Yasunobu Itoh

Intramedullary spinal cord germinoma: case report and review of the literature.

We discuss the case of a patient with a recurring intramedullary spinal cord germinoma of the lower thoracic spinal cord, which was successfully excised. A primary intramedullary spinal cord germinoma is very rare, and only four other cases have been reported in the literature. All five cases are reviewed regarding the appearance of the germinomas, their neuroradiological features, and their histopathological findings. We also discuss treatment choices for germinomas of the spinal cord.

Neurotrophic agents in fibrin glue mediate adult dorsal root regeneration into spinal cord.

OBJECTIVE The aim of the present study was to determine whether neurotrophic factors (NTFs) exogenously administered in fibrin glue assisted cut dorsal root axons of adult rats to regenerate into the spinal cord. METHODS Rats received intraspinal implants of fibrin glue containing neurotrophin-3, brain-derived NTF, ciliary NTF, or Dulbeccos modified Eagles medium (control) into left dorsal quadrant cavities aspirated in the lumbar enlargement. The transected L5 dorsal root stump was placed at the bottom of the lesion cavity and was secured between the fibrin glue and the spinal cord. Regenerated dorsal root axons were subsequently labeled with immunohistochemical methods to demonstrate those that contained calcitonin gene-related peptide. RESULTS Calcitonin gene-related peptide-immunoreactive dorsal root axons regenerated across the dorsal root-spinal cord interface of rats with fibrin glue containing neurotrophin-3, brain-derived NTF, or ciliary NTF, entered the spinal cord, and frequently arborized within clusters of motoneuronal cell bodies. Only a few axons regenerated into the spinal cord of animals with fibrin glue implants that lacked NTF, and their growth within the spinal cord was extremely limited. The results of quantitative studies confirmed these observations. CONCLUSION Our results indicate that neurotrophin-3, brain-derived NTF, and ciliary NTF enhance dorsal root regeneration into spinal cord and that fibrin glue is an effective medium for intraspinal delivery of NTF. This method of delivering NTF may therefore provide a strategy for restoring injured spinal reflex arcs.

Novel Dural Closure Technique Using Polyglactin Acid Sheet Prevents Cerebrospinal Fluid Leakage after Spinal Surgery

OBJECTIVE: Extradural or subcutaneous cerebrospinal fluid (CSF) leakage is a common complication after spinal surgery and is associated with the risks of poor wound healing, meningitis, and pseudomeningocele. Numerous methods to prevent postoperative CSF leakage are available, but pressure-tight dural closure remains difficult, especially with synthetic surgical membranes. The efficacy of a novel dural closure technique was assessed by detecting extradural or subcutaneous CSF leakage on magnetic resonance imaging. METHODS: The novel dural closure technique using absorbable polyglactin acid sheet and fibrin glue and the conventional procedure using only fibrin glue were evaluated retrospectively by identifying extradural or subcutaneous CSF leakage on magnetic resonance imaging scans in the acute (2–7 d) and chronic (3–6 mo) postoperative stages after spinal intradural surgery in 53 patients. RESULTS: The incidence of extradural and subcutaneous CSF leakage was significantly lower (P < 0.05) in the acute (20%) and chronic (0%) stages using polyglactin acid sheet and fibrin glue in 15 patients compared with that in the acute (81%) and chronic (24%) stages using only fibrin glue in 38 patients. One patient in the fibrin glue-only group required repair surgery for cutaneous CSF leakage. CONCLUSION: The combination of polyglactin acid sheet and fibrin glue can achieve water-tight closure after spinal intradural surgery and can minimize the risk of intractable postoperative CSF leakage. This simple, economical technique is recommended for dural closure after spinal intradural surgery.

Immunosuppressants promote adult dorsal root regeneration into the spinal cord.

Immunosuppressants promote neurite extension in culture and facilitate regeneration of peripheral nerves in vivo. However, their neurotrophic effects in the CNS have not been well studied. We utilized a rat dorsal root transaction model to examine the effects of cyclosporine A (CsA) and FK 506 on regeneration of the dorsal root into the spinal cord. After surgery, the rats received daily subcutaneous injections of CsA or FK 506. One month after surgery, dorsal root axons were immunohistochemically labeled to evaluate the extent of regeneration into the spinal cord. Dorsal root axons of CsA/FK 506-treated rats frequently entered into the spinal cord and arborized extensively. Administration of immunosuppressants markedly promoted regeneration of dorsal root axons into the spinal cord.

Congenital glioblastoma of the cerebellum with cytofluorometric deoxyribonucleic acid analysis

A case of congenital glioblastoma arising from the cerebellum is presented with special reference to microspectrophotometric deoxyribonucleic acid (DNA) analysis of the tumor cells. Seven cases of this condition are already in the literature. The prognosis is poor and most of the reported cases survive no more than 2 months. Cytofluorophotometric DNA studies were helpful in elucidating the extreme heterogeneous distribution of DNA contents of the tumor cells, suggesting a biological aggressiveness probably related to the rate of proliferation.

β-Tricalcium phosphate promotes bony fusion after anterior cervical discectomy and fusion using titanium cages.

