Long-term outcomes of CNS WHO grade 2 oligodendroglioma in adult patients: a single-institution experience.

PURPOSE: Oligodendrogliomas (ODGs) are a subtype of diffuse lower-grade gliomas with overall survival of > 10 years. This study aims to analyze long-term outcomes and identify prognostic factors in patients with WHO grade 2 ODG. METHODS: We retrospectively reviewed 138 adult patients diagnosed with 1p/19q co-deleted ODG who underwent surgical resection or biopsy between 1994 and 2021, analyzing clinical data, treatment details, and outcomes. Progression-free survival (PFS) and overall survival (OS) were evaluated using Kaplan-Meier analysis. Univariate and multivariate Cox regression analyses were utilized to identify significant prognostic factors. RESULTS: In the gross total resection (GTR) group, 63 (45.7%) underwent observation and 5 (3.6%) received postoperative treatment; in the non-GTR group, 37 (26.8%) were observed and 33 (23.9%) received postoperative treatment. The median PFS and OS were 6.8 and 18.4 years, respectively. Between adjuvant treatment and observation, there was no significant difference in PFS or OS. However, GTR or STR with less than 10% residual tumor exhibited significantly better PFS and OS compared to PR or biopsy (p = 0.022 and 0.032, respectively). Multivariate analysis revealed that contrast enhancement on MRI was associated with worse PFS (HR = 2.36, p < 0.001) and OS (HR = 5.89, p = 0.001). And the presence of seizures at presentation was associated with improved OS (HR = 0.28, p = 0.006). CONCLUSION: This study underscores favorable long-term outcomes for patients with 1p/19q co-deleted ODG WHO grade 2. Our findings indicate that the EOR plays a crucial role as a significant prognostic factor in enhancing PFS and OS outcomes in WHO grade 2 ODG.

Surgical Strategy for Petroclival Meningioma-Related Trigeminal Neuralgia: The Role of Porus Trigeminus Opening.

OBJECTIVE: Petroclival meningiomas invade Meckel's cave through the porus trigeminus, leading to secondary trigeminal neuralgia. Microsurgery and stereotactic radiosurgery (SRS) are the typical treatment options. This study investigated symptom control, outcomes, and surgical strategies for PC meningioma-induced TN. METHODS: We retrospectively analyzed 28 TN patients with PC meningiomas who underwent microsurgical nerve decompression between January 2021 and February 2023. In all patients undergoing a transpetrosal approach, the porus trigeminus was opened to enable the removal of the entire tumor within Meckel's cave. Clinical outcomes were assessed using the Barrow Neurologic Institute (BNI) pain intensity scale. Risk factors for poor TN outcomes and poor facial numbness were analyzed. RESULTS: Among 28 patients, 21 (75%) underwent the transpetrosal approach, 5 (17.9%) underwent the retrosigmoid approach, and 2 (7.1%) underwent the Dolenc approach. Following microsurgery, 23 patients (82.1%) experienced TN relief without further medication (BNI I or II). TN recurrence occurred in 2 patients (7.1%), and 3 patients (10.7%) did not achieve TN relief. Cavernous sinus invasion was significantly correlated with poor TN outcomes (P = 0.047). A history of previous SRS (P = 0.011) and upper clivus type tumor (P = 0.018) were significantly associated with poor facial numbness. CONCLUSIONS: Microsurgical nerve decompression is effective in improving BNI scores in patients with TN associated with PC meningiomas. Considering the results of our study, the opening of the porus trigeminus can be considered as a suggested procedure in the treatment of PC meningiomas, especially in cases accompanied by TN.

Proteomic analysis predicts anti-angiogenic resistance in recurred glioblastoma.

