a 65-year-old right-handed man with persistent severe rigidity and bradykinesia on the right side despite daily administration of levodopa/carbidopa (600/60mg). His right-hand tremor was continuous at rest and present at action. His antiparkinsonian medications appeared ineffective and he reported difficulties with writing and eating. Repeated (123)I-meta-iodobenzylguanidine myocardial scintigraphy studies demonstrated a non-PD pattern. He underwent the stereotactic implantation of a DBS electrode into the left Vim. Using contacts 1 and 2 we started continuous unipolar stimulation with a pulse generator implanted in a subclavian pocket. This improved the tremor and the rigidity and bradykinesia of his right hand. Postoperative image analysis revealed the likelihood of simultaneous stimulation of the Vim and the nucleus ventralis oralis posterior. Our findings suggest thalamic stimulation as a therapeutic option for drug-resistant rigidity (and tremor) in patients with parkinsonian syndromes ineligible for DBS targeted at the globus pallidus internus or subthalamic nucleus.