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Study Design: Retrospective cohort study.Purpose: This study aimed to elucidate cases for which staged surgeries are effective by a retrospective review of previous operative cases of spinal ependymomas.Overview of Literature: Patients with spinal ependymomas are expected to have a good prognosis following total resection. However, forcible dissection of spinal ependymomas will lead to neurological deterioration. Moreover, resection is sometimes difficult when the tumor is large. We have performed two-stage surgeries for large spinal ependymomas, but the indication of staged surgery is unclear.Methods: We retrospectively reviewed patients diagnosed with spinal ependymomas who underwent tumor resection in our institution. We obtained data regarding patients’ clinical characteristics, tumoral radiological characteristics, and surgical factors and compared them to clear prognostic factors. Two-stage surgery was performed in 11 patients (36.7%), and single surgery was performed in 19 patients (63.3%).Results: Thirty patients were included in the analyses and divided into two groups: single surgery and two-stage surgery groups. In the single surgery group, high tumor–cord ratio (TCR) and intraoperative motor evoked potential (MEP) reduction were significantly correlated with unfavorable outcomes, which were defined as deterioration of the modified McCormick scale grades 2 months and 1 year postoperatively. Alternatively, these factors were not significantly correlated with postoperative unfavorable outcomes in the two-stage surgery group. Receiver operating characteristic curves indicated that TCR of 0.866 yielded 85.7% sensitivity and 83.3% specificity 2 months postoperatively.Conclusions: The results suggested that high TCR might be an indication of two-stage surgery and that its cutoff value is 0.866. Moreover, switching from single surgery to two-stage surgery may prevent postoperative neurological deterioration when intraoperative MEP is decreasing.

Moment Tensors of hydraulically induced AEs: Hydraulic fracturing is an important technique in the development of enhanced geothermal systems and unconventional resources. Although the fracture modes induced by hydraulic fracturing influence the recovery efficiency of the resources, the current understanding of this relationship is insufficient. In this study, we considered the acoustic emissions (AEs) induced during hydraulic fracturing under uniaxial loading conditions in the laboratory, and applied a moment tensor analysis by carefully correcting the coupling condition and directivity of AE transducers. Experiments were conducted for two types of Kurokami–jima granite samples: those with a rift plane perpendicular (Type H) or parallel (Type V) to the expected direction of fracture propagation (i.e. along the loading axis). In the experiments, both sample types experienced a significant number of shear, tensile and compressive events. The dominant fracture mode for Type H samples is found to be tensile events in which the fracture plane is parallel to the loading axis, whereas for Type V samples, shear events are dominant. This difference suggests that the dominant fracture modes induced by hydraulic fracturing are highly dependent on the relationship between the direction of fracture propagation and orientation of pre-existing weak planes.

Study Design: A retrospective cohort study. Purpose: To examine the validity of prophylactic surgery for children with tethered cord syndrome (TCS). Overview of Literature: Prophylactic surgery for pediatric patients with TCS remains controversial. Methods: We retrospectively analyzed the surgical outcomes of 14 children (nine boys and five girls) with asymptomatic TCS who were surgically treated at Hokkaido University Hospital between 1989 and 2015. Results: The median age at the time of initial surgery for asymptomatic TCS was 28.6 months (range, 0-66 months). The median final follow-up period was 142 months (range, 7-232 months). Of the 14 children with asymptomatic TCS, 12 had lumbosacral lipoma and two had meningocele. According to the classification of spinal lipoma, two children had dorsal type, four had caudal type, two had transitional type, and four had filar type. There were no children with lipomyelomeningocele. All children were free of neurological symptoms until 94 months after the initial surgery. Subsequently, one child exhibited delayed neurological deficits and underwent a second surgery because of motor and sensory disturbances; slight sensory disturbance was noted at the final follow-up examination. Another child later showed bowel and bladder dysfunction. However, a second surgery was not performed for this child because his motor and sensory functions were normal; hence, we chose to avoid nerve injury in the case of dissecting adhesion. Conclusions: All 14 children with asymptomatic TCS were free of neurological symptoms until 94 months after the initial surgery. However, two children exhibited delayed neurological deficits at 94 months and 177 months. We believe that prophylactic surgery for asymptomatic TCS is effective for a certain period. However, because the natural history of TCS is poorly understood, strict follow-up after surgery is necessary.

