Thymic stromal lymphopoietin contributes to ozone-induced exacerbations of eosinophilic airway inflammation via granulocyte colony-stimulating factor in mice

BACKGROUND

Ozone is one of the triggers of asthma, but its impact on the pathophysiology of asthma, such as via airway inflammation and airway hyperresponsiveness (AHR), is not fully understood. Thymic stromal lymphopoietin (TSLP) is increasingly seen as a crucial molecule associated with asthma severity, such as corticosteroid resistance.

METHODS

Female BALB/c mice sensitized and challenged with house dust mite (HDM) were exposed to ozone at 2 ppm for 3 h. Airway inflammation was assessed by the presence of inflammatory cells in bronchoalveolar lavage fluid and concentrations of cytokines including TSLP in lung. Anti-TSLP antibody was administered to mice to block the signal. Survival and adhesion of bone marrow-derived eosinophils in response to granulocyte colony-stimulating factor (G-CSF) were evaluated.

RESULTS

Ozone exposure increased eosinophilic airway inflammation and AHR in mice sensitized and challenged with HDM. In addition, TSLP, but not IL-33 and IL-25, was increased in lung by ozone exposure. To confirm whether TSLP signaling is associated with airway responses to ozone, an anti-TSLP antibody was administered, and it significantly attenuated eosinophilic airway inflammation, but not AHR. Interestingly, G-CSF, but not type 2 cytokines such as IL-4, IL-5, and IL-13, was regulated by TSLP signaling associated with eosinophilic airway inflammation, and G-CSF prolonged survival and activated eosinophil adhesion.

CONCLUSIONS

The present data show that TSLP contributes to ozone-induced exacerbations of eosinophilic airway inflammation and provide greater understanding of ozone-induced severity mechanisms in the pathophysiology of asthma related to TSLP and G-CSF.

Ventral anchoring of the conus medullaris: a new surgical technique preventing the radiographic recurrence of retethering after surgery for tethered spinal cord

OBJECTIVE

Retethering is not an unusual operation for a congenital lumbosacral dysraphic spinal lesion. The present study aimed to assess a new surgical technique for preventing retethering.

SURGICAL TECHNIQUE

After untethering the spinal cord, the pia mater or scar tissue at the caudal end of the conus medullaris is anchored to the ventral dura mater loosely using 8-0 thread, and the dura mater is closed directly. This technique is called ventral anchoring.

RESULTS

Ventral anchoring was performed in 15 patients (aged 5 to 37 years old, average age: 12.1 years old) between 2014 and 2021. All but one patient showed improvement or stabilization of the preoperative symptoms. No complication directly related to the procedure was observed. Postoperative MRI demonstrated that the dorsal subarachnoid space was restored in 14 patients but was undetectable or absent in three patients on follow-up MRI. No patients have experienced a recurrence of the tethered cord syndrome during the follow-up period.

CONCLUSION

Ventral anchoring is effective for restoring the dorsal subarachnoid space after untethering the spinal cord. This preliminary study suggested that ventral anchoring has the potential to prevent the postoperative radiographic recurrence of tethered spinal cord in patients with a congenital lumbosacral dysraphic spinal lesion.

Neoadjuvant Therapy with Everolimus for Subependymal Giant Cell Astrocytoma: A Case Report

Direct surgical resection remains to be the standard treatment for tuberous sclerosis complex (TSC) with subependymal giant cell astrocytoma (SEGA). Medical therapy with everolimus (mammalian target of rapamycin inhibitor or mTOR) serves as a second-line treatment for patients with SEGA who are determined to be ineligible for surgical resection. Some recent studies have reported that neoadjuvant therapy for SEGA may be a useful, novel treatment. In this study, we herein present a case of SEGA and demonstrate the efficacy of preoperative everolimus therapy. We have also examined the utility and safety of neoadjuvant therapy for SEGA and investigated four previously reported cases of preoperative administration of mTOR inhibitors. In these cases, everolimus was administered preoperatively to shrink the tumor although the duration of treatment varied. Afterward, gross total tumor removal was conducted in all the cases. No postoperative complications were reported during the follow-up period. These findings indicate that neoadjuvant therapy with an mTOR inhibitor can be a potential treatment for SEGA. The findings of this present study also suggested that a short administration period of about 2 months may be sufficient to achieve preoperative tumor reduction.

2144. Duration of perioperative antibiotic prophylaxis in ventriculoperitoneal shunt surgery in children

Background

Placement of ventriculoperitoneal (VP) shunt is an important treatment for pediatric hydrocephalus. Although prolonged perioperative antibiotic prophylaxis has theoretically no benefit in reducing device-associated infections, duration of antibiotic prophylaxis for VP shunt placement in pediatrics is not well established. As a part of antimicrobial stewardship program (ASP), our ASP team recommended to stop perioperative antibiotic prophylaxis for sterile medical placement within 48 hours following surgery in April 2017.

Our aim of this study was to evaluate rate of VP shunt-associated infections following shunt placement between children received < 48 hours and ≧ 48 hours of perioperative antibiotic prophylaxis.

Methods

Children aged 15 years old or younger who underwent VP shunt insertion between April 2014 and November 2021 were enrolled at Tokyo Metropolitan Children's Medical Center. Children with co-existing infection at time of surgery were excluded. Rates of VP shunt-associated infections following 1 month and 6 months of post-surgical periods were compared between children who received < 48 hours and ≧ 48 hours of perioperative antibiotic prophylaxis.

Results

A total of 110 children were identified. Among them, 11 cases with VP shunt-associated meningitis and 15 cases with other infections were excluded. Girl ratio was 44%. Median age was 4.5 months old (IQR 8-40). Numbers of children with cefazolin and vancomycin-contained regimen were 83 (98.8%) and 1 (1.2%), respectively. Numbers of children who received perioperative antibiotic prophylaxis for < 48 hours and ≧ 48 hours were 43 (51.2%) and 41 (48.8%), respectively. Incidence of VP shunt-associated infections for 1 month of post-surgical period in < 48 hours and ≧ 48 hours antibiotic prophylaxis groups were 4.65% (2/43) and 12.2% (5/41), respectively. (P=0.211)　Incidence of VP shunt-associated infections for 6 months of post-surgical period in < 48 hours and ≧ 48 hours antibiotic prophylaxis groups were 11.6% (5/43) and 12.2% (5/41), respectively. (P=0.936).

Conclusion

Shorter duration of < 48 hours of perioperative antibiotic prophylaxis did not increase rates of VP shunt-associated infections among children in short and long terms.

Disclosures

All Authors: No reported disclosures.

