A case of germinoma located in the fornix inducing transsynaptic atrophy of the Papez circuit.

Germinoma is a rare CNS germ cell tumor preferentially affecting children and young adults. Intracranial germinomas arise typically in the neurohypophysis and pineal region and occasionally in the basal ganglia and thalamus. Germinomas in the basal ganglia and thalamus are characterized by the ipsilateral cerebral and brainstem hemiatrophy with slowly progressive neurological deficits, which is due to tumor infiltration into the thalamocortical and corticospinal tract and induction of anterograde and retrograde Wallerian degeneration. We report an 11-year-old boy with a mass located in the fornix incidentally discovered on the first work-up of his minor head injury. Imaging findings revealed the ipsilateral atrophy of the mammillary body and the fornix. Stereotactic brain biopsy was performed and the final diagnosis was germinoma. The ipsilateral atrophy of the mammillary body and the fornix implied the transsynaptic degeneration via the Papez circuit. We discuss the unique nature of germinomas and underlying pathological mechanisms.

Exploration of an Easy and Simple Method for Decompressive Craniectomy: The "Spiral Dural Incision Method".

Decompressive craniectomy (DC) is performed to alleviate intracranial hypertension as much as possible. There are two additional goals that surgeons should strive to achieve: minimization of operating time (i.e., the time issue) and avoidance of manually pushing on the surface of the bulging brain to prevent iatrogenic brain injury (i.e., "stuffing risk"). Many authors have made progress on the time issue, but stuffing risk remains largely unmitigated. We recently presented a new DC method that resolved both issues, but the incision design was too complicated for general use. A recent study has presented a duraplasty method that does not use watertight sutures and does not exacerbate the risk associated with DC. Employing the simplified method without sutures, we developed a new, easy-to-perform DC method that resolves stuffing risk. We analyzed the incision design geometrically and verified it by simulations generated with a physics engine. Three patients with massive cerebral infarction, subarachnoid hemorrhage, and hemorrhagic infarction underwent the new procedure. The targeted incision design was composed of four or five curved incision lines. Expansion of the dura resulted in transformation into a centroclinal form with spiral rifts and canopy. The dura expanded as expected in each case, and no cases required manual stuffing of the bulging brain. The operative time was acceptable, and no complications were reported. The concept of the incision design could be applied to any polygonal duraplasty in DC. We developed a new DC method that involves a simple and easily executed incision design, avoided stuffing risk.

Filar cysts in rare cases may progress in size, particularly when associated with filar lipoma.

PURPOSE: Filar cysts (FCs) are detected incidentally on ultrasonography (US) of the neonatal spine. Their clinical significance has not been widely discussed in the literature because FCs are usually asymptomatic. This study aimed to investigate the clinical features of FCs and distinguish FCs that warrant attention. METHODS: We retrospectively analyzed 396 patients with lumbosacral skin stigmata. Patients who were younger than 1 month old at reference underwent US initially, and those older than 1 month of age underwent magnetic resonance imaging (MRI) at the age of 5-12 months. Patients with an FC in the US underwent subsequent MRI at the age of 5-12 months. Patients with an FC were followed clinically for at least 3 years. RESULTS: FCs were identified in 56 (14.1%) patients. Of the 195 children who underwent US initially, FCs were detected in 49 (25.1%) children. FCs were detected in seven children who underwent MRI initially. Of the 50 children with FCs who underwent MRI at the age of 5-12 months, FCs in 20 patients (40%) showed natural regression and FCs in 30 patients (60%) remained. Two of these 30 patients showed progression in size of the FC, and in both cases, the FCs were associated with a filar lipoma; however, the resected cysts were not neoplastic and did not have obvious clinical significance. CONCLUSIONS: Our study characterizes clinical features of filar cysts. Two-thirds of FCs remained in late infancy. The best sequence of MRI to follow-up FCs is heavily T2-weighted images.

[Rapid 3-Dimensional Models of Cerebral Aneurysm for Emergency Surgical Clipping].

We developed a method for manufacturing solid models of cerebral aneurysms, with a shorter printing time than that involved in conventional methods, using a compact 3D printer with acrylonitrile-butadiene-styrene(ABS)resin. We further investigated the application and utility of this printing system in emergency clipping surgery. A total of 16 patients diagnosed with acute subarachnoid hemorrhage resulting from cerebral aneurysm rupture were enrolled in the present study. Emergency clipping was performed on the day of hospitalization. Digital Imaging and Communication in Medicine(DICOM)data obtained from computed tomography angiography(CTA)scans were edited and converted to stereolithography(STL)file formats, followed by the production of 3D models of the cerebral aneurysm by using the 3D printer. The mean time from hospitalization to the commencement of surgery was 242 min, whereas the mean time required for manufacturing the 3D model was 67 min. The average cost of each 3D model was 194 Japanese Yen. The time required for manufacturing the 3D models shortened to approximately 1 hour with increasing experience of producing 3D models. Favorable impressions for the use of the 3D models in clipping were reported by almost all neurosurgeons included in this study. Although 3D printing is often considered to involve huge costs and long manufacturing time, the method used in the present study requires shorter time and lower costs than conventional methods for manufacturing 3D cerebral aneurysm models, thus making it suitable for use in emergency clipping.

Distraction Osteogenesis Update: Introduction of Multidirectional Cranial Distraction Osteogenesis.