We investigated the relation between seismic events and fractures induced by hydraulic fracturing in laboratory experiments under uniaxial loading conditions using granite and shale blocks by monitoring acoustic emissions (AEs). We used a thermosetting acrylic resin mixed with a fluorescent compound as the fracturing fluid and fixed it within the blocks by heating immediately after fracturing. This allowed observation of fluid penetration regions and fracturing patterns on cross-sectional planes under ultraviolet light irradiation. The obtained AE hypocenters and resin penetration regions observed after the fracturing extended on both wings along the loading axis from the fracturing hole for all the samples. This was as expected theoretically, although the AEs were concentrated primarily on only one side for some samples. Patterns of wellbore pressurization histories, AE activities, and resin penetration regions were significantly different between the two rock types. In the experiments using granite samples, wellbore pressure increased linearly until 87.2–97.4% of the peak pressure, followed by a gradual decrease of the rate and sudden drop of pressure (breakdown). AEs started to occur at 49.6–93.2% of the peak pressure, significantly before the breakdown. Resin penetration regions have a width of 10–30 mm and such wide penetration regions resulted in indistinguishable main fractures. For the shale samples, both the nonlinearity of the wellbore pressure–time curve and the AE activity were initiated immediately before breakdown. The number of detected AEs was much smaller than for the granites. Resin in the rock samples showed thin traces with widths of

Study Design: Retrospective cohort study. Purpose: To compare long-term results of surgery with the outcomes of symptomatic and asymptomatic tethered cord syndrome (TCS) in children and adolescents and to assess the surgery duration for those with TCS. Overview of Literature: Pediatric patients with TCS continue to pose significant diagnostic and management challenges. Methods: We retrospectively analyzed the outcomes of 31 patients (16 males, 15 females) with TCS, including 21 with lumbosacral lipoma. All were surgically treated between 1989 and 2015. They were divided into symptomatic and asymptomatic TCS groups. The results of the treatment were summarized and analyzed using a non-parametric Mann-Whitney U test. Results: Nineteen patients had symptomatic TCS and 12 had asymptomatic TCS. Patients had a median age of 34 months (range, 0-201 months). The median follow-up period was 116 months (range, 7-223 months). Of the 19 symptomatic TCS patients, preoperative deficits improved after surgery in two (10.5%) and remained stable in 17 (89.5%) patients. One of the 12 asymptomatic TCS (8.3%) patients showed an exacerbated illness after surgery, and one in 11 patients remained stable (11.7%). There were significant differences in monthly age at surgery, preoperative bowel and bladder dysfunction, neurological function, presence/absence of clean intermittent catheterization introduction, and presence/absence of motor disorder at final follow-up (all p

Purpose: To examine the validity of our treatment strategy for spinal dural arteriovenous fistulae (SDAVF), based on the treatment results and the long-term outcome. Methods: This study included 50 SDAVF patients (38 men, 12 women, mean age 63.2 years) with progressive myelopathy. The treatment strategy involved embolization as the initial management tool and surgery if embolization was considered unsuitable. Their medical records were evaluated to identify the treatment results and functional outcomes. The mean follow-up period was 81.2 months (range 27 - 184 months). Results: Complete obliteration was achieved in 22 (71.0%) of 31 embolized patients and in 18 of 19 (94.7%) operated patients. The initial success rate was significantly lower in embolized- than operated patients. At the last follow-up, 33 of the 50 patients (66%) manifested improved gait and 16 (32%) improved micturition. The activity of daily living (ADL) was improved in 33 (66%). When we compared the rates of functional improvement at the last follow-up, there was no significant difference between patients treated initially by embolization or surgery. Conclusions: The long-term outcomes in SDAVF patients treated by multidisciplinary management with first-line embolization were comparable to those in earlier surgical series. However, our results were unable to demonstrate the superiority of endovascular embolization to surgical treatment for SDAVF. For the purpose of justifying endovascular embolization as a first-line treatment for SDAVF, it will be necessary to show further improvement in both the initial treatment success and the complication rates.

The effects of a gel network structure on purple membrane (PM) spontaneous stacking are discussed, with particular emphasis on the relationship between the PM periodic pre-structures before gelation. Such peculiar intermembrane pre-structures with a periodic distance of ∼20 nm have recently been found to provide an important key to PM stacking, which is critical for the engineering applications of PM. Here, we investigated how the PM stacking differs depending on the gel network of a poly(vinyl alcohol) gel. On the basis of the results, we propose a plausible interplay between the PM periodic pre-structures and the type of gel network for PM stacking. The results indicate that a porous gel network, in addition to the PM periodic pre-structure in solutions, is necessary for PM stacking in immobilized gel samples.