[Ommaya Reservoir and the External Ventricular Drainage]

Childhood hydrocephalus is a highly diverse disease caused by various factors, and most surgical treatments are performed during infancy. Despite the diversity of hydrocephalus pathologies, treatment options are limited. It is difficult for pediatric neurosurgeons to select and perform appropriate surgical procedures for neonates and infants. Treatment options for hydrocephalus are broadly divided into permanent and temporary. Permanent treatments include cerebrospinal fluid shunt and endoscopic third ventriculostomy; temporary treatment entails cerebrospinal fluid drainage using lumbar puncture and intermittent cerebrospinal fluid drainage with an Ommaya reservoir, ventricular drainage, and ventriculosubgaleal shunt. This article describes in detail Ommaya reservoir placement and ventricular drainage as representative procedures for temporarily treating hydrocephalus.

Sinus pericranii associated with syntelencephaly: a case report

Background

Sinus pericranii is a rare cranial venous malformation resulting in a subcutaneous mass due to abnormal communication between intracranial and subperiosteal/interperiosteal veins. To date, to the best of our knowledge, there are no reports of sinus pericranii associated with syntelencephaly, a subtype of lobar holoprosencephaly. We herein report a case of sinus pericranii associated with syntelencephaly. This report can provide us better understanding of the etiology of sinus pericranii, the potential risks, and the treatment options for these patients.

Case presentation

A 2-year-4-month old female patient who received the diagnosis of syntelencephaly as a neonate presented with a subcutaneous mass in the parietal region. The mass was soft, nonpulsatile, 3 × 2 cm in size, and showed enlargement in the lying position. Color cranial Doppler ultrasound, head magnetic resonance imaging (MRI), and cerebral angiography revealed a dilated vessel passing through the parietal bone and forming a communication between the superior sagittal sinus and scalp veins. Based on these findings, sinus pericranii was diagnosed. The head MRI also showed coronal craniosynostosis, a tight posterior fossa. At age 2 years and 7 months, the patient underwent a transection of the sinus pericranii and the mass resolved without any complications or recurrences for more than 2.5 years to date.

Conclusion

Sinus pericranii is a rare cranial and venous malformation sometimes accompanied by brain malformations or craniosynostosis that may become more apparent as the brain and skull develop. Since this condition can be complicated by intracranial hemorrhage and sinus thrombosis, early detection is necessary to determine the treatment options. Physicians should be alert to the possibility of this condition if they observe a soft cranial mass that appears to decrease in size in the sitting position and bulge in the lying position.

Symptomatic enophthalmos due to sphenoid wing dysplasia appearing over 12 years in a patient with neurofibromatosis type 1: a case report and literature review

Sphenoid wing dysplasia (SWD) is a common orbital complication of neurofibromatosis type 1 (NF1). However, enophthalmos associated with SWD is extremely rare, and details of its natural history are unclear. We present the case of a 14-year-old boy with an early childhood diagnosis of NF1 presenting with left blepharophimosis and enophthalmos for several months. Imaging demonstrated enlargement of the left lateral SWD, progression of the posteromedial deviation of the orbital contents, and sphenoid/ethmoid sinus deformation due to left temporal lobe compression over 12 years. Two characteristic changes were revealed on imaging: enlargement of the middle cranial fossa and deformation of the sphenoid/ethmoid sinuses. The orbital contents were compressed by the intracranial pressure of the temporal lobe and were displaced posteromedially into the space created by the deformed sphenoid/ethmoid sinuses. Because orbital symptoms can gradually become apparent over years with the progression of SWD and skeletal growth, long-term follow-up of orbital symptoms is recommended in patients with NF1.

Flow diverter stents for pediatric traumatic carotid cavernous fistula: a case report and literature review

A 10-year-old, male patient with a head injury caused by a fall presented with chemosis, exophthalmos, right orbital bruit, and intracranial venous reflux, based on which posttraumatic carotid cavernous fistula (CCF) was diagnosed. Coil embolization was semi-urgently performed for the dangerous venous drainage. After the treatment, right abducens nerve palsy newly appeared. To treat the neurological symptoms and preserve the parent artery, curative endovascular treatment using a pipeline embolization device (PED) with coil embolization was performed after starting dual antiplatelet therapy (DAPT). The CCF and abducens nerve palsy finally resolved, and the internal carotid artery (ICA) was remodeled. Use of the PED with adjunctive coil embolization was effective and safe in the present case of pediatric traumatic direct CCF.

PEDT-9 A study of NovoTTF-100A to expand the regulatory indication for childhood glioblastoma through a pediatric clinical trial based on the Advanced Medical Care system

Background: Tumor-treating fields (TTF) are alternating electric fields applied continuously to the brain by attaching 2-pair arrays on the scalp. Although TTF therapy has demonstrated efficacy against supratentorial glioblastoma (GBM) in adults, its safety and efficacy in children have not been confirmed. In Japan, off-label use of medical devices is almost impossible because the national health insurance system does not cover the cost of off-label use of drugs and medical devices. Therefore, TTF therapy cannot be applied to the treatment of pediatric GBM.

[Objectives] The investigator-initiated clinical trial aims to expand regulatory approval of TTF therapy for pediatric GBM treatment based on safety and exploratory efficacy data.

Methods: Patients aging between 5 and 17 years with histopathological diagnosis of GBM (either newly diagnosed or first-recurrence), which located in the supratentorial region would be included. All the patients will receive TTF therapy for 28 days per course for up to 26 courses until the end-of-therapy criteria are met. The primary endpoint is the adverse event rate with causality. The secondary endpoints include various time-to-event measures and QoL. In total ten patients will be enrolled.

Current Status: Discussions with the Pharmaceuticals and Medical Devices Agency (PMDA) led to a tentative consensus that the accumulated data on the efficacy of NovoTTF-100A for adult GBM may be extrapolatable to pediatric GBM if the trial is able to demonstrate efficacy equivalent to that found in previous, adult studies. On the other hand, the combination of the pediatric safety data gathered in this trial and the findings of international studies, including clinical trials and post-marketing surveillance studies, may expedite approval of the device for pediatric GBM treatment. The trial started patient enrollment in April, 2021 with the supervision of the Advanced Medical Care administration system and is currently awaiting the first eligible patient.

Transependymal Edema as a Predictor of Endoscopic Third Ventriculostomy Success in Pediatric Hydrocephalus

BACKGROUND

The Endoscopic Third Ventriculostomy Success Score (ETVSS) is based on the clinical features of hydrocephalus except for radiological findings. A previous study suggested that transependymal edema (TEE) as a radiological finding may be a reliable predictor of endoscopic third ventriculostomy (ETV) success in patients of all ages. We aimed to investigate whether TEE on preoperative magnetic resonance imaging can predict ETV success in pediatric patients.

METHODS

Medical and radiological records of all pediatric patients with an initial ETV in our hospital between 2013 and 2019 were retrospectively reviewed.

