Allogeneic Stem Cell Therapy for Acute Ischemic Stroke: The Phase 2/3 TREASURE Randomized Clinical Trial

Importance

Cell therapy is a promising treatment approach for stroke and other diseases. However, it is unknown whether MultiStem (HLCM051), a bone marrow-derived, allogeneic, multipotent adult progenitor cell product, has the potential to treat ischemic stroke.

Objective

To assess the efficacy and safety of MultiStem when administered within 18 to 36 hours of ischemic stroke onset.

Design, Setting, and Participants

The Treatment Evaluation of Acute Stroke Using Regenerative Cells (TREASURE) multicenter, double-blind, parallel-group, placebo-controlled phase 2/3 randomized clinical trial was conducted at 44 academic and clinical centers in Japan between November 15, 2017, and March 29, 2022. Inclusion criteria were age 20 years or older, presence of acute ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score of 8-20 at baseline), confirmed acute infarction involving the cerebral cortex and measuring more than 2 cm on the major axis (determined with diffusion-weighted magnetic resonance imaging), and a modified Rankin Scale (mRS) score of 0 or 1 before stroke onset. Data analysis was performed between May 9 and August 15, 2022.

Exposure

Patients were randomly assigned to either intravenous MultiStem in 1 single unit of 1.2 billion cells or intravenous placebo within 18 to 36 hours of ischemic stroke onset.

Main Outcomes and Measures

The primary end points were safety and excellent outcome at day 90, measured as a composite of a modified Rankin Scale (mRS) score of 1 or less, a NIHSS score of 1 or less, and a Barthel index score of 95 or greater. The secondary end points were excellent outcome at day 365, mRS score distribution at days 90 and 365, and mRS score of 0 to 1 and 0 to 2 at day 90. Statistical analysis of efficacy was performed using the Cochran-Mantel-Haenszel test.

Results

This study included 206 patients (104 received MultiStem and 102 received placebo). Their mean age was 76.5 (range, 35-95) years, and more than half of patients were men (112 [54.4%]). There were no between-group differences in primary and secondary end points. The proportion of excellent outcomes at day 90 did not differ significantly between the MultiStem and placebo groups (12 [11.5%] vs 10 [9.8%], P = .90; adjusted risk difference, 0.5% [95% CI, -7.3% to 8.3%]). The frequency of adverse events was similar between treatment groups.

Conclusions and Relevance

In this randomized clinical trial, intravenous administration of allogeneic cell therapy within 18 to 36 hours of ischemic stroke onset was safe but did not improve short-term outcomes. Further research is needed to determine whether MultiStem therapy for ischemic stroke has a beneficial effect in patients who meet specific criteria, as indicated by the exploratory analyses in this study.

Trial Registration

ClinicalTrials.gov Identifier: NCT02961504.

MPC-15 CLINICAL FEATURE OF NON-MIDLINE GLIOMA WITH H3F3A GENE MUTATION

Introduction

Diffuse midline glioma (DMG), H3K27-altered, is a CNS WHO grade 4 glioma that usually occurs mainly in the brainstem region in children and also in the thalamus and spinal cord in older children and adults. On the other hand, glioma with histone H3 p. G34R/V mutations in the cerebral hemispheres are defined in a new classification of Diffuse hemispheric glioma, H3G34-mutant (DHG), in the WHO 2021 classification. However, there are some reports of H3K27-altered non-midline gliomas (NDMG) that are not located in the midline, but the differences between these hemispheric tumors with mutations in different regions of histone H3 are unknown. In this study, we report a comparative study of the clinical characteristics between two groups of glioma, H3K27-altered NDMGs and H3G34-mutant DHGs.

Methods

Among 4128 brain tumor specimens collected in the Kansai Network for Molecular Diagnosis of Central Nervous System Tumors, 25 NDMG cases, excluding 93 cases defined as DMG, were included out of 118 cases with mutations in the H3F3A gene. Both 16 H3K27-altered NDMG cases and 9 H3G34-mutant DHG cases were examined for comparison of clinical characteristics.

Results

There were no differences in gender, tumor location, or pathology between NDMG and DHG. The median age was 47.3 years in NDMG and 26.2 years in DHG, and NDMG was significantly older than DHG (p=0.003). The rate of MGMT promoter methylation is no significant difference between 4 cases (25%) in NDMG and 6 cases (66.7%) in DHG (p=0.087). The Kaplan-Meier survival curve showed no significant difference, with a median survival of 495 days for NDMG and 587 days for DHG (p=0.765).

Discussion and Conclusion

We reported on gliomas with H3F3A mutations that occur in the cerebral hemispheres. We compared the clinical characteristics of NDMG with H3K27-altered and DHG with H3G34-mutant, which have similar tumor locations of occurrence.

Non-Ruptured Temporal Lobe Dermoid Cyst Concomitant with Focal Cortical Dysplasia Causing Temporal Lobe Epilepsy-A Case Report and Literature Review

Background: Intracranial dermoid cyst is a rare, benign, nonneoplastic tumor-like lesion that could cause seizures, headache, and hydrocephalus. We hypothesized that the temporal lobe dermoid cyst in combination with other factors were causing the epileptic seizure. Methods: We encountered a 17-year-old girl with anti-seizure medication-resistant epilepsy secondary to dermoid cyst located in the temporal region depicted on magnetic resonance imaging (MRI). She showed neither symptoms of meningitis nor rupture of the cyst according to serial MRI. We hypothesized that temporal lobe dermoid cyst in combination with other factors, such as focal cortical dysplasia (FCD), etc., was causing epileptic seizures in this case. She underwent dermoid cyst removal surgery with resection of the tip of the antero-inferior temporal lobe. Results: Histopathological study showed multiple small intramedullary dermoid cysts in the left antero-inferior temporal lobe in addition to MRI lesions and FCD. Conclusion: A patient with medically intractable epilepsy secondary to left temporal lobe dermoid cyst showed multiple intramedullary dermoid cysts and focal cortical dysplasia that might have interacted to create epileptogenicity. To our knowledge, this is the first case report of dermoid cyst concomitant with FCD.