BACKGROUND: Recurrence is common in glioblastoma multiforme (GBM) because of the infiltrative, residual cells in the tumor margin. Standard therapy for GBM consists of surgical resection followed by chemotherapy and radiotherapy, but the median survival of GBM patients remains poor (~ 1.5 years). For recurrent GBM, anti-angiogenic treatment is one of the common treatment approaches. However, current anti-angiogenic treatment modalities are not satisfactory because of the resistance to anti-angiogenic agents in some patients. Therefore, we sought to identify novel prognostic biomarkers that can predict the therapeutic response to anti-angiogenic agents in patients with recurrent glioblastoma. METHODS: We selected patients with recurrent GBM who were treated with anti-angiogenic agents and classified them into responders and non-responders to anti-angiogenic therapy. Then, we performed proteomic analysis using liquid-chromatography mass spectrometry (LC-MS) with formalin-fixed paraffin-embedded (FFPE) tissues obtained from surgical specimens. We conducted a gene-ontology (GO) analysis based on protein abundance in the responder and non-responder groups. Based on the LC-MS and GO analysis results, we identified potential predictive biomarkers for anti-angiogenic therapy and validated them in recurrent glioblastoma patients. RESULTS: In the mass spectrometry-based approach, 4957 unique proteins were quantified with high confidence across clinical parameters. Unsupervised clustering analysis highlighted distinct proteomic patterns (n = 269 proteins) between responders and non-responders. The GO term enrichment analysis revealed a cluster of genes related to immune cell-related pathways (e.g., TMEM173, FADD, CD99) in the responder group, whereas the non-responder group had a high expression of genes related to nuclear replisome (POLD) and damaged DNA binding (ERCC2). Immunohistochemistry of these biomarkers showed that the expression levels of TMEM173 and FADD were significantly associated with the overall survival and progression-free survival of patients with recurrent GBM. CONCLUSIONS: The candidate biomarkers identified in our protein analysis may be useful for predicting the clinical response to anti-angiogenic agents in patients with recurred GBM.

Clinical Features and Prognosis of Diffuse Midline Glioma: A Series of 24 Cases.

BACKGROUND: Diffuse midline glioma (DMG) which occurs in midline structures and characterized by harboring K27M mutation in genes encoding the histone 3 protein is classified as World Health Organization (WHO) grade IV regardless of histological findings and has a poor prognosis. Nevertheless, because of its relatively rare incidence compared with other high-grade gliomas, a comprehensive description encompassing clinical features and genomic profiles of DMG is still lacking. METHODS: In this study, we analyzed data of 24 patients who were diagnosed as DMG which was confirmed by surgical specimens in both pediatric and adult patients. We described the clinical outcomes of patients with DMG and their genomic profiles through a retrospective analysis of 24 patients with DMG. RESULTS: The clinical characteristics of the 24 patients with DMG were analyzed. Ten patients (41%) underwent tumor resection and 14 patients (59%) underwent tumor biopsy. The median overall survival was 10.4 months (95% confidence interval [CI], 8.4 to 12.5) and progression free survival was 3.9 months (95% CI, 2.6 to 5.2). Fifteen patients (62%) were accompanied by hydrocephalus. None of the patient, tumor, or treatment factors had any significant associated with survival. In both immunohistochemistry staining (n=24) and targeted next generation sequencing (n=15), TP53 mutation was the most common genetic mutation (25% and 46%, respectively) found in the patients except alterations in histone 3 protein. CONCLUSION: Although surgical treatment of patient with DMG does not affect the overall survival prognosis, it can help improve the patient's accompanying neurological symptoms in some limited cases. Hydrocephalus is often accompanied with DMG and treatment for hydrocephalus is often also required. Multidisciplinary therapeutic approach is needed.

Head Injury during Childbirth.

Head injuries are the most common type of birth injuries. Among them, most of the injuries is limited to the scalp. and the prognosis is good enough to be unnoticed in some cases. Intracranial injuries caused by excessive forces during delivery are rare. However, since some of them can be fatal, it is necessary to suspect it at an early stage and evaluate thoroughly if there are abnormal findings in the patient.

Intracranial solitary fibrous tumor/hemangiopericytoma: tumor reclassification and assessment of treatment outcome via the 2016 WHO classification.

PURPOSE: As per the 2016 World Health Organization (WHO) guidelines on the classification of central nervous system tumors, solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) constitute a single disease entity, known as SFT/HPC. This study provides a clinical analysis of these tumors and describes the treatment outcomes of SFT/HPCs. METHODS: This retrospective study included 76 patients with histopathologically proven SFT/HPC. Reclassification according to the 2016 WHO guideline was done for patients who were diagnosed with SFT or HPC based on the 2007 WHO classification. Recurrence-free survival (RFS) and overall survival (OS) were evaluated for all patients and subgroups. RESULTS: The median follow-up period was 77.9 months. The median RFS and OS were 126.5 and 136.8 months, respectively. The 1-, 5-, 10-, and 15-year RFS rates were 93%, 72%, 40%, and 40%, respectively. The 1-, 5-, 10- and 15-year OS rates were 97%, 89%, 54%, and 35%, respectively. In multivariable analyses, stereotactic radiosurgery (SRS; p = 0.009, hazard ratio [HR] 6.986), female sex (p = 0.023, HR 1.76), and age over 45 (p = 0.037, HR 2.74) were associated with shorter RFS. Patients who underwent SRS as initial treatment had a shorter OS than that of patients who underwent primary resection (p < 0.001, HR 12.86). CONCLUSIONS: High-grade tumors tended to have worse OS and occur extracranial metastases earlier than low-grade tumors. The median RFS was not different between grade II and III tumors. Male sex, younger age, and GTR were associated with a better RFS. A history of SRS before tumor resection was associated with a shorter RFS and OS.