RESULTS

This study included 32 patients with hydrocephalus. The median age at surgery was 10.0 years (interquartile range: 5.6-12.9 years). There were 20 patients in the high ETVSS (90-80) group and 12 patients in the moderate ETVSS (70-50) group. The median follow-up period was 29.0 months (interquartile range: 12.9-46.2 months). The ETV success rate at the final follow-up was 81%. Preoperative brain magnetic resonance imaging revealed TEE in 20 patients and third ventricle floor ballooning in 25 patients, of whom 19 (95%) and 22 (88%), respectively, achieved successful ETV. Patients with TEE had a significantly better outcome than patients without TEE (95% vs. 58%, P = 0.018). Multivariate analysis demonstrated that the presence of TEE (odds ratio 13.6, 95% confidence interval 1.3-137.5, P = 0.027) is a significant predictor of ETV success.

CONCLUSIONS

In our cohort with a high or moderate ETVSS, the ETV success rate in patients with TEE was significantly higher than in patients without TEE, suggesting that TEE may be a useful predictor of ETV success in pediatric hydrocephalus.

Tumor-Treating Fields Therapy for Pediatric Brain Tumors

Tumor-treating fields (TTFields) are alternating electric fields applied continuously to the brain by attaching two-pair arrays on the scalp. Although TTFields therapy has demonstrated efficacy against supratentorial glioblastoma (GBM) in adults, its safety and efficacy in children have not been confirmed. Despite differences in the genetic etiology of the adult and pediatric forms of GBM, both have certain clinical behaviors in common, allowing us to test TTFields therapy in pediatric GBM. Recently, several, pediatric case-series using TTFields therapy have been published, and a few, prospective, pediatric studies are ongoing. Because GBMs are extremely rare in pediatric patients, where they comprise a wide variety of genetic subtypes, these pediatric studies are feasibility studies targeting various types of malignant brain tumor. Although they are important for confirming the safety and feasibility of TTFields therapy in the pediatric population, confirming its efficacy against each type of pediatric brain tumor, including the GBM, is difficult. Our clinical research team, therefore, planned an investigator-initiated clinical trial targeting pediatric supratentorial GBMs (as in adults) with the aim of expanding regulatory approval of TTFields therapy for pediatric GBM treatment based on safety and exploratory efficacy data in combination with the accumulated evidence on adult GBMs.

Refractory cerebral infarction in a child with an ACTA2 mutation

INTRODUCTIONS

A specific mutation in the ACTA2 gene is known to cause multisystemic smooth muscle dysfunction syndrome, which is associated with cerebrovascular diseases and various organ disorders. Cerebral infarctions resulting from severe vasculopathy can be refractory; however, there are no previous reports describing the detailed clinical course of recurrent cerebral infarctions due to an ACTA2 mutation. Herein, we report a patient with an ACTA2 mutation who experienced multiple refractory cerebral infarctions in early childhood.

PATIENT DESCRIPTION

The patient was aged 1 year and 5 months at her first episode of cerebral infarction. Arteriopathy due to an ACTA2 mutation was diagnosed based on the characteristic cerebrovascular findings and abnormal physical findings, such as bilateral dilated pupils. Bilateral encephaloduroarteriosynangiosis and encephalogaleosynangiosis were performed after the first episode. Because the cerebral infarctions recurred postoperatively, administration of cilostazol followed by bosentan was started. However, despite these treatments she experienced seven cerebral infarctions by age 2 years and 6 months.

INTERPRETATION

Cerebral infarctions in patients with a specific ACTA2 mutation can occur even in early childhood, recur frequently, and cause severe motor and cognitive impairment. Physicians should be highly aware of this disease and be ready to provide the medical and surgical interventions necessary to minimize the disabling sequelae.

Developmental changes in the occipital cranial sutures of children less than 2 years of age

PURPOSE

The occipital bone is located on the boundary between the membranous and cartilage bones and contains a wide variety of accessory sutures. In this study, we describe the age distribution of pediatric patients who are less than 2 years of age with occipital cranial sutures using a three-dimensional computed tomography (3D-CT).

METHODS

A total of 167 consecutive patients who are less than 2 years of age and underwent computed tomography for head trauma were included in this study.

RESULTS

Based on the results of this study, various types of sutures were observed among the pediatric participants. In particular, superior median fissures, mendosal sutures, other interparietal segment's accessory sutures, and interparietal sutures were noted in 21%, 35%, 9%, and 6% of the participants, respectively. Additionally, Wormian bones within the lambdoid suture were noted in 32% of the patients. The median age of children with superior median fissure and mendosal suture was 0 month. Meanwhile, superior median fissure was not observed among children older than 5 months of age. In this population, 13 patients (8%) were found to have skull fracture.

CONCLUSIONS

Knowledge of the normal cranial anatomy and developmental patterns of cranial sutures is crucial in the evaluation of questionable fractures in the occipital region. A combination of 3D-CT and axial bone window imaging is useful in differentiating normal structures from pathological changes in the cranium.

Fronto-orbital advancement in a patient with Marshall-Smith syndrome: a case report and review of the literature

OBJECTIVE

The present report aimed to document the clinical features of a case of Marshall-Smith syndrome (MSS), an extremely rare embryonic developmental disorder with associated craniosynostosis.

PATIENT AND METHOD

We presented herein a case of a 2-year-old female patient with MSS who underwent fronto-orbital advancement for multisuture craniosynostosis.

RESULTS

The patient's proptosis improved after surgery, and no further surgical intervention was required for corneal exposure. A second FOA followed by revision tarsorrhaphy further improved eye closure.

CONCLUSION

Surgical procedures to correct dysplastic features and limit neurological impairment are a worthwhile supportive treatment for improving the quality of life and general condition of patients with MSS.

GCT-62. DISSECTING INTRATUMORAL HETEROGENEITY OF CENTRAL NERVOUS SYSTEM GERM CELL TUMORS BY SINGLE-CELL RNA-SEQUENCING

BACKGROUND

Central nervous system germ cell tumor (CNSGCT) is a rare pediatric brain tumor. However, they are found at a relatively high incidence in East Asia. Germinoma is sensitive toward radiotherapy and chemotherapy; however, non-germinoma GCTs (NGGCT) often show poor response. Some cases are a mixture of germinoma and NGGCT (mixed GCT), and they sometimes change histological subtypes at recurrence. Previous report demonstrated that a germinoma and NGGCT component within the same mixed GCT tissue shared the same gene mutation, whereas the genome-wide methylation profiles were distinct from each other. The methylation profiles of germinoma was similar to the primordial germ cells (PGC) at the migration phase, supporting a model that PGC is the cell of origin for CNSGCT. However, tumor heterogeneity hinder information of the mixed bulk RNA-sequence data, causing difficulty in elucidating the mechanism of tumor development. The purpose of this study was to investigate the tumor cells subpopulations at the resolution of individual cells by single-cell RNA-seq.

RESULTS

Fresh surgical tumor tissue was immediately dissociated mechanically and enzymatically. Tumor cells are separated from CD45-labelled lymphocytes by FACS, and libraries were generated by Chromium Single cell 3’ Reagent Kit. Total of 11 tumor samples were collected and sequenced. Unsupervised Clustering showed individual clusters. One of the clusters had high expression of Oct-4, which is a marker of germinoma. The other clusters showed different subtypes of cells representing the heterogeneity of CNSGCT. Further analysis including a pseudo-time course analysis is underway to identify the lineage of tumor cell development.