BACKGROUND Chronic pain due to spinal dural arteriovenous fistulae (SDAVF) during follow-up is a serious issue because it can affect patients' quality of life. The severity of posttreatment chronic leg pain in patients with SDAVF is unclear. OBJECTIVE To investigate the prevalence, severity, and characteristics of chronic leg pain in patients with SDAVF and to examine the clinical factors associated with chronic pain. METHODS We conducted a survey of their chronic posttreatment leg pain in 49 SDAVF patients. It consisted of a numeric rating scale and a neuropathic pain symptom inventory (NPSI). Of the 49 patients, 32 (65.3%) completed the questionnaire. There were 24 males and 8 females whose mean age was 69.1 years. The mean follow-up period was 86.3 months. RESULTS Chronic leg pain was reported by 26 (81.3%) of 32 patients; 14 experienced pain before treatment and 12 had new-onset posttreatment pain. The pain was reported as moderate to severe by 21 (80.8%) of 26 patients; the mean numeric rating scale and NPSI scores were 6.0 ± 2.3 and 17.4 ± 10.3, respectively. The NPSI subscores were significantly higher for spontaneous pain and paresthesia/dysesthesia than for paroxysmal pain. We found no significant clinical factors related to chronic posttreatment pain; on magnetic resonance imaging scans we identified spinal cord atrophy in 8 patients with chronic pain. CONCLUSION Most of our SDAVF patients reported moderate to severe chronic leg pain characterized by spontaneous pain and paresthesia/dysesthesia. Spinal cord atrophy on magnetic resonance imaging scans was a characteristic in patients with chronic pain.

Rationale Rosette-forming glioneuronal tumor (RGNT) is a rare tumor which has been first reported as the fourth ventricle tumor by Komori et al and is classified as a distinct clinicopathological entity by the WHO Classification of Tumors of the Central Nervous System as in 2007. Although RGNTs were reported to occur in both supratentorial and inflatentorial sites, only 4 case reports of spinal RGNT have been demonstrated. Patient concerns A 37-year-old female presenting with slowly progressing right-sided clumsiness. Cervical magnetic resonance imaging revealed a spinal intramedullary tumor between the C2 and C5 levels. Diagnoses Pathological analysis showed unique biphasic cellular architecture consisting of perivascular pseudorosettes dominantly with few neurocytic rosettes and diffuse astrocytoma component. The tumor cells composed of perivascular pseudorosettes showed positivity for both synaptophysin and glial markers such as GFAP and Olig2. Therefore, the diagnosis of RGNT was made. Interventions Gross total resection of the tumor was achieved. No adjuvant chemotherapy nor radiotherapy was conducted after operation. Outcomes At 2 years after the operation, no recurrence was observed. Lessons Although RGNT arising from the spinal cord is extremely rare, we need to consider the tumor as a differential diagnosis for intramedullary spinal cord tumors.

Spinal lipomas are rare, accounting for less than 1% of all spinal tumors. Most are associated with spinal dysraphism. Spinal lipomas without spinal dysraphism are uncommon;they are typically subpial tumors. Some tumors are located both inside and outside the dura mater (so-called "dumbbell-type"). Herein, we report a patient with a dumbbell-type thoracic spinal lipoma. A man in his 50's complained of progressive gait disturbance, dysesthesia in his left leg, and hyperesthesia in his right leg. His symptoms were worsened by exercise. CT and MRI revealed a thoracic spinal lipoma extending from the spinal cord to the intervertebral foramen at the Th 6-8 level. He underwent partial tumor removal and untethering. Postoperatively he reported gradual symptom abatement. Dumbbell-type spinal lipomas are very rare. Besides partial removal of the tumor, untethering should be considered when symptoms are associated with tethering of the spinal cord.

A 69-year-old man presented with a very rare case of primary central nervous system lymphoma originating in the cauda equina manifesting as progressive paraparesis. The patient underwent a biopsy, and was treated with intravenous high-dose (3.5 g/m(2)) methotrexate chemotherapy and local irradiation. Histological study revealed large B cell type lymphoma. Follow-up magnetic resonance imaging showed complete remission of the lesion, but the patient died of pneumonia at 18 months after the initial onset without tumor recurrence, so the efficacy of this strategy remains unknown.

Intramedullary spinal cord abscess (ISCA) without meningitis is an extremely rare entity in the central nervous system, and it is often difficult to diagnose immediately, and no definitive imaging findings have been established. We experienced the case of a 61-year-old male who presented with a sudden onset back pain without fever following rapidly worsening paraparesis for 3 days, who subsequently become unable to walk. According to the initial MRI and 3D-CTA, the presumptive diagnosis was spinal infarction due to spinal artery embolism. However, his symptoms did not improve, despite the gradual changes in MRI following antiplatelet therapy. He underwent a biopsy in an attempt to prevent the lesion from progressing toward the upper spinal cord. The pathological examination revealed an intramedullary abscess, so we performed a midline myelotomy and drained the pus from the abscess. After surgery, MRI showed improvement, but the patient’s paraplegia persisted. To the best of our knowledge, this is the first case report of spinal cord abscess with the confirmation of spinal artery occlusion on angiography, which could have been caused by a bacterial embolism. We herein discuss its possible etiology and also review recent reports on ISCA.