Treatment Outcome of Hydrocephalus Associated with Vestibular Schwannoma.

BACKGROUND AND PURPOSE: Managing hydrocephalus in patients with vestibular schwannoma (VS) is controversial. We evaluated the clinical factors associated with hydrocephalus. METHODS: Between 2000 and 2019, 562 patients with VS were treated at our institute. We applied endoscopic third ventriculostomy (ETV), external ventricular drainage (EVD), and ventriculoperitoneal (VP) shunts to patients with hydrocephalus. The relationships of patient, tumor, and surgical variables with the hydrocephalus outcome were assessed. RESULTS: Preoperative hydrocephalus (Evans ratio ≥0.3) was present in 128 patients. Six patients who received a preresectional VP shunt were excluded after analyzing the hydrocephalus outcome. Seven of the remaining 122 patients had severe hydrocephalus (Evans ratio ≥0.4). Primary tumor resection, VP shunting, ETV, and EVD were performed in 60, 6, 57, and 5 patients, respectively. The hydrocephalus treatment failure rate was highest in the EVD group. Persistent hydrocephalus was present in five (8%) and seven (12%) patients in the primary resection and ETV groups, respectively. Multivariate analysis revealed that severe hydrocephalus, the cystic tumor, and the extent of resection (subtotal resection or partial resection) were associated with hydrocephalus treatment failure. CONCLUSIONS: Larger ventricles and a higher cystic portion are predictive of persistent hydrocephalus. We recommend attempting near-total tumor resection in patients with VS.

Atlantoaxial instability treated with free-hand C1-C2 fusion in a child with Morquio syndrome.

Mucopolysaccharidosis type IVA, also known as Morquio syndrome, is an autosomal recessive lysosomal storage disease. Skeletal dysplasia with short stature, dysplastic-hypoplastic dens (os odontoideum), ligamentous hyperlaxity, and C1-C2 instability are characteristic features. Most patients with Morquio syndrome present with compressive myelopathy at a young age as a result of a combination of C1-C2 instability and extradural soft tissue thickening; treatment generally consists of anterior decompression with occipito-cervical fusion and external orthosis. In this report, we describe the successful treatment of a young child using posterior C1-C2 fusion alone with a free-hand technique. A 3-year-old boy presented at our hospital with a 5-month history of progressive quadriparesis. A whole-body skeletal survey showed skeletal dysplasia with hypoplasia, thoracolumbar kyphosis, and atlantoaxial subluxation. Preoperative cervical imaging showed compressive myelopathy at C1-C2 and atlantoaxial subluxation. C1-C2 fixation and decompression were performed successfully. After the operation, the patient had improved strength and was able to walk independently 8 months postoperatively. Establishment of stability via C1-C2 fusion is challenging in patients with genetic disorders characterized by skeletal dysplasia because of these young patients' small bone size and deficient bone quality. In this unique case, the treatment consisted solely of C1-C2 fusion with a free-hand technique. This case report presents a new approach in the treatment of atlantoaxial instability in Morquio syndrome.

Limited Dorsal Myeloschisis: Reconsideration of its Embryological Origin.