Basal encephalocele: surgical strategy and functional outcomes in the Tokyo experience

OBJECTIVE

The basal encephalocele (BEC) is the rarest form of encephalocele, with an incidence of about 1/35,000 live births. The incidence of its subtype, sphenoidal BEC, is even lower at about 1/700,000 live births. The aim of this study was to propose the optimal surgical approach to repairing BEC, with special attention to the reconstruction of the skull base bone defect.

METHODS

Fourteen consecutive pediatric patients with BEC who underwent surgical repair between March 2004 and March 2020 (10 boys and 4 girls, age 25 days to 7 years, median age 4 months) were enrolled. The follow-up period of the surviving patients ranged from 53 to192 months (mean 119.8 months). The patient demographics, BEC subtypes, preoperative clinical condition, radiographic findings, surgical procedures, and postoperative course were retrospectively analyzed.

RESULTS

There were 4, 8, and 2 cases of sphenoidal BEC, sphenoethmoidal BEC, and ethmoidal BEC, respectively. The size of the bone defect was small in 3 patients, medium in 7, and large in 4 patients. All the patients with sphenoethmoidal and ethmoidal BEC showed associated congenital anomalies other than cleft palate. In total, 25 operations were performed. Two patients underwent multiple operations, whereas the remaining 9 patients received only 1 operation. The transoral transpalatal approach was the initial procedure used in all 14 patients. The transfrontobasal approach was applied as an additional procedure in 2 patients and as part of a 1-stage combined operation in 2 patients. Autograft bone alone was used for skull base reconstruction in 17 early operations. A titanium mesh/plate was used in the remaining 8 operations without any perioperative complications. All BECs were successfully repaired. Three patients died during the clinical course due to causes unrelated to their surgery. All but one of the surviving patients started growth hormone replacement therapy before school age.

CONCLUSIONS

Based on the authors' limited experience, the key to successful BEC repair involves circumferential dissection of the BEC and a firm reconstruction of the skull base bone defect with a titanium plate/mesh. The transoral transpalatal approach is a promising, reliable procedure that may be used in the initial operation. When a cleft palate is absent, transnasal endoscopic repair is recommended. The transfrontobasal approach should be reserved for cases with a huge BEC and other anomalies. Long-term prognosis is apparently favorable in survivors.

White matter abnormality in Jacobsen syndrome assessed by serial MRI

INTRODUCTION

Jacobsen syndrome (JS) is caused by a deletion at the terminus of the long arm of chromosome 11. There are few reports of JS associated with cerebral white matter abnormalities (WMA), and the etiology, pathophysiology, and time-dependent changes in WMA with JS still remain unclear.

CASE REPORT

The patient was a 2-month-old female with several morphological anomalies, including trigonocephaly, ectropion, flat nasal bridge, low-set ears, and sparse eyebrows. Chromosome analysis (G-banding karyotyping) of 46,XX,del(11)(q23.3) led to the diagnosis of JS. Head MRI performed at age 9 months indicated diffuse WMA with hyperintense signals on T2-weighted imaging. MRI at age 2.5 years demonstrated a decrease in the WMA and progressive myelination.

DISCUSSION

These findings suggested that the WMA in the present patient were due to chronic white matter edema associated with a deletion in the 11q terminal region of HEPACAM/GlialCAM, a causative gene for megalencephalic leukoencephalopathy with subcortical cysts type 2B (MLC2B). As with some of MLC2B patients, the WMA in the present patient improved over time. The present report is the first to document dramatic changes in WMA in JS visualized by serial MRI examinations from the neonatal period through early childhood.

CONCLUSION

The findings of the present study suggested that WMA in JS are due to chronic white matter edema associated with HEPACAM/GlialCAM deletion and show gradual improvement over time, as seen in some MLC2B patients.

Proton therapy for newly diagnosed pediatric diffuse intrinsic pontine glioma

INTRODUCTION

Diffuse intrinsic pontine glioma (DIPG) is a type of brain malignancy with a very poor prognosis. Although various radiation and chemotherapy protocols have been attempted, only conventional radiotherapy has yielded improvements in survival. In this study, we aimed to compare proton therapy versus conventional photon radiotherapy in terms of the outcomes of pediatric patients with DIPG.

METHODS

This retrospective review included 12 pediatric patients with newly diagnosed DIPG who received a total proton therapy dose of 54 Gy (relative biological effectiveness) in 30 fractions at the University of Tsukuba Hospital between 2011 and 2017 (proton group). We additionally reviewed the medical records of 10 patients with DIPG who previously underwent conventional photon radiotherapy at our institute (historical cohort).

RESULTS

The median progression-free survival (PFS) duration was 5 months (range 1-11 months), and the 6-, 12-, and 18-month PFS rates were 50%, 33%, and 25%, respectively. The median overall survival (OS) duration was 9 months (range 4-48 months), and the 6-, 12-, 18-, and 24-month OS rates were 66.8%, 50%, 41%, and 20%, respectively. There were no significant differences in survival between the proton and historical groups (PFS, p = 0.169 and OS, p = 0.16).

CONCLUSIONS

Proton therapy was well tolerated by the majority of patients. No severe adverse events, including radiation necrosis, were recorded. Proton therapy did not yield superior survival outcomes vs. conventional photon radiotherapy in patients with DIPG at our institution. Further research is needed to identify the factors associated with better survival in this population.

Severe Noonan syndrome phenotype associated with a germline Q71R MRAS variant: a recurrent substitution in RAS homologs in various cancers

Activation of the RAS pathway through either the activation of genes that accelerate the pathway or the suppression of genes that inhibit the pathway leads to a group of disorders collectively referred to as RASopathies. The key molecules of the RAS pathway are KRAS, HRAS, and NRAS. Mutations in these three RAS homolog genes have been shown to be associated with RASopathies. Recently, two patients with a Noonan syndrome phenotype were shown to carry mutations in the yet another RASopathy gene, MRAS (muscle RAS oncogene homolog). Here, we report a patient with a severe Noonan syndrome phenotype associated with a germline Q71R MRAS variant, which represents a recurrent substitution in RAS homologs in various cancers. The patient's dysmorphic features included relative macrocephaly, a down-slanted palpebral fissure, hypertelorism, a depressed nasal bridge, and low-set ears with thick lobes; these facial features are strongly associated with RASopathy. We confirmed that the MRAS gene represents a causative gene for RASopathy.