The authors reported a case of cervical juxtafacet cyst with extensive rim enhancement on gadolinium-diethylenetriamine pentaacid magnetic resonance imaging. Operative finding revealed the epidural space around the mass filled with abundant venous plexus. Histological examination demonstrated that cyst wall was composed of the well-vascularized fibrous connective tissue with some inflammatory changes. We speculate that extensive rim enhancement of juxtafacet cyst may be attributed not only to the chronic inflammatory changes of cyst wall, but to engorged venous plexus within the widened epidural space.

Transplanted bone marrow stromal cells (BMSC) promote functional recovery after spinal cord injury (SCI) through multiple mechanisms. A Rho kinase inhibitor, Fasudil also enhances axonal regeneration. This study was aimed to evaluate whether combination therapy of BMSC transplantation and Fasudil further enhances axonal regeneration and functional recovery in rats subjected to SCI. Fasudil or vehicle was injected for 2 weeks. BMSC or vehicle transplantation into the rostral site of SCI was performed at 7 days after injury. Neurological symptoms were assessed throughout the experiments. Fluoro-Ruby was injected into the dorsal funiculus of the rostral site of SCI at 63 days after injury. The fate of the transplanted BMSC was examined using immunohistochemistry. BMSC transplantation significantly increased the number of Fluoro-Ruby -labeled fibers of the dorsal corticospinal tracts at the caudal site of SCI, enhancing functional recovery of the hind limbs. Some of the engrafted BMSC were positive for Fluoro-Ruby, neuronal specific nuclear protein and microtubule-associated protein-2, suggesting that they acquired neuronal phenotypes and built synaptic connection with the host's neural circuits. Fasudil treatment also improved axonal continuity, but did not promote functional recovery. Combination therapy dramatically increased the number of Fluoro-Ruby-labeled fibers of the dorsal corticospinal tracts at the caudal site of SCI, but did not further boost the therapeutic effects on locomotor function by BMSC transplantation. The findings suggest that BMSC transplantation and Fasudil provide synergistic effects on axon regeneration after SCI, although further studies would be necessary to further enhance functional recovery.

The aim of lumbar disc herniation surgery is the removal of herniated disc material (HDM) and complete decompression of the nerve root. As some patients present with residual HDM, we examined the ability of intraoperative ultrasound (IOUS) to detect this material. Between February 2006 and June 2007, we used IOUS in 30 patients undergoing surgery for lumbar disc herniation. They were 17 men and 13 women; their ages ranged from 22 to 63 y (mean 44.0 y). The level surgically addressed was L3/4 in 1, L4/5 in 14 and L5/S1 in 15 patients; they were operated in the prone position. After placing a 3-4 cm midline skin incision, partial hemi-semilaminotomy was performed. HDM was removed through a bone window; a surgical microscope was used during the operation. After removal was judged as adequate, IOUS was performed; 17 patients also underwent IOUS before removal of the herniated disc. For the acquisition of IOUS images, we used LOGIQ 9 and 8c microconvex probes (GE Healthcare, Wauwatosa, WI, USA). The normal anatomical structures were well visualized. HDM was iso- to hyperechoic compared with normal nerve tissue. In three of 17 patients, the dural sac and nerve root could not be distinguished from HDM before removal, although in all 30, the decompressed dural sac, intradural cauda equina and nerve root were well visualized. We posit that the echogenicity of nerve tissue was raised due to compression, rendering it similar to that of the herniated disc. In two patients, IOUS detected residual disc material; the surgical procedure was resumed and sufficient removal was accomplished. IOUS monitoring is safe, convenient and inexpensive. It is also highly useful for the detection of residual HDM and the confirmation of adequate nerve root decompression.