BACKGROUND: Limited dorsal myeloschisis (LDM) is postulated to be a result of incomplete dysjunction in primary neurulation. However, clinical experience of LDM located below the first-second sacral (S1-S2) vertebral level, which is formed from secondary neurulation (S2-coccyx), suggested that LDM may not be entirely explained as an error of primary neurulation. OBJECTIVE: To elucidate the location and characteristics of LDM to investigate the possible relation of its pathoembryogenesis to secondary neurulation. METHODS: Twenty-eight patients were surgically treated for LDM from 2010 to 2015. Since the level where the LDM stalk penetrates the interspinous ligament is most clearly defined on the preoperative MRI and operative field, this level was assessed to find out whether the lesions can occur in the region of secondary neurulation. RESULTS: Eleven patients (39%) with typical morphology of the stalk had interspinous defect levels lower than S1-S2. These patients were not different from 17 patients with classic LDMs at a level above or at S1-S2. This result shows that other than the low level of the interspinous level, 11 patients had lesions that could be defined as LDMs. CONCLUSION: By elucidating the location of LDM lesions (in particular, the interspinous level), we propose that LDM may be caused by errors of secondary neurulation. The hypothesis seems more plausible due to the supportive fact that the process of separation between the cutaneous and neural ectoderm is present during secondary neurulation. Hence, incomplete disjunction of the two ectoderms during secondary neurulation may result in LDM, similar to the pathomechanism proposed during primary neurulation.

Postoperative Symptomatic Cerebral Infarction in Pediatric Moyamoya Disease: Risk Factors and Clinical Outcome.

BACKGROUND: Indirect bypass surgery is used to improve the hemodynamic status of pediatric patients with moyamoya disease (MMD). Symptomatic cerebral infarction during the early postoperative period may be the most frustrating complication. This study was conducted to investigate the factors associated with early postoperative symptomatic cerebral infarction. METHODS: Between January 2000 and February 2014, we performed 1241 indirect bypass surgeries in 659 pediatric MMD patients. Symptomatic infarction during the early postoperative period was diagnosed in 63 operations in 61 patients. RESULTS: The overall incidence of symptomatic cerebral infarction after indirect bypass surgery was 5.1%. The median age of the patients with postoperative infarction was 6 years (mean, 6.4 years; range, 1-15 years). The performance of 2 craniotomies in single operation was associated with a higher rate of cerebral infarction. Moreover, the incidence was higher in young patients (age <6 years) compared with older patients. In a matched analysis, an immediate postoperative hemoglobin level >13 g/dL was associated with decreased risk of infarction (odds ratio, 0.144; P = 0.003). Mutation of the methylenetetrahydrofolate reductase (MTHFR) gene occurred in a relatively high proportion of our infarction cohort. CONCLUSIONS: Postoperative symptomatic infarctions can occur despite a unified surgical method and formulaic perioperative management protocol. Patient-centered factors, such as young age, genetic background of MTHFR, and certain medical conditions, including hyperthyroidism, renovascular hypertension, and hemolytic uremic syndrome, as well as management-related factors, including 2 craniotomies and low immediate postoperative hemoglobin level, could be risk factors for early postoperative symptomatic cerebral infarction.

Radical excision of lumbosacral lipoma: an early experience of "followers".

BACKGROUND: Indication, timing, and method for surgical treatment of lumbosacral lipoma are controversial. Radical resection of the lumbosacral lipoma and complete reconstruction of the placode are supported in that better long-term outcome can be achieved without increasing complication rate compared with traditional surgical techniques. OBJECTIVE: We analyzed the early surgical outcomes of lumbosacral lipoma treated with the untethering and radical excision of fat. METHODS: Retrospective analysis of surgically treated 81 fresh lumbosacral lipoma cases with dorsal, transitional, and chaotic types and true lipomyelomeningocele (LMMC) was performed. Caudal and filar types were excluded. RESULTS: Complete untethering was accomplished in 98%. Radical excision of the lipoma was attempted in all cases and achieved in 83%. Postoperative neurological complication was observed in 8 cases (10%). Group of lipoma types (dorsal + transitional vs. chaotic + true LMMC) and availability of radical lipoma excision turn out to be factors related to neurological outcomes in univariate analysis (p < 0.001 and p = 0.027, respectively). Group of lipoma types, availability of radical excision, and postoperative cord/dural sac (C/D) ratio are related factors in multivariate analysis (p = 0.025, p = 0.049, and p = 0.031). CONCLUSIONS: As a follower of untethering and radical excision of fat, careful consideration is required to plan the surgery of lumbosacral lipoma on account of the "underestimated" complication rate. Type of the lipoma is the important factor determining the surgical outcome. Availability of complete radical excision and postoperative C/D ratio are the operative factors related to the neurological outcomes.

Antiepileptic Drug Withdrawal after Surgery in Children with Focal Cortical Dysplasia: Seizure Recurrence and Its Predictors.