Study Design. Retrospective consecutive cohort study. Objective. To study the effectiveness of &bgr;-tricalcium phosphate (&bgr;-TCP) granules as a packing material in the titanium cages for anterior cervical discectomy and fusion (ACDF), compared with the conventional hydroxyapatite (HA) granules. Summary of Background Data. ACDF using titanium cages is a standard procedure for the treatment of cervical spinal degenerative diseases. Synthetic bone substitutes are widely used to pack the titanium cage to augment intervertebral bony fusion, but the efficacy has not been confirmed. Methods. Fusion condition was evaluated on lateral radiographs and computed tomography. Complete fusion of the treated segments was defined by three criteria: movement of the spinous process at flexion and extension positions of less than 3 mm, bony bridging between vertebral bodies, and absence of the halo around the titanium cage. The evaluation was performed at 6 months, 1 year, and 2 years after surgery. Results. Intervertebral fusion was studied in patients who underwent ACDF using &bgr;-TCP (93 segments of 57 patients) or HA (72 segments of 48 patients) packing of cylindrical titanium cages. Complete fusion rate at 6 months and 1 year was significantly better in the &bgr;-TCP group (46% at 6 months and 69% at 1 year) than in the HA group (24% at 6 months and 49% at 1 year), but the rate was similar at 2 years in the &bgr;-TCP group (94%) and the HA group (90%). There were no material-related adverse effects. Conclusion. Satisfactory final fusion rates were obtained after ACDF using both &bgr;-TCP- and HA-packed titanium cages. &bgr;-TCP showed higher fusion rate in the early stage after surgery and can be recommended as a bone substitute for ACDF with titanium cages.

Intraspinal Implants of Fibrin Glue Containing Glial Cell Line-Derived Neurotrophic Factor Promote Dorsal Root Regeneration into Spinal Cord

Objective: The purpose of this study was to determine whether glial cell line—de rived neurotrophic factor (GDNF) delivered intraspinally via a fibrin glue (FG) en hanced regeneration of cut dorsal root (DR). Methods: FG containing GDNF was inserted into aspiration cavities in the lumbar enlargement of adult rats. The tran sected L5 DR stump was placed at the bottom of the cavity and sandwiched between the FG and the spinal cord. Regenerated DR axons were labeled with horseradish peroxidase (HRP) or with immunohistochemical methods for calcitonin gene-related peptide (CGRP). Results: Primary afferent axons labeled with HRP regenerated into the spinal cord, received GDNF, and made frequent arborization there. Some of these were myelinated axons that established synapses on intraspinal neuronal profiles. CGRP-immunoreactive DR axons extended into the motor neurons and formed promi nent varicosities around their cell bodies. Only a few axons regenerated into the spinal cords given FG without GONE Conclusions: Our results indicate that GDNF en hances regeneration of DR into the adult rat spinal cord and that GDNF may be ef fectively supplied to the intraspinal injury site via FG. Because the regenerated axons establish synapses on intraspinal neurons, this therapeutic strategy has the potential to help to rebuild spinal reflex circuits interrupted by spinal cord injury. Key Words: GDNF—Fibrin glue—Intraspinal injury—Calcitonin gene-related peptide—Dorsal root regeneration—Electron microscopy—Glial cell line-derived neurotrophic fac tor—Horseradish peroxidase.

Spinal cord ependymoma: a positron emission tomographic study with (11C-methyl)-L-methionine.

An intramedullary spinal cord ependymoma was studied by positron emission tomography (PET) using (11C-methyl)-L-methionine (11C-Met). MRI showed a homogeneously enhancing tumour at C6-T2 with cysts at its rostral and caudal ends. Sagittal PET images demonstrated high11C-Met uptake in the solid portion of the tumour, particularly ventrally at C7-T2, where viable tumour cells proliferated in association with abundant perforating vessels. Met-PET would appear useful for delineating the viable protion of intramedullary ependymomas.

Time course of dorsal root axon regeneration into transplants of fetal spinal cord: an electron microscopic study.

Intraspinal transplants of fetal CNS tissue permit or enhance the regeneration of cut central axons of adult dorsal root ganglion (DRG) neurons. Some of these regenerated axons establish synapses with transplant neurons. The aims of the present study were to determine when regenerated DRG axons begin to form synapses with transplanted embryonic spinal cord neurons and whether these synapses are permanent. We also examined the development of transplant neuropil in areas innervated by the regenerated axons. Whole pieces of Embryonic Day 14 spinal cord were introduced into hemisection cavities made at the level of the lumbar enlargement, and the cut L4 or L5 dorsal root was juxtaposed to the transplant. Regenerated DRG axons immunoreactive for calcitonin gene-related peptide (CGRP) were labeled by immunohistochemical methods and examined by electron microscopy from 1 week to 1 year after surgery. CGRP-immunoreactive axon terminals made synaptic contacts with dendrites and perikarya of transplant neurons by 1 week after axotomy. The morphology of the synapses was immature. Large growth cone-like structures were also present at 1 week but not at 2 weeks or later. At 2 weeks, regenerated unmyelinated axons formed terminals similar to those found in animals surviving for 48 weeks. Axoaxonic synapses in which the pre- and postsynaptic elements were immunolabeled for CGRP and regenerated CGRP-labeled myelinated axons were observed at 4 weeks and later. The area of distribution of CGRP staining increased until 12 weeks and the synaptic density of regenerated CGRP-labeled terminals increased for 24 weeks. The results indicate that the synaptic terminals of regenerated primary afferent axons are permanently retained within fetal spinal cord transplants. Transplants may therefore contribute to the permanent restoration of interrupted neural circuits.

Multiple spinal dural arteriovenous fistulas

SummaryMultiple spinal dural arteriovenous fistulas (DAVFs) have been rarely reported and only two such cases are found in the literature. A 71-year-old man complained of muscle weakness and hypesthesia in both legs and angiographically diagnosed as thoracic DAVF. The fistula was surgically treated, however, the symptoms recurred 14 months after the first treatment. Angiography revealed a new fistula in the lumbar region and this was also treated surgically. In the previously reported cases of multiple spinal DAVFs, the second fistulas were also diagnosed after the initial treatment. Symptomatic patients after the initial treatment of DAVF should be re-examined angiographically.