OBJECTIVE: Recent studies have indicated that bone marrow stromal cells (BMSCs) have the potential to improve neurological function when transplanted into animal models of spinal cord injury (SCl). However, it is still unclear how the transplanted BMSCs promote functional recovery after SCI. In this study, therefore, we evaluated how the transplanted BMSCs restore the function of the dorsal corticospinal tracts in the injured spinal cord. METHODS: The rats were subjected to incomplete SCI by means of a pneumatic impact device. BMSC or vehicle transplantation into the rostral site of SCl was performed at 7 days after injury. Neurological symptoms were assessed throughout the experiments. Fluoro-Ruby was injected into the dorsal funiculus of the rostral site of SCl at 63 days after injury. The fate of the transplanted BMSCs was examined using immunohistochemistry. RESULTS: BMSC transplantation significantly enhanced functional recovery of the hind limbs. The number of Fluoro-Ruby-labeled fibers of the dorsal corticospinal tracts at the caudal site of SCI was significantly higher in the BMSC-transplanted animals than in the vehicle-transplanted animals. Some of the engrafted BMSCs were positive for Fluoro-Ruby, NeuN, and MAP2 in the gray matter, suggesting that they acquired neuronal phenotypes and built synaptic connection with the host's neural circuits. Others in the white matter morphologically simulated the astrocytes and were also positive for glial fibrillary acidic protein. CONCLUSION: The findings suggest that the transplanted BMSCs acquire neural cell phenotypes around the injury site and contribute to rebuild the neural circuits, including the corticospinal tract, promoting functional recovery of the hind limbs.

A 65-year-old woman presented with a rare case of cervical epidural arteriovenous fistula (AVF) manifesting as radiculopathy of the right upper extremity that mimicked cervical spondylosis. She had a 2-month history of gradually progressive right-hand motor weakness and sensory disturbance. The initial diagnosis was cervical disk herniation. However, computed tomography with contrast medium showed abnormal enhancement at the right C5-6 and C6-7 intervertebral foramina. Magnetic resonance (MR) imaging with gadolinium disclosed an enhanced abnormal epidural mass at the dorsal surface of the dural tube between the C5 and C6 vertebrae. T(2)-weighted MR imaging showed a slight flow void on the dorsal and ventral surfaces of the spinal cord between C3 and T4. Digital subtraction angiography disclosed cervical epidural and dural AVFs fed by the C5 and C6 radicular arteries. The diagnosis was concomitant epidural and dural AVFs. The dilated internal vertebral venous plexus attributable to epidural AVF was considered to be responsible for the radiculopathy. Transarterial embolization using n-butylcyanoacrylate achieved complete occlusion of the lesions. Her symptoms improved immediately and MR imaging and angiography performed 10 days postembolization showed reduction of both the epidural and dural AVFs.

OBJECTIVE We sought to describe a minimally invasive two-stage operation for huge cervical intramedullary schwannomas. CLINICAL PRESENTATION Two patients with intramedullary schwannomas at C1-C2 and C5-C7 underwent two-stage surgery. In both patients, preoperative magnetic resonance imaging revealed the presence of a large tumor. INTERVENTION The first surgery included partial tumor removal and duroplasty. At the time of the second operation performed 10 days later, the residual tumor was removed completely. CONCLUSION Magnetic resonance imaging performed before the second operation demonstrated marked degeneration of the tumor in one patient and recovery of the spinal cord in both. We succeeded in removing the residual tumors entirely during the second operation. Neither patient manifested new neurological deficits, although one of the patients experienced transient left-hand weakness. Our two-stage operation is very useful for the resection of huge intramedullary schwannomas and preserves neurological function.

A surprising shortage of information surrounds the mechanism by which bone marrow stromal cells (BMSC) restore lost neurologic functions when transplanted into the damaged central nervous system. To clarify the issue, the BMSC were cocultured with the neurons using two paradigms: the cell-mixing coculture technique and three-dimensional coculture technique. The green fluorescent protein (GFP)-expressing BMSC were cocultured with the PKH-26-labelled neurons, using cell mixing coculture technique. GFP-positive, PKH-26-negative cells morphologically simulated the neurons and significantly increased the expression of MAP-2, Tuj-1, nestin, and GFAP. GFP/nestin-positive, PKH-26-negative cells increased from 13.6% +/- 6.7% to 32.1% +/- 15.5% over 7 days of coculture. They further enhanced Tuj-1 expression when cocultured with neurons exposed to 100 microM of glutamate for 10 min. About 20-30% of GFP-positive cells became positive for PKH-26 through coculture with the neurons, but the doubly positive cells did not increase when cocultured with glutamate-exposed neurons. Alternatively, the BMSC significantly ameliorated glutamate-induced neuronal damage when cocultured with the three-dimensional coculture technique. The protective effect was more prominent when coculture was started prior to glutamate exposure than when coculture was started just after glutamate exposure. ELISA analysis revealed that the BMSC physiologically produce NGF, BDNF, SDF-1alpha, HGF, TGFbeta-1, and IGF-1 and significantly enhanced the production of NGF and BDNF when cocultured with glutamate-exposed neurons. These findings strongly suggest that the BMSC may protect and repair the damaged neurons through multiple mechanisms, including transdifferentiation, cell fusion, and production of growth factors.