BACKGROUND AND PURPOSE: This study investigated the seizure recurrence rate and potential predictors of seizure recurrence following antiepileptic drug (AED) withdrawal after resective epilepsy surgery in children with focal cortical dysplasia (FCD). METHODS: We retrospectively analyzed the records of 70 children and adolescents with FCD types I, II, and IIIa who underwent resective epilepsy surgery between 2004 and 2015 and were followed for at least 2 years after surgery. RESULTS: We attempted AED withdrawal in 40 patients. The median time of starting the AED reduction was 10.8 months after surgery. Of these 40 patients, 14 patients (35%) experienced seizure recurrence during AED reduction or after AED withdrawal. Half of the 14 patients who experienced recurrence regained seizure freedom after AED reintroduction and optimization. Compared with their preoperative status, the AED dose or number was decreased in 57.1% of patients, and remained unchanged in 14.3% after surgery. A multivariate analysis found that incomplete resection (p=0.004) and epileptic discharges on the postoperative EEG (p=0.025) were important predictors of seizure recurrence after AED withdrawal. Over the mean follow-up duration of 4.5 years after surgery, 34 patients (48.6% of the entire cohort) were seizure-free with and without AEDs. CONCLUSIONS: Children with incomplete resection and epileptic discharges on postoperative EEG are at a high risk of seizure recurrence after drug withdrawal. Complete resection of FCD may lead to a favorable surgical outcome and successful AED withdrawal after surgery.

Decreased MEPs during subcutaneous dissection for untethering surgery of a "true" lipomyelomeningocele: aggravated traction of the spinal cord by release of the sac from the original nest.

PURPOSE: It is well known that the preoperative enlarged sac in occult spinal dysraphism, in which the spinal cord is attached to its dome, can be associated with neurological deficits by aggravation of spinal cord traction. We experienced a similar phenomenon during the early stage of untethering surgery for "lipomyelomeningocele in a strict sense (LMMC)." CLINICAL PRESENTATION: We report a case of a 3-month-old girl with LMMC, which showed decreased motor evoked potentials (MEPs) in the lower extremities during the early stage of untethering surgery. The sac was released from the original nest by incision with separation of the overlying skin and dissection from the muscle fascia. The sac became rounder, and the spinal cord attached to the dome of the sac was further stretched. After aspiration of cerebrospinal fluid from the sac, the MEPs recovered. Postoperatively, the patient had no neurological deficits. CONCLUSIONS: Although this phenomenon rarely occurs, release of the herniated sac of LMMC from the original nest during the early stage of untethering surgery may result in neurological changes. Application of intraoperative neurophysiological monitoring helps to detect electrophysiological deterioration and can prevent neurological deficits.

A Method of Untethering by Skipping the Area of Positive Responses on Electrical Stimulation During Surgery of Lumbosacral Lipomatous Malformation: "Hopping on a Stepping Stone".

OBJECTIVE: In complex lumbosacral lipomatous malformation or retethering, "crotch" dissection, an incision on the dura or lipoma at the site lateral to the lipoma-cord fusion line saving underlying roots, is often not easy. Attempts of this dissection in complex and obscured conditions may cause damage to the spinal cord or nerve roots. A method for caudal extension of untethering while positive areas on electrical stimulation were encountered during the crotch dissection of lumbosacral lipomatous malformation is described. METHODS: After thinning out the negative-response area just caudal to the positive-response area, a small perforation is made at the negative-response area skipping the positive-response area with probing the dissection direction through the subarachnoid space by an inside-out fashion. Subsequently, the procedure is continued caudally from the perforation site. RESULTS: Safe caudal extension of untethering is possible using this method. Illustrative operative photographs are shown. CONCLUSIONS: By using this method, safe untethering can be achieved avoiding root injuries in complicated lipomas such as chaotic or retethering cases.

Congenital Dermal Sinus and Limited Dorsal Myeloschisis: "Spectrum Disorders" of Incomplete Dysjuction Between Cutaneous and Neural Ectoderms.