Surgical management of cervical spine deformity in chondrodysplasia punctata

OBJECTIVE Chondrodysplasia punctata (CDP), a rare skeletal dysplasia, can lead to cervical spine instability and deformity. However, an optimal neurosurgical intervention has yet to be established. Thus, a retrospective study was conducted to assess the efficacy of various surgical interventions for children with CDP. METHODS The authors retrospectively reviewed 9 cases of CDP in which cervical decompression with or without posterior fusion was performed between April 2007 and May 2016. Patient demographics, preoperative clinical conditions, radiographic findings, surgical procedures, and the postoperative course were analyzed in detail. RESULTS A total of 12 operations were carried out in 9 patients (8 male, 1 female) during the study period. The patients' ages at the initial surgery ranged from 2 months to 2 years. Seven of the children had CDPX1, 1 had CDPX2, and 1 had tibia-metacarpal type CDP (CDP-TM). The lesion occurred at the craniovertebral junction (CVJ) in 7 cases and involved a subaxial deformity in 2 cases. The initial surgery was C-1 laminectomy with occipitocervical fusion (OCF) followed by halo external fixation in 5 cases, OCF alone in 1 case, and C-1 laminectomy alone in 3 cases. Three children required additional surgery. In one of these cases, a staged operation was required because the patient's head was too small to attach a halo ring at the time of the initial procedure (C-1 laminectomy). In another case, OCF was performed 11 months after C-1 laminectomy because of intramedullary signal change on serial MRI, although the child remained asymptomatic. In the third case, additional posterior fusion was performed 17 months after an initial laminectomy and OCF due to newly developed cervical dislocation caudal to the original fusion. This last patient required a third operation 9 months after the second because of deep wound infection. Surgery improved the motor function of all 7 children with CDPX1, but 3 children who had already suffered respiratory failure preoperatively required continued respiratory support. At the time of this report, 7 of the 9 children were alive and in stable condition. One child died due to restrictive respiratory insufficiency, and another died in an accident unrelated to CDP. CONCLUSIONS Surgical decompression with or without fusion for CVJ and subaxial cervical lesions in infants and toddlers with CDP generally saves lives and increases the likelihood of motor function recovery. However, in this case series the patients' preoperative condition had a strong effect on postoperative respiratory function. The surgery was not straightforward, and a second operation was required in some cases. Nevertheless, the findings indicate that early surgical intervention for CDP with cervical involvement is feasible, suggesting that the role of neurosurgery should be reevaluated.

Impact of magnetic resonance imaging and urodynamic studies on the management of sacrococcygeal dimples

OBJECTIVE Sacrococcygeal dimples in neonates and infants are of uncertain pathological import. Previously they were believed to be rarely associated with intraspinal anomalies. Recent studies using MRI, however, revealed that 6%-7% of pediatric cases of sacrococcygeal dimples were associated with anatomical tethered spinal cord (TSC). Because the prevalence of tethered cord syndrome is still unclear, there is no consensus among pediatric neurosurgeons on the management of children with sacrococcygeal dimples. The authors performed an analysis of MRI and urodynamic studies to validate their management strategy for pediatric cases of sacrococcygeal dimples. METHODS A total of 103 Japanese children (49 male and 54 female, median age 4 months, range 8 days-83 months) with sacrococcygeal dimples who were referred to the Division of Pediatric Neurosurgery between 2013 and 2015 were included in this study. The lumbosacral region of all the patients was investigated using MRI. Anatomical TSC was defined as a condition in which the caudal end of the conus medullaris is lower than the inferior border of the L2-3 intervertebral disc. Patients with minor spinal anomalies (e.g., anatomical TSC, filum lipoma, thickened filum, or filar cyst) underwent further urodynamic studies to ascertain the presence of neurogenic bladder (NGB). In this study, the presence of NGB without anatomical TSC but with other minor spinal anomalies was defined as "functional TSC." The prevalence of anatomical and functional TSC was investigated. The association of the following cutaneous findings with spinal anomalies was also assessed: 1) depth of the dimple, 2) deviation of the gluteal fold, and 3) other skin abnormalities (e.g., discoloration, angioma, or abnormal hair). RESULTS The children were classified into 4 groups: Group 1, patients with anatomical TSC; Group 2, patients with functional TSC; Group 3, patients without anatomical or functional TSC but with other minor spinal anomalies; and Group 4, patients with no spinal anomaly. There were 6 patients (5.8%) in Group 1, 8 patients (7.8%) in Group 2, 10 patients (9.7%) in Group 3, and 79 patients (76.7%) in Group 4. Twenty-four patients (23.3%; Groups 1, 2, and 3) showed MRI abnormalities, including filum lipoma (14 cases), filar cysts (5 cases), thickened filum (2 cases), and anatomical TSC without other spinal anomalies (3 cases). Untethering of the spinal cord was indicated for 14 patients (13.6%; Groups 1 and 2) with anatomical and functional TSCs. Preoperative NGB was found in 12 patients and improved postoperatively in 7 (58.3%). None of the associated lumbosacral skin findings predicted the presence of underlying spinal anomalies. CONCLUSIONS The prevalence of tethered cord syndrome among children with sacrococcygeal dimples was, for the first time, revealed to be higher than previously thought. MRI and supplemental urodynamic studies may be indicated for children with sacrococcygeal dimples to identify patients with symptomatic TSC.

New classification of spinal lipomas based on embryonic stage

OBJECTIVE Spinal lipomas are generally thought to occur as a result of failed primary neurulation. However, some clinical features cannot be explained by this theory. The authors propose a novel classification of spinal lipomas based on embryonic changes seen during primary and secondary neurulation. METHODS A total of 677 patients with occult spinal dysraphism underwent 699 surgeries between August 2002 and May 2015 at the National Center for Child Health and Development and Tokyo Metropolitan Children's Medical Center. This group of patients had 378 spinal lipomas, including 119 conus spinal lipomas, 27 lipomyelomeningoceles, and 232 filum lipomas, which the authors classified into 4 types based on neural tube formation during embryonic development. Type 1 is defined as pure primary neurulation failure; Type 2 ranges from primary to secondary neurulation failure; Type 3 consists of secondary neurulation failure (early phase); and Type 4 is defined as secondary neurulation failure (late phase). The authors also review embryogenesis in secondary neurulation and analyze the clinical utility of the new classification. RESULTS There were 55 Type 1 spinal lipomas, 29 Type 2, 62 Type 3, and 232 Type 4. All filum lipomas fell into the Type 4 spinal lipoma category. Association with anorectal and/or sacral anomalies was seen in none of the Type 1 cases, 15 (52%) of Type 2, 35 (56%) of Type 3, and 31 (13%) of Type 4. Urogenital anomalies were observed in none of the Type 1 or Type 2 cases, 1 (2%) of Type 3, and 28 (12%) of Type 4. Anomaly syndromes were present in none of the Type 1 cases, 6 (21%) of Type 2, 3 (5%) of Type 3, and 16 (7%) of Type 4. Associated anomalies or anomaly syndromes were clearly observed only for Type 2-4 spinal lipomas encompassing failed secondary neurulation. Radical resection was feasible for Type 1 spinal lipomas. CONCLUSIONS Secondary neurulation of the spinal cord gives rise to the conus medullaris and filum terminale, which are often involved in spinal lipomas. Formation of spinal lipomas seems to be a continuous process overlapping primary and secondary neurulation in some cases. Association with other anomalies was higher in Type 2-4 spinal lipomas, which included failed secondary neurulation, than in Type 1 lipomas, with failed primary neurulation. On the other hand, radical resection was indicated for Type 1, but not for Type 2, spinal lipomas. The new classification of spinal lipomas based on embryonic stage has the potential for clinical use and agrees well with both clinical and surgical findings. The classification proposed here is still preliminary. Further studies and verification are necessary to establish its clinical utility.