In this review, we discuss in detail our current procedure for treating craniosynostosis using multidirectional cranial distraction osteogenesis (MCDO). The MCDO method allows all phenotypes of skull deformity to be reshaped by distraction osteogenesis, except in patients who are 5 months of age or younger and patients with posterior cranial vault problems. We report the results of clinical data of 36 children with craniosynostosis who underwent MCDO between 2005 and 2014 in our institute. This method has the following benefits, such as a high flexibility of reshaping, shorter treatment period and less invasive secondary intervention. We also discuss the other distraction osteogenesis techniques that are used to treat craniosynostosis and compare them with MCDO. The preferred procedure for correction of craniosynostosis may depend on the patient's age, the extent of deformity, and the extent of correction achievable by surgery. We can arrange the combinations of various methods according to the advantage and disadvantage of each technique.

[Analysis of initial treatment only by linac-based stereotactic radiosurgery for a metastatic brain tumor from non-small cell lung cancer].

A patient who receives stereotactic radiosurgery(SRS)alone for treating the brain metastatic lesion has a risk of tumor recurrence in the brain. Thus, some patients undergo prophylactic whole brain radiotherapy(WBRT)in addition to the SRS. However, the usefulness of adding WBRT is still debatable. In our hospitals, we initially treat metastatic brain tumors with SRS alone, and have experienced 2 long-surviving cases. Here, we report our treatment outcomes, including those for these 2 cases, and discuss the treatment plan for non-small cell lung cancer(NSCLC)with brain metastases. Forty-two brain metastatic cases were studied. Median survival(MS), tumor control rate(TCR), and recurrence ratio at distant site(RRDS)in the brain were analyzed. Age, Karnofsky performance status(KPS), and recursive partitioning analysis(RPA)class were analyzed as prognostic factors. We present 2 cases of a 42- and a 56-year-old man, surviving for more than 100 months. MS, TCR, and RRDS at 1 year in our hospitals were 20 months, 89.1%, and 25.6%, respectively. The prognostic factors were good KPS and RPA class and younger age. Our data showed a good MS among some reliable random controlled trials. Our strategy of SRS alone preserves the possibility to treat new lesions with WBRT. Prognosis was mainly defined by the systemic condition of the patient and activity of the primary lesion. Thorough treatment of the primary lesion with addition of SRS for initial treatment of metastatic lesions and scheduled MRI follow-up will provide for longer survival times.

Spontaneous occlusion of the frontal arteriovenous malformation and the following progression of the associated aneurysm: a case report.

We report the case of a 59-year-old women with a cerebral arteriovenous malformation (AVM) in the right frontal lobe, which was detected incidentally. Additionally, an aneurysm was found at the feeding artery of the AVM. The patient was treated conservatively. Nine years later, the nidus of the AVM was no longer detectable. The angiography showed the associated aneurysm growing irregularly with a daughter sac. The spontaneous occlusion of an AVM and the following progression of an associated aneurysm are rare. The possible mechanisms leading to the occlusion of the AVM and the progression of the associated aneurysm are discussed.

Sacrococcygeal dimple: new classification and relationship with spinal lesions.

PURPOSE: This study aims to ascertain which specific types of sacrococcygeal dimples are associated with underlying spinal cord malformations. METHODS: From 2008 to 2011, we prospectively examined children less than 2 years old with sacrococcygeal dimples. Each patient underwent clinical assessment of dimples and magnetic resonance imaging. We devised the following new classification of dimples according to their location: type 1, dimples located within the gluteal crease, including coccygeal pits; type 2, dimples located at the upper edge of the gluteal crease with associated curving or deformity of that crease; and type 3, dimples located well above the gluteal crease. RESULTS: We evaluated 142 patients with sacrococcygeal dimples. Although we identified spinal malformations such as spinal lipomas, filum cysts, and thickened fila terminalia in only 17 % of infants with type 1 dimples, we observed them in 45 % with type 2 and 55 % with type 3. Thus, in terms of the rate of spinal malformations, there are significant differences between types 1 and 2 and between types 1 and 3. CONCLUSIONS: We propose a new classification of sacrococcygeal dimples. Although type 2 dimples have previously been classified as simple dimples that require no further investigation, we have identified that they are strongly associated with spinal deformities, comparable to atypical type 3 dimples. Thus, both types 2 and 3 dimples warrant radiological investigation.

Planar geometrical analysis for design of the shortest incision to open the dura mater: technical note.

Quadrilateral dural window is opened with a conventional incision design, such as a pair of diagonal lines or a rectangular shape, but the total cutting length is not the shortest possible. Shorter incision length will have a lower risk of dysraphia associated with cerebrospinal fluid (CSF) liquorrhea or related CSF infection. We propose a new and effective dural incision design with the shortest cutting length for quadrilateral dural openings. We investigated the design of the dural incision using a simple planar geometrical figure. We discovered the shortest network design to connect the four vertices of the quadrilateral. The shortest network design was formed of five line segments with two three-pronged interconnections (TPIs) with the same angle of 2π/3 between any two lines (2π/3-TPI). In practice, first we must draw a quadrilateral W horizontally then add two equilateral triangles outside W. Using a 2π/3-bent wire, the 2π/3-TPIs are traced on the path connecting the outward vertices of the equilateral triangles. Using this method, we can reduce the incision length by 10% from conventional designs using a pair of diagonal lines.