BACKGROUND: The existence of tethering tracts in spinal dysraphism, other than congenital dermal sinus (CDS), has been recognized and has been summated into an integrated concept of limited dorsal myeloschisis (LDM). OBJECTIVE: To elucidate the underlying embryology of LDM in relation to CDS by focusing on the pathological features of special cases of tethering tracts. METHODS: Out of 389 spinal dysraphism patients who were operated on from 2010 to 2016, 5 patients who had tethering tracts composed of both CDS and LDM (or "probable LDM" if only fibrous tissue was found) were identified. Their clinical presentation, radiological images, operative findings, and pathology were thoroughly reviewed. RESULTS: Three nonsaccular-type patients harbored stalks in which the squamous epithelial lined sinus (CDS) was found in the distal portion, and fibroneural (LDM) or fibrous (probable LDM) tissue in the proximal part. Two patients had saccular lesions, and a stalk was found inside the sac, connecting a small pit on the skin to the spinal cord. The tracts were pathologically identical to a CDS. CONCLUSION: This study reports the coexistence of CDS and LDM (or probable LDM) components. These unique cases support the hypothesis that the CDS and LDM are among a spectrum of an anomaly that is caused by failure of complete dysjunction between cutaneous and neural ectoderms. Neurosurgeons should be aware of the possibility of coexisting "CDS" components in cases suggestive of LDM. In such cases, not only untethering but also meticulous removal of the squamous epithelium is critical.

Histone deacetylase inhibitor panobinostat potentiates the anti-cancer effects of mesenchymal stem cell-based sTRAIL gene therapy against malignant glioma.

Human adipose tissue-derived mesenchymal stem cells expressing the secreted form of the tumor necrosis factor-related apoptosis-inducing ligand (hAT-MSC.sTRAIL) have demonstrated therapeutic activity against various tumors in preclinical studies. However, the limited expression of TRAIL death receptors remains a challenge. We evaluated the therapeutic efficacy of panobinostat in enhancing the sensitivity of hAT-MSC.sTRAIL-mediated apoptosis in malignant glioma. Panobinostat effectively inhibited all malignant glioma cells (IC50, 0.03-0.23 µM), enhancing the expression of DRs, but not in hAT-MSCs. Combined treatment with hAT-MSC.sTRAIL and panobinostat significantly suppressed cell viability and enhanced apoptosis. In a diffuse intrinsic pontine glioma (DIPG) mouse model, the combined treatment induced decreases in tumor volume and prolonged survival. Our study demonstrates that panobinostat enhances the expression of TRAIL DRs and potentiates the anti-cancer effects of hAT-MSC.sTRAIL.

Predictive value of intraoperative bulbocavernosus reflex during untethering surgery for post-operative voiding function.

OBJECTIVE: To evaluate the clinical significance of intraoperative bulbocavernosus reflex (BCR) during untethering surgery in predicting post-operative voiding function. METHODS: We conducted a retrospective review of pediatric patients who underwent untethering surgery with available intraoperative baseline BCR. BCR response during surgery was classified into loss or maintenance. Post-operative voiding function was determined as worsened or maintained based on history, postvoid residual urine measurement, and urodynamic study (UDS). Data regarding demographics, diagnosis, pre-operative voiding difficulty, re-untethering, syrinx, and abnormalities in electromyography were collected for analysis. RESULTS: We included 106 patients, with a mean age of 3.3 years, and 49 patients were male. BCR was lost in 15 patients during surgery and voiding function worsened in 14 patients after surgery. Lumbosacral lipoma was the most common diagnosis, and 16 patients were diagnosed with lipomyelomeningocele (LMMC). The sensitivity and specificity of intraoperative BCR for post-operative worsening of voiding function were 35.7%, and 88.5% at 6 months, respectively. The diagnosis of LMMC was statistically significant in a logistic regression analysis. The specificity of BCR at 6 months in patients with diagnosis other than LMMC was 93.4%, and intraoperative BCR was significant in a logistic regression analysis. CONCLUSIONS: Intraoperative BCR during untethering could predict bladder function 6 months post-operatively with high specificity (88.5%), particularly in cases other than LMMC (93.4%), indicating that voiding function deterioration will not occur if intraoperative BCR is preserved. SIGNIFICANCE: Intraoperative BCR during untethering surgery is a useful tool to predict post-operative voiding outcome.

Surgical Treatment of Lesional Mesial Temporal Lobe Epilepsy.