The incidence of cervical spondylosis in the elderly is increasing with the higher proportion of elderly individuals among the Japanese population. The present study retrospectively analyzed the clinical and radiological features of this clinical entity in 107 patients with cervical spondylosis aged 70 years or older surgically treated between 1995 and 2005. The patients were divided into Group 1 (n = 60) aged between 70 and 74 years, and Group 2 (n = 47) 75 years or older. Patients with localized compression within 2 levels responsible for the neurological symptoms underwent anterior fusion, and patients with a narrow spinal canal were treated by laminoplasty. The pre- and postoperative neurological status (Neurosurgical Cervical Spine Scale) and postoperative complications were compared. More patients in Group 2 required laminoplasty but most patients underwent single-level anterior fusion. There was no statistically significant difference in the surgical results. Group 2 had a much higher ratio of anterior fusion at the C3-4 level. Many of the aged patients had multiple risk factors. Surgical decompression for cervical spondylosis is beneficial even in elderly patients. Single-level anterior fusion to treat the lesion most responsible for the symptoms is the least invasive choice. Elderly patients tend to present with multiple risk factors so require careful perioperative management.

The present study evaluated the effect of the free radical scavenger edaravone on lesion volume and neurological dysfunction after spinal cord injury (SCI) in mice, and investigated its protective effects on superoxide generation. Female C57BL/6 mice were subjected to SCI using a pneumatic impact device and were treated with 3 mg/kg of edaravone or vehicle 30 minutes before the insult. Motor functions were quantitatively evaluated. Lesion volume was assessed by Dohrmann's two-cone method after one week. In situ detection of superoxide in the injured cord was carried out using the superoxide-sensitive dye dihydroethidium (DHE) staining technique. Pretreatment with edaravone significantly improved motor dysfunction and reduced the lesion volume to about 63% of the control (p < 0.05). Semi-quantitative measurements of red fluorescence emitted from DHE revealed that the superoxide concentration increased in the lesion periphery at 1 and 3 hours after the insult, and that pretreatment with edaravone significantly inhibited the increase of superoxide concentration in the lesion periphery at both time points (p < 0.0001). Double staining with DHE and monoclonal antibody against MAP2 showed that most cells positive for DHE were also positive for MAP2. These findings suggest that edaravone ameliorates tissue damage by scavenging reactive oxygen species, especially in the neurons, after SCI.

A 33-year-old man presented with a rare case of lumbar epidural venous varix causing radiculopathy manifesting as sciatica exacerbated during bowel movements. The left straight-leg raising test was positive and patellar tendon reflex was lost. Lumbar magnetic resonance imaging showed a mass lesion in the epidural space at the L4 level just anterior to the dural sac on the left, appearing as hypointense on T1- and hyperintense on T2-weighted images, with ring-like enhancement with gadopentetate dimeglumine. He underwent surgery under a preoperative diagnosis of cystic nerve sheath tumor. After left hemilaminectomy, intraoperative ultrasonography showed a low echoic mass lesion ventral to the L4 nerve root. The mass was dark blue with a smooth wall. Tearing of the wall resulted in continuous bleeding. After removal of the lesion, we confirmed that the dura of the nerve root was intact. Histological examination of the surgical specimen confirmed venous tissue. The postoperative course was excellent. Lumbar epidural varix is difficult to diagnose preoperatively. Lumbar epidural varix should be considered if the lesion is smaller on preoperative than intraoperative imaging, or disap- pears with bleeding cessation, as this may avoid unnecessary widening of the operative field. The correct preoperative diagnosis remains difficult, so we recommend surgical removal and histological confirmation.

Atypical teratoid/rhabdoid tumor (AT/RT) occurring in the central nervous system is a high-grade malignant tumor, and its prognosis is poor for patients younger than 3 years of age. In this article, we present a case of infant AT/RT in the cervical spine and its successful treatment by intensive chemotherapy. The patient, a 1.75-year-old girl, developed an acute, progressive tetraparesis. MRI revealed a large, intradural mass in the cervical spine.Total surgical resection was performed, and the specimen was diagnosed as AT/RT. Continuously, she received intensive chemotherapy using thiotepa with autologous bone marrow transplantation. At the age of nearly 3 years, she received radiation therapy to the local tumor bed and craniospinal axis. She is now 4 years old and has been maintained in complete remission with a good clinical course and no neurological deficit. The success of this treatment for the patient was that we could prevent tumor recurrence until she was able to receive radiotherapy.