Hyper-vascular giant cavernous malformation in a child: a case report and review

INTRODUCTION

Giant cavernous malformation (GCM) in children is a rare vascular anomaly, and its natural history is unclear. Despite their giant size, intraparenchymal GCMs are low-flow vascular malformations. Herein, we report a case of hyper-vascular intraparenchymal GCM with an AV shunt in a child.

CASE

A 3-year-old boy had had an enlarged head since infancy. Magnetic resonance (MR) images on admission showed a strikingly enhanced mass lesion, 6 cm in size. A 4-vessel CAG demonstrated a hyper-vascular mass with an AV shunt. After transarterial embolization, the patient underwent total excision of the mass. The tumor bled easily, during surgery the patient lost 400 cm³ in blood. Histopathological examination confirmed the diagnosis of cavernous hemangioma.

CONCLUSION

The differential diagnosis of intraparenchymal, strikingly-enhanced tumors with an AV shunt include hyper-vascular GCMs. Consideration of potential for bleeding during the operation is also important.

Pediatric intraventricular arachnoid cysts in the body of lateral ventricle: surgical outcome and its embryologic background

PURPOSE

The aim of this study is for the surgical treatment and outcome of the endoscopic fenestration of the arachnoid cyst located in the ventricular body to trigone in the pediatric population. Special concern was paid for the developmental origin of the intraventricular cysts estimated from the postoperative follow-up neuroimagings.

PATIENTS AND METHODS

Between July 2002 and June 2015, we performed endoscopic and partly CT/MRI navigated fenestrations of intraventricular arachnoid cysts located at the body to trigone of the lateral ventricle in ten pediatric patients aged 2 months to 5 years. Based on the long axis of the cyst, we have opted for two surgical approaches: anterior approach via burr hole at Kocher's point and posterior approach via burr hole at the posterior occipital region. Fenestration was performed based on the intraoperative findings, either ventriculocystostomy, ventriculocystoventriculostomy, or ventriculocystocisternostomy.

RESULTS

Intraventricular arachnoid cysts located in the body-trigone region showed a favorable outcome after endoscopic fenestration. All of the cysts shrank postoperatively. Follow-up neuroimagings taken between 6 and 126 months after surgery strongly suggested its relationship with the midline cisterns. Of our ten cases, eight were suggestive for originating from the velum interpositum cistern while two seemed to root from the quadrigeminal cistern.

CONCLUSION

In the present study, we found that endoscopic fenestration of intraventricular arachnoid cysts in the body to trigone is a safe procedure with a satisfactory outcome. In our limited experience, there are two anatomic backgrounds; velum interpositum cistern and quadrigeminal cistern. Differentiation can be possible by neuroimagings, especially those obtained after surgery.

Reversible diffusion weighted imaging hyperintensities during the acute phase of ischemic stroke in pediatric moyamoya disease: a case report

BACKGROUND

Moyamoya disease is one of the primary causes of pediatric ischemic stroke, especially in East Asia. Areas of high signal intensity on diffusion weighted imaging (DWI) with decreased apparent diffusion coefficient (ADC) values usually point to irreversible ischemic damage. Reversibility of these DWI hyperintensities during the acute phase of ischemic stroke in pediatric moyamoya disease has not previously been reported.

CASE REPORT

A 3-year-old girl was admitted to our emergency department due to sudden onset speech impairment and right hemiplegia. Computed tomography (CT) revealed a multilobal low-density area in the left cerebral hemisphere. The area was hyperintense on DWI with decreased ADC values. Magnetic resonance (MR) angiography revealed stenosis of the bilateral internal carotid artery bifurcations and their branches. Acute cerebral infarction due to moyamoya disease was diagnosed. MR images taken 4 days later showed resolution of most of the DWI hyperintensity areas. The initial decline in the ADC of the reversible DWI hyperintensities was less severe compared to the irreversible lesion. Within several days after onset, the patient became ambulatory although the follow-up MR fluid attenuated inversion recovery (FLAIR) images taken 2 weeks after onset revealed thinning of the corresponding cortical gyri.

CONCLUSION

These findings indicate that a wide area of DWI hyperintensity during the acute phase of ischemic stroke can be reversed by appropriate treatment in pediatric moyamoya disease. To the best of our knowledge, this is the first report of reversible DWI hyperintensities over a wide cortical area during the acute phase of ischemic stroke in pediatric moyamoya disease.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

Simple model of pH-induced protein denaturation

The pH-induced conformational changes of proteins are systematically studied in the framework of a hydrophobic-polar (HP) model, in which proteins are dramatically simplified as chains of hydrophobic (H) and polar (P) beads on a lattice. We express the electrostatic interaction, the principal driving force of pH-induced unfolding that is not included in the conventional HP model, as the repulsive energy term between P monomers. As a result of the exact enumeration of all of the 14- to 18-mers, it is found that lowest-energy states in many sequences change from single "native" conformations to multiple sets of "denatured" conformations with an increase in the electrostatic repulsion. The switching of the lowest-energy states occurs in quite a similar way to real proteins: it is almost always between two states, while in a small fraction of ≥16-mers it is between three states. We also calculate the structural fluctuations for all of the denatured states and find that the denatured states contain a broad range of incompletely unfolded conformations, similar to "molten globule" states referred to in acid or alkaline denatured real proteins. These results show that the proposed model provides a simple physical picture of pH-induced protein denaturation.

[Functional neurosurgery for spasticity]

The basic concept of neurosurgical procedures to treat spasticity is to decrease the hyperactivity of the stretch reflex. Selective peripheral neurotomy is a method to partially resect the peripheral motor nerve. The alpha motor and Ia afferent nerves are resected, but the latter is essential owing to its lasting effect in reducing spasticity. Focal spasticity in adult patients can be effectively treated using peripheral neurotomy. Functional posterior rhizotomy, mostly used to treat paraplegic spasticity in children with cerebral palsy, involves the sectioning of posterior rootlets associated with abnormal motor responses to electrical stimulation. Intrathecal baclofen therapy is useful in treating diffuse spasticity. Baclofen inhibits the activity of alpha motor neurons both pre and post synaptically at the level of the spinal cord. A decrease in Hmax/Mmax in the H-reflex electrophysiologically represents the effectiveness of these procedures. Good clinical results can be achieved by appropriate indication depending on the clinical features of spasticity in each patient.