Lesional mesial temporal lobe epilepsy (mTLE) concerns a lesion other than mesial hippocampal sclerosis present in the mesial temporal lobe and causing seizures. The lesions are usually composed of focal cortical dysplasia (FCD) or are tumorous. These are good candidates for surgical treatment. Sometimes, it is difficult to distinguish between tumors and FCD and to determine the extent of required removal. 11C-methionine positron emission tomography (PET) is helpful in differentiating lesions before surgery in lesional mTLE. In 11C-methionine PET imaging, tumors show a hot uptake, whereas FCD does not. In case of tumorous conditions, the removal of only specific lesions may be considered because the seizure outcome is dependent on complete excision of the tumor. There are several ways to safely access mesial temporal structures. The transsylvian-transcisternal approach is a good way to access the mesial structures while preserving the lateral and basal temporal structures. Actual lesions associated with epileptogenesis in FCD may be larger than they appear on magnetic resonance imaging. For this reason, evaluations to locate sufficient epileptogenic foci, including invasive studies, should be completed for FCD, and epilepsy surgery should be performed according to these results. Regardless, the ultimate goal of all epilepsy surgeries is to maximize seizure control while maintaining neurological function. Therefore, a tailored approach based on the properties of the lesion is needed.

Congenital Dermal Sinus and Limited Dorsal Myeloschisis: "Spectrum Disorders" of Incomplete Dysjuction Between Cutaneous and Neural Ectoderms.

BACKGROUND: The existence of tethering tracts in spinal dysraphism, other than congenital dermal sinus (CDS), has been recognized and has been summated into an integrated concept of limited dorsal myeloschisis (LDM). OBJECTIVE: To elucidate the underlying embryology of LDM in relation to CDS by focusing on the pathological features of special cases of tethering tracts. METHODS: Out of 389 spinal dysraphism patients who were operated on from 2010 to 2016, 5 patients who had tethering tracts composed of both CDS and LDM (or "probable LDM" if only fibrous tissue was found) were identified. Their clinical presentation, radiological images, operative findings, and pathology were thoroughly reviewed. RESULTS: Three nonsaccular-type patients harbored stalks in which the squamous epithelial lined sinus (CDS) was found in the distal portion, and fibroneural (LDM) or fibrous (probable LDM) tissue in the proximal part. Two patients had saccular lesions, and a stalk was found inside the sac, connecting a small pit on the skin to the spinal cord. The tracts were pathologically identical to a CDS. CONCLUSION: This study reports the coexistence of CDS and LDM (or probable LDM) components. These unique cases support the hypothesis that the CDS and LDM are among a spectrum of an anomaly that is caused by failure of complete dysjunction between cutaneous and neural ectoderms. Neurosurgeons should be aware of the possibility of coexisting "CDS" components in cases suggestive of LDM. In such cases, not only untethering but also meticulous removal of the squamous epithelium is critical.

Benign extracerebral fluid collection complicated by subdural hematoma and fluid collection: clinical characteristics and management.

INTRODUCTION: Benign extracerebral fluid collection (bECFC) can be complicated by subdural hematoma (SDH) or subdural fluid collection (SDFC). The etiology, natural history, and management strategy for SDH/SDFC in bECFC are not fully understood. We retrospectively reviewed the cases of bECFC patients complicated with SDH/SDFC and tried (1) to confirm the fact that bECFC children are vulnerable to SDH/SDFC, (2) to investigate the clinical significance of 'trauma history' witnessed by a caregiver, and (3) to determine optimal management for them. METHOD: Among 213 bECFC patients identified from January 2000 to August 2015, 20 patients (male:female = 14:6; median age, 6.5 months; range 1-16 months) complicated by SDH/SDFC documented with brain imaging were evaluated for their clinical manifestations, radiologic features, and management outcomes. The median follow-up period was 9.5 months. They were divided into two groups (traumatic group versus non-traumatic group) according to whether objective radiologic evidence of head injury was present or not, and the two groups were analyzed for any clinical differences between them. We also evaluated the clinical significance of witnessed traumatic events by caregivers as an additional independent variable in the analysis. RESULTS: The incidence of SDH/SDFC in bECFC patients was 9.4% (20/213) in our data. In a comparative analysis, the traumatic group is more likely to have 'acute' stage SDH, whereas the non-traumatic group is more likely to have 'chronic' stage SDH. The trauma history witnessed by caregivers did not show clinical significance in the data analysis when included as an independent variable. The prognosis of SDH/SDFC in bECFC patients was favorable without surgery in most of patients regardless of whether the patient has evidence of head trauma or not. CONCLUSION: Benign ECFC is vulnerable to SDH/SDFC development. For the bECFC patients complicated by SDH/SDFC, the trauma history witnessed by a caregiver did not show any clinical significance. A 'wait and watch' strategy is sufficient for the management of SDH/SDFC in bECFC patients.