Neurological improvement in patients with spinal dural arteriovenous fistulae (SDAVF) is often partial even after adequate treatment. While treatment outcomes have been evaluated primarily on the basis of the postoperative changes in neurological deficits, outcome measures should also reflect the patient-reported outcome (PRO). We conducted a health-related quality of life (HRQOL) survey in 52 SDAVF patients; 33 (63.5%) completed the short-form 36 Health Survey (SF-36) questionnaire. They were 25 males and 8 females ranging in age from 47 to 85 years (mean age 70.0 years). The mean follow-up period was 95.6 months. We analyzed the completed questionnaires and examined the clinical factors associated with their HRQOL. After treatment, gait- and micturition disturbances persisted in 31 (93.9%) and 31 (93.9%) of our patients; 26 (78.8%) reported chronic leg pain. The SF-36 scores of treated SDAVF patients were significantly lower than the national average of 50 for all 8 sub-items in the questionnaire. The scores for physical functioning (PF) and role-physical (RP) were particularly low. With the exception of bodily pain (BP), there was a significant negative correlation between the Aminoff-Logue scale (ALS) scores for gait- and micturition and the sub-item scores. The score for BP showed a significant positive correlation with the scores for the 7 other SF-36 sub-items. The HRQOL of treated SDAVF patients was lower than the national average with respect to both physical and mental aspects. Persistent post-treatment pain and gait- and micturition disturbances were responsible for their lower HRQOL.

In development of unconventional reservoirs such as tight and shale oil/gas reservoirs, hydraulic fracturing has been applied to enhance reservoir productivity. In spite of active applications of hydraulic fracturing, a shape of induced fractures is not fully understood. This paper presents the result of laboratory visualization experiment of hydraulic fracturing, which was conducted to visualize the shape of induced factures with cylindrical shale sample through the fluorescent method. An acrylic resin mixed with a fluorescent agent was used as a fracturing fluid. The resin is solidified and fixed within the samples by heat. The shape of the induced facture reveals based on different brightness under ultraviolet light irradiation. Many associated microfractures were observed around the main fractures. The fracturing fluid can be trapped in these types of microfractures by capillary force and these fractures cause lower recovery of fracturing fluid in the actual field operations. Acoustic emission (AE) was also monitored by the 16 sensors mounted the rock samples. Result from the path of main fractures identified by the resin mixed with a fluorescent substance and distribution of AE indicates good agreement between two. This helps us to examine which particular failure generates microseismicity. Although the scale difference between laboratory experiments and field operations needs to be taken into account, the shape of induced fractures is successfully characterized. We interpret the fluid leak off zone, main fracture, and branch fractures can be a source of the AE while no AE is observed at the area of the fracture with large aperature based on overlaying AE hypocenters with visualized induced fracture. This work helps engineers to make a proper model of hydraulic fractures for the estimation of well productivity.

Background In spinal surgery, repair of the dura is difficult when it is torn or fragile or is ossified as in cases with ossification of posterior longitudinal ligament. We report our experience with a nonsuture dural repair technique in patients undergoing spinal surgery; it uses a dura substitute composed of polyglycolic acid (PGA) mesh and fibrin glue. Here, we report the efficacy and safety of nonsuture duroplasty using PGA mesh and fibrin glue (PGA-fibrin sheet). Methods The artificial dura mater is composed of a PGA-fibrin sheet. The dural defect is covered with a patch sprayed with fibrin glue without suturing to the dura mater. We first evaluated this technique in an experimental study by performing water leakage tests. Between May 2001 and January 2005, we used it in 160 spinal surgeries that required intraoperative dura repair. Results Our preliminary tests showed that the threshold for water pressure without leakage was 161 ± 42 and 96.5 ± 32 mm Hg when the unsprayed margin around the perimeter of the patch was 5 and 2 mm, respectively. Of the 160 operated patients, 10 (6.3%) experienced subcutaneous cerebrospinal fluid (CSF) leakage. Of these, 6 required a second operation; in the other 4, the CSF collection diminished spontaneously. There were no other complications such as allergic reaction, adhesion, or infection. Conclusion In combination with CSF diversion, the PGA-fibrin sheet is a viable alternative method for dural repair in spinal surgery.

