In recent years, intensive molecular biological analyses of medulloblastomas have led to their categorization into distinct subgroups that differ in cytogenetics, mutational spectra, and gene expression signatures, as well as in clinical phenotypes and outcomes. The current consensus is that medulloblastomas consist of four core subgroups : WNT, SHH, Group 3, and Group 4. The biological and clinical properties of these molecular subgroups are being elucidated. The characterization and standardization of these subgroups, and their integration into the next World Health Organization (WHO) classification of central nervous system tumors are currently being discussed. The continued molecular and genetic characterization of medulloblastoma using the four-subgroup system will increase our understanding of the biology of these tumors (both primary and metastatic tumors) and lead to improved diagnosis and risk stratification systems. Furthermore, this research will contribute to the development of novel therapeutics (e. g. SMO inhibitors) and strategies.
  On the other hand, domestic research in this field has lagged. A Japanese system for the molecular diagnosis of medulloblastomas is needed, with consensus for new molecular subgroups and clinical trials based on these groups. To this end, we have formed the Japanese Pediatric Molecular Neuro-oncology Group (JPMNG) as a joint research project between the Japanese Society for Pediatric Neurosurgery (JSPN) and the Japan Society for Neuro-Oncology (JSNO), and have begun a clinical research project to establish a Japanese molecular diagnosis system for pediatric brain tumors, initially targeting medulloblastoma and ependymoma, with support from the Hospital for Sick Children (Toronto) and other international collaborators. In the JPMNG project, medulloblastoma or ependymoma tissue samples are being collected, and methods will be developed to classify them into molecular subgroups reliably and reproducibly, according to the results from gene expression analysis (using the NanoString nCounter system), immunohistochemistry, DNA sequencing by the Sanger method or next-generation sequencers, fluorescence in situ hybridization (FISH), and DNA methylation analysis.
  The molecular and genetic diagnosis of medulloblastoma is critically related to tumor classification, clinical risk stratification, and tumor biology analysis. We expect that the JPMNG project will improve the molecular diagnosis of medulloblastoma, leading to more appropriate treatments and better clinical outcomes in Japan.

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  Central nervous system germ cell tumors (CNSGCT) are more common in eastern Asia, and especially, the Japanese experience with CNSGCT has been leading the understanding and treatment of this disease. However, other countries such as the USA, Europe, and Korea have been performing clinical studies recently. The treatment strategy for germinoma is somewhat converging into the most advanced Japanese regimen. On the other hand, the basic understandings of treatments for non-germinomatous GCTs in the USA, Europe, and Japan, are still far different. We would need mutual understanding for real progress in the treatment of this rare disease in the future.

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  ‘Ventriculo-peritoneal shunting’ and ‘endoscopic diversion of the intracranial CSF pathway’ play a key role in current surgical treatment for childhood hydrocephalus.
  An adjustable gravitational valve system is a state-of-the-art mechanical design to avoid over-and under-drainage. The two-year shunt survival rate for hydrocephalus with early pediatric ages was 57.4% in our institute and 60.9% in Charite University, Berlin, respectively. Additional operations for over-drainage were performed in 6.3% of our cases. The results suggest that this system is worth setting as a guideline for hydrocephalic children but requires further refinements.
  Endoscopic third ventriculostomy (ETV) has become a routine surgical procedure and presents a more than 70% success rate. In 2009, an ETV success score (ETVSS) was proposed for the prediction of percent probability of ETV success. It is frequently used because of its usefulness regarding the indication of ETV. One of the current problems regarding ETV is late failure. The mechanisms and predictors of late ETV failure that might cause rapid deterioration are not still known. Recently, the remarkable results of endoscopic choroid plexus coagulation in combination with third ventriculostomy, reported from experience in Africa, present a new complexity to the puzzle.

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  A case of Chiari II malformation (Ch-II) may be very rare in a general hospital, but knowledge of the embryological mechanism, complications and prognosis is somewhat related to various kinds of congenital central nervous system anomalies including tethered cord syndrome and so on.
  The author herein introduces key points to determine a prognosis of Ch-II with the presentation of clinical courses and therapeutic results of thirty-six cases experienced in our hospital from January, 2001 to December, 2013. Additionally, the historical change of the treatment method, is also described with topics including prenatal diagnosis, control of combined hydrocephalus, mental development, intensive therapies and different diagnoses in cooperation with other departments, and fetal surgery for the intrauterine repair for the myelomeningocele.

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  Shaken Baby Syndrome has been widely recognized as a form of abusive head trauma. On the other hand, short falls are the most common causes given by caregivers in the cases of suspected child abuse. In order for clinicians to distinguish between abusive and accidental head trauma, the difference of the brain injury mechanism between these two situations should be clarified.
  An anthropometric infant dummy with a novel realistically shaped physical model of an infant head was developed. The three dimensional physical model of an infant head including a transparent skull, deformable brain, cerebrospinal fluid, falx, and tentorium model was reconstructed from the medical images for an infant head, which makes the intracranial brain motion visible. Intracranial brain motions during violent shaking by adult male or low height fall onto a wood floor (h=40, 80, 120 cm) were captured with high speed cameras. From the captured images, relative displacements between skull and cerebrum were measured. Threshold for bridging vein rupture based on the relative displacement of the physical models was defined from a reconstruction of cadaver experiments published by Depreitere et al.
  From the experimental results in violent shaking cases, the most important mechanism of the brain injuries was the significant change of rotational direction of the head after hyper-flexion or extension, which causes reverse rotational motion between the skull and cerebrum. In the low height fall scenario, the head impact on the surface does not directly cause a relative rotational motion between the skull and cerebrum, but neck flexion after head rebounding causes this. Therefore, the impact angle of the head strongly results in brain injury risk in these events, rather than the fall height.
  The relative displacements in violent shaking cases, which exceeded the threshold value for bridging vein rupture in most cases, were showed larger than the values in low height fall scenario. Finally, our paper clearly shows the higher subdural hematoma risk in violent shaking events.

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  A newborn boy had a dusky-red mass on his left anterior neck region and left face. The mass was hard and about 8 cm in diameter. His blood examination revealed thrombocytopenia, coagulopathy and anemia, and his chest X-ray showed cardiomegaly. The thrombocytopenia and coagulopathy with large hemangioma was diagnosed as Kasabach-Merritt phenomenon. Pharmacological and radiological treatment failed to improve his condition, and the high-output cardiac failure deteriorated to a need of continuous hemodiafiltration due to acute renal failure. Transarterial embolization with glue was performed for the congenital hemangioma on the 5th day of life. His cardiac failure as well as Kasabach-Merritt phenomenon dramatically improved after the procedure.
  Most hemangiomas in children regress spontaneously. However, some of them associate life-threatening high-output cardiac failure and consumptive coagulopathy. Transarterial embolization is required for a large hemangioma with such a condition.

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