First case report of de novo ulcerative colitis developing after orthotopic liver transplantation successfully treated by granulocyte and monocyte apheresis

BACKGROUND

Immunosuppressants such as tacrolimus and cyclosporine are prescribed long-term after orthotopic liver transplantation (OLT) to prevent allograft rejection. Although these immunosuppressants are known to effectively control ulcerative colitis (UC), some post-OLT patients develop exacerbation of preexisting UC or de novo UC. Although aminosalicylates and corticosteroid courses are usually effective to treat such UC, several patients have developed uncontrollable disease and required colectomies.

CASE REPORT

We have reported a patient who developed de novo UC after OLT to treat liver cirrhosis and hepatocellular carcinoma associated with hepatitis B virus (HBV) infection. Existence of the HBV infection made us avoid to increase the corticosteroid dose or to use other immunosuppressants such as azathioprine or infliximab.

CONCLUSIONS

In this patient, granulocyte and monocyte apheresis was highly effective in terms of inducing remission of de novo UC. No adverse event was noted.

Risk factors for the occurrence of spina bifida (a case-control study) and the prevalence rate of spina bifida in Japan

BACKGROUND

The Japanese government recommended in 2000 that women planning pregnancy should take 400 μg of folic acid daily to decrease the risk of having an infant with spina bifida. We aimed to identify risk factors for the occurrence of spina bifida and to evaluate how the prevalence rate has altered over the past 3 decades.

METHODS

Subjects comprised 360 women who gave birth to spina bifida-affected offspring and 2333 women who gave birth to offspring without spina bifida between 2001 and 2012. A self-administered questionnaire was used to collect data, which were analyzed by multiple logistic regression models. The prevalence rate of spina bifida was obtained through data provided by international and domestic organizations.

RESULTS

Four variables were significantly associated with the increased risk of having newborns afflicted with spina bifida: not taking folic acid supplements (odds ratios [OR], 2.50; 95% confidence interval [CI], 1.72-3.64), presence of spina bifida patients within third-degree relatives (OR, 4.26; 95% CI, 1.12-16.19), taking anti-epileptic drugs without folic acid (OR, 20·20; 95% CI, 2.06-198.17), and low birth weight in the newborns ≤ 2500 g (OR, 4.21; 95% CI, 3.18-5.59). The prevalence rate of spina bifida has remained 5 to 6 per 10,000 total births and has not shown any decreasing trend over the past 11 years.

CONCLUSION

Four risk factors were identified among Japanese women. Because recommendations and information have not decreased the occurrence of spina bifida, the Japanese government should implement mandatory food fortification.

Chemosensory signals and their receptors in the olfactory neural system

Chemical communication is widely used among various organisms to obtain essential information from their environment required for life. Although a large variety of molecules have been shown to act as chemical cues, the molecular and neural basis underlying the behaviors elicited by these molecules has been revealed for only a limited number of molecules. Here, we review the current knowledge regarding the signaling molecules whose flow from receptor to specific behavior has been characterized. Discussing the molecules utilized by mice, insects, and the worm, we focus on how each organism has optimized its reception system to suit its living style. We also highlight how the production of these signaling molecules is regulated, an area in which considerable progress has been recently made.

Acute subdural hematoma without subarachnoid hemorrhage caused by ruptured A1-A2 junction aneurysm. Case report

A 54-year-old man was admitted to our hospital with complaint of sudden headache. The patient had suffered two episodes of transient headache before admission. Computed tomography (CT) revealed acute subdural hematoma (ASDH) on the right side of the cerebral convexity with bilateral extension along the tentorium cerebelli without signs of subarachnoid hemorrhage (SAH) or intracerebral hemorrhage (ICH). Three-dimensional CT angiography and conventional cerebral angiography revealed a left A1-A2 junction aneurysm. Neck clipping of the aneurysm was performed. The aneurysm extended inferiorly, with the dome embedded in the chiasmatic cistern and tightly adhered to the arachnoid membrane. There was no evidence of hematoma in the subarachnoid space. The patient was discharged without neurological deficit. Ruptured aneurysms resulting in ASDH without SAH or ICH are very rare. Radiological investigation such as three-dimensional CT angiography should be performed to find the causative aneurysm in a patient with ASDH with a history of repeated headaches and without traumatic signs or episodes, and the appropriate treatment should be planned with expediency.

Multimodality treatment for cerebral arteriovenous malformations: complementary role of proton beam radiotherapy

A total of 29 cerebral arteriovenous malformations (AVMs) treated at the University of Tsukuba with multimodality treatment including proton beam (PB) radiotherapy for cerebral AVMs between 2005 and 2011 were retrospectively evaluated. Eleven AVMs were classified as Spetzler-Martin grades I and II, 10 as grade III, and 8 as grades IV and V. For AVMs smaller than 2.5 cm and located on superficial and non-eloquent areas, surgical removal with/without embolization was offered as a first-line treatment. For some small AVMs located in deep or eloquent lesions, gamma knife (GK) radiosurgery was offered. Some AVMs were treated with only embolization. AVMs larger than 2.5 cm were embolized to achieve reduction in size, to enhance the safety of the surgery, and to render the AVM amenable to GK radiosurgery. For larger AVMs located in deep or eloquent areas, PB radiotherapy was offered with/without embolization. Immediately after the treatment, 24 patients exhibited no neurological worsening. Four patients had moderate disability, and 1 patient had severe disability. Three patients suffered brain damage after surgical resection, and 2 patients suffered embolization complications. However, no neurological worsening was observed after either GK radiosurgery or PB radiotherapy, but 3 patients treated by PB radiotherapy suffered delayed hemorrhage. Fractionated PB radiotherapy for cerebral AVMs seems to be useful for the treatment of large AVMs, but careful long-term follow up is required to establish the efficacy and safety.

Navigation-guided endoscopic biopsy for intraparenchymal brain tumor

To evaluate the efficacy of intraparenchymal brain tumor biopsy using endoscopy and a navigation system (navigation-guided endoscopic biopsy) as a diagnostic tool, a case series of intraparenchymal tumor biopsies was reviewed. Navigation-guided endoscopic biopsy was applied in 9 cases, stereotactic needle biopsy in 16 cases, and open biopsy with or without navigation system in 34 cases. In all biopsy cases, 84.7% of biopsy points were sampled accurately, and 93.2% of diagnoses by biopsy were correct. Comparison of each type of biopsy showed that the resected volumes in navigation-guided endoscopic biopsy and open biopsy tended to be larger than those in stereotactic biopsy, and the mean operation time for the open biopsy procedure was the longest. To define the most applicable device or examination method to increase sampling accuracy, various factors were analyzed in 59 procedures. Navigation-guided endoscopic biopsy was the most accurate of the three types of biopsy, although the statistical difference was not significant. Older patients, histological diagnosis of high-grade glioma or malignant lymphoma, positive photodynamic diagnosis, and positive intraoperative pathology were significant factors in improving the sampling accuracy. Navigation-guided endoscopic biopsy could provide a larger sample volume within a relatively short operation time. The biopsy can be easily combined with both photodynamic diagnosis and intraoperative pathology, significantly improving the histological diagnostic yield.