The present study was aimed to clarify the proliferation capacity of the bone marrow stromal cells (BMSC) transplanted into the brain. The BMSC were harvested from green fluorescence protein (GFP)-transgenic mice, grown to the confluency and passed three times. They were labeled by co-culture with Ferucarbotran, a superparamagnetic iron oxide (SPIO) agent. The proportions of the SPIO-positive cells were evaluated from P3 to P7, using Turnbull blue staining. The GFP-BMSC labeled by Ferucarbotran were transplanted into the ipsilateral striatum of the mice brain subjected to permanent focal ischemia at 7 days after the insult. The distribution and differentiation of GFP- and SPIO-positive cells in the brain were studied 3 months after transplantation, using immunohistochemistry and Turnbull blue staining. As the results, the proportions of the SPIO-positive cells gradually decreased from 93.6% at P3 to 6.5% at P7. Fluorescence immunohistochemistry revealed that the GFP-positive cells were widely distributed around infarct and partially expressed MAP2 and NeuN 3 months after transplantation. However, only a smaller number of SPIO-positive cells could be detected on Turnbull blue staining. The ratio of the SPIO- to GFP-positive cells was approximately 2.7%. The results strongly suggest that the BMSC repeat proliferation many times, migrate into the lesion, and partially express the neuronal phenotype in the host brain during 3 months after transplantation. The double labeling technique would be valuable to prove the proliferation of the transplanted cells in the host tissue because GFP gene and SPIO nanoparticles have different inheritance characteristics.

A 62-year-old male presented with a rare case of ligamentum flavum hematoma manifesting as low back pain and gait difficulty beginning 1 month before consulting our institute. He had no history of lumbar spine surgery or lumbar puncture. However, he might have suffered forgotten back injury while practicing martial arts. Magnetic resonance imaging showed a heterogeneous intensity mass lesion with a cystic component at the L3-4 levels. The lesion was totally removed through a hemilaminectomy. Intraoperative and histological findings confirmed the diagnosis of old hematoma with granulomatous change in the ligamentum flavum. Postoperatively, his low back pain and gait difficulty resolved within a few days.

In order to verify the biological aspects of 'autogeneic' bone marrow stromal cells (BMSC) transplantation for neurological disorders, we aimed our study towards the assessment of the survival, distribution, and differentiation of autologous BMSC in the central nervous system (CNS). We harvested rat BMSC from femur bones, and the nuclei were then fluorescently labeled by a 24-h co-culture with bis-benzimide. These BMSC were stereotactically injected into the striatum (n=6) or thoracic cord (n=8) of each animal. We evaluated the distribution and differentiation of 'autogeneic' BMSC in the brain and spinal cord after 4 weeks, using the immunohistochemistry technique. We found some injected cells in the ipsilateral striatum, hippocampus, neocortex, and bilateral corpus callosum, and approximately 20% and 15% of the engrafted cells expressed neuronal and astrocytic markers, respectively. Other injected cells were distributed in the dorsal funiculus and adjacent gray matter, and about 10% and 15% of these cells expressed neuronal and astrocytic markers, respectively. Although the precise mechanism of BMSC transdifferentiation still remains unclear, the present results show that 'autogeneic' BMSC could highly differentiate into their own CNS neural cells, suggesting that they are surrounded by favorable conditions.

The authors describe a rare case of hemangiopericytoma with cervical metastasis. A 34 year-old man with a history of intracranial hemangiopericytoma complained of a weakness of his right hand. Both CT scan and MR imaging demonstrated homogeneous enhanced tumor in his C5 vertebral body, right facet joint and lamina. Preoperative embolization was performed in order to decrease bleeding during the operation. A two-stage operation was performed because the tumor was considered to be too large to remove all at once. First, from the anterior, partial tumor resection and C5 corpectomy were done followed by anterior fusion with a cervical plate. After which, a secondary surgery was carried out from the posterior. The gross total tumor removal was accomplished successfully by these procedures. Histological findings revealed typical hemangiopericytoma. Despite fifty-four Gy of local irradiation subsequently being performed for cervical lesion to prevent tumor recurrence, multiple metastases have been revealed twenty-five months after the surgery. Careful and long follow up for hemangiopericytoma is essential even after gross total surgical removal and postoperative radiotherapy.

We previously discovered the correlation between light-induced chromophore color change of a photo-receptor membrane protein bacteriorhodopsin (bR) and its two-dimensional crystalline state in the membrane. To apply this phenomenon to a novel optical memory device, it is necessary that bR molecules are immobilized as maintaining their structure and functional properties. In this work, a poly(vinyl alcohol) (PVA) hydrogel with physical cross-linkages (hydrogen bonds between PVA chains) that resulted from repeated freezing-and-thawing (FT) cycles was used as an immobilization medium. To investigate the effects of physically cross-linked PVA gelation on the structure and function of bR in purple membranes (PMs), spectroscopic techniques were employed against PM/PVA immobilized samples prepared with different FT cycle numbers. Visible circular dichroism spectroscopy strongly suggested PM stacking during gelation. X-ray diffraction data also indicated the PM stacking as well as its native-like crystalline latt...