Dual-port technique in navigation-guided endoscopic resection for intraparenchymal brain tumor

BACKGROUND

In navigation-guided endoscopic surgery performed via a single port, the interference of surgical instruments often disturbs the resection and hemostasis.

CASE DESCRIPTION

With regard to this, we designed a dual-port technique for navigation-guided endoscopic surgery in a 62-year-old man, with intraparenchymal anaplastic astrocytoma. Two transparent sheaths with Nelaton tubes were inserted in the front of the target lesion via an infinity-shaped burr hole, under the control of the navigation system. The lesion was removed partially using a rigid endoscope and several surgical tools through the bilateral ports. Using the new method, it was convenient to perform hemostasis with bipolar coagulation and aspiration, without any interference from the surgical instruments during the surgery.

CONCLUSION

The offered dual-port technique may be included in surgery planning for elderly patients or patients in particular conditions, with intraparenchymal brain tumors.

Intraoperative neurophysiology for surgery in and around the brainstem: role of brainstem mapping and corticobulbar tract motor-evoked potential monitoring

INTRODUCTION

New advancements of intraoperative neurophysiology for surgery in and around the brainstem have been described. NEUROPHYSIOLOGICAL TECHNIQUES: Brainstem mapping (BSM) is applied to locate cranial nerves and their motor nuclei (CMN) on the floor of the fourth ventricle. Corticobulbar tract (CBT) motor-evoked potential (MEP) monitoring is used to achieve on-line monitoring of the cranial motor nerves' functional integrity.

DISCUSSION

Each of these procedures bears a specific role: BSM can help avoid direct damage to CMNs on the fourth ventricular floor; CBT-MEP can provide simultaneous feedback on the functional integrity of the CBT and CMN during surgery, eventually leading to "tailored" modifications of the surgical procedure, based upon neurophysiological responses.

CONCLUSIONS

CBT-MEP monitoring has less restriction in terms of clinical indications, but a combination of both procedures is essential for functional preservation of CMNs during surgery in and around the brainstem.

Postnatal ascent of the cerebellar tonsils in Chiari malformation Type II following surgical repair of myelomeningocele

OBJECT

Postnatal improvement in Chiari malformation type II (CM-II) following surgical repair of myelomeningocele was evaluated.

METHODS

The authors reviewed data obtained in 20 cases in which patients underwent postnatal myelomeningocele repair within the first 48 hours after birth between October 2002 and September 2006. In 14 patients (Group 1), myelomeningocele was diagnosed in utero and the infants were delivered by cesarean section at 35-39 weeks' gestation (mean 36.4). The 6 infants in Group 2 were born after full-term gestation (39-41 weeks), and their myelomeningoceles were diagnosed postnatally. In all 20 patients, the myelomeningoceles were surgically repaired postnatally. Dynamic change of the herniated cerebellar tonsils in CM-II before and after the myelomeningocele repair, associated hydrocephalus, and symptomatic CM-II were analyzed.

RESULTS

In Group 1, the CM-II was confirmed before myelomeningocele repair in 13 cases (93%). The spinal level of the caudal end of the cerebellar tonsils ranged from C-2 to C-7. Ascent of the cerebellar tonsils was observed in 11 patients (range 1-4 spinal levels, mean 2 levels) and continued even after ventriculoperitoneal (VP) shunt placement in most patients. A VP shunt was required for the treatment of hydrocephalus in 12 patients (86%). Symptomatic CM-II developed in 8 of 13 patients (61%), 3 of whom required surgical decompression. In Group 2, CM-II was confirmed in 5 infants (83%), with the cerebellar tonsils at a spinal level of C-2 to C-4 or C-5. Ascent of the cerebellar tonsils was observed in 4 patients (range 1-1.5 spinal levels, average 1.1 levels), and no patient had symptomatic CM-II. A VP shunt was placed in 5 patients (83%). No patient was lost to follow-up during the 18-month follow-up period. The only statistically significant difference between the 2 groups was the presence of symptomatic CM-II in Group 2 (p = 0.02).

CONCLUSIONS

Patients showed ascent of the cerebellar tonsils after postnatal myelomeningocele repair. Placement of a VP shunt helped promote the ascent. However, postnatal myelomeningocele repair in the patients in Group 1 failed to consistently prevent development of symptomatic CM-II. This limited experience suggests that postnatal repair of myelomeningocele can partially reverse the anatomical CM-II, but symptomatic CM-II cannot be prevented in some patients when the repair is performed after 36 weeks' gestation.

Advanced Chiari malformation type I with marked spinal cord atrophy. Case report

The authors discuss the results obtained in patients who underwent foramen magnum decompression for longstanding advanced Chiari I malformation in which marked spinal cord atrophy was present. This 50-year-old woman presented with progressive quadriparesis and sensory disorders. Magnetic resonance imaging revealed the descent of cerebellar tonsils and medulla associated with remarkable C1-L2 spinal cord atrophy. After a C-1 laminectomy-based foramen magnum decompression, arachnoid dissection and duraplasty were undertaken. These procedures resulted in remarkable neurological improvement, even after 40 years of clinical progression. Spinal cord atrophy may be caused by chronic pressure of entrapped cerebrospinal fluid in the spinal canal.

Production and characterization of recombinant human anti-HBs Fab antibodies

Recombinant human Fab antibodies were generated with different reactivities against the hepatitis B virus surface (HBs) antigen. To isolate the antibodies, a method was used that combined transformation of human B cells by Epstein-Barr virus (EBV) infection with a primer-vector system developed for isolating DNA fragments of human Ig Fab portions. With this method, monoclonal and oligoclonal cell lines producing anti-HBs antibodies were established and three anti-HBs Fab antibodies were isolated from two of these cell lines. From analysis of affinity characteristics, immunohistochemical activity, and cytolysis activity, these three Fab antibodies were classified into three different groups. The first group had high affinity for HBs, the second had the ability to kill HBV-infected cells, and the third was applicable to immunohistochemical staining with HBV-infected cells. The combined effect of these antibodies was also investigated by complement-dependent cytotoxicity assay.

Explosive fragmentation of a thin ceramic tube using pulsed power

This study experimentally examined the explosive fragmentation of thin ceramic tubes using pulsed power. A thin ceramic tube was threaded on a thin copper wire, and high voltage was applied to the wire using a pulsed power generator. This melted the wire and the resulting vapor put pressure on the ceramic tube, causing it to fragment. We examined the statistical properties of the fragment mass distribution. The cumulative fragment mass distribution obeyed the double exponential or power law with exponential decay. Both distributions agreed well with the experimental data. Finally, we obtained universal scaling for fragmentation, which is applicable to both impact and explosive fragmentation.