Experience using mTOR inhibitors for subependymal giant cell astrocytoma in tuberous sclerosis complex at a single facility

BACKGROUND

Subependymal giant cell astrocytoma (SEGA) is occasionally seen in tuberous sclerosis complex (TSC). Two main options are currently available for treating SEGA: surgical resection or pharmacotherapy using mammalian target of rapamycin inhibitors (mTORi). We hypothesized that opportunities for surgical resection of SEGA would have reduced with the advent of mTORi.

METHODS

We retrospectively reviewed the charts of patients treated between August 1979 and July 2020, divided into a pre-mTORi era group (Pre-group) of patients treated before November 2012, and a post-mTORi era group (Post-group) comprising patients treated from November 2012, when mTORi became available in Japan for SEGA. We compared groups in terms of treatment with surgery or mTORi. We also reviewed SEGA size, rate of acute hydrocephalus, recurrence of SEGA, malignant transformation and adverse effects of mTORi.

RESULTS

In total, 120 patients with TSC visited our facility, including 24 patients with SEGA. Surgical resection was significantly more frequent in the Pre-group (6 of 7 patients, 86 %) than in the Post-group (2 of 17 patients, 12 %; p = 0.001). Acute hydrocephalus was seen in 1 patient (4 %), and no patients showed malignant transformation of SEGA. The group treated using mTORi showed significantly smaller SEGA compared with the group treated under a wait-and-see policy (p = 0.012). Adverse effects of pharmacotherapy were identified in seven (64 %; 6 oral ulcers, 1 irregular menstruation) of the 11 patients receiving mTORi.

CONCLUSIONS

The Post-group underwent surgery significantly less often than the Pre-group. Since the treatment option to use mTORi in the treatment of SEGA in TSC became available, opportunities for surgical resection have decreased in our facility.

Neuroendoscopic Surgery with a Combination of Image Detectable Sheath, Intraoperative Computed Tomography Scan, and Navigation System Improves Accuracy and Safety in Minimally Invasive Evacuation of Intracerebral Hematoma: Technical Note

BACKGROUND

Recent studies have confirmed the effectiveness of minimally invasive endoscopic surgery for intracerebral hematoma (ICH). However, improvements are needed because incomplete hematoma removal may offset the surgical benefits of the technique. We describe a technique of neuroendoscopic surgery using an image detectable sheath, intraoperative computed tomography (iCT) scan, and a navigation system.

METHODS

This is a retrospective study of 15 consecutive patients with spontaneous ICH who received neuroendoscopic surgery. During the surgery, a transparent sheath was fastened tightly to the scalp with 3.0 nylon. The patient's head was covered with a sterilized vinyl sheet and subsequent iCT scan visualized the orientation of the endoscopic sheath and the extent of residual hematoma, allowing the surgeon to decide to continue to remove the hematoma or to finish the treatment.

RESULTS

The median hematoma evacuation rate was 93% (interquartile range, 82.2%-95.9%). The Glasgow Coma Scale score of all patients significantly improved at 1 week after the operation (P < 0.05). No complications associated with the procedure were observed.

CONCLUSIONS

The combination of our techniques improves accuracy and safety of minimally invasive surgical evacuation of hematoma. Performing surgery with iCT scan also improves the spatial recognition of surgeons and therefore may be of educational value.

Intracranial Multiple Pseudotumor Due to Immunoglobulin G4-Related Disease without Other Lesions: Case Report and Literature Review

BACKGROUND

Immunoglobulin (Ig)G4-related disease (IgG4-RD) was defined only recently and can be found in many organs. As intracranial lesions, hypophysitis and pachymeningitis are well known, whereas intracranial pseudotumor is unusual. This case involved multiple intracranial pseudotumors without extracranial lesions, mimicking multiple meningioma.

CASE DESCRIPTION

A 72-year-old woman was referred to our hospital with an incidental mass lesion at the craniocervical junction on magnetic resonance imaging (MRI). MRI showed diffuse enhanced extra-axial nodules around the medulla and middle cranial fossa. Surgery was performed for the gradually enlarging tumor. Intraoperative findings showed hard nodules around the vertebral artery. We performed subtotal resection. Neuropathological findings showed diffuse lymphoplasmacytic infiltration with lymphoid follicles. Immunohistochemical studies for IgG4 and IgG showed the histological criteria for IgG4-RD were met. Given the high IgG4 serum level, we diagnosed IgG4-RD. Steroid was administered initially but was then tapered, and nodules have since remained small.

CONCLUSIONS

This case demonstrates IgG4-RD mimicking meningioma with multiple masses but without extracranial lesions. This case and previous descriptions suggest the possibility of pseudotumor due to IgG4-RD in the presence of multiple extra-axial lesions at the dura and supplying artery, hard nodules with thickening of the artery, and frozen section findings of lymphoplasmacytes surrounded by rich collagen fibers. In such cases, the pseudotumor due to IgG4-RD should be resected, and total resection might not be warranted.

A Potential New Risk Factor for Stroke: Streptococcus Mutans With Collagen-Binding Protein

BACKGROUND

Among human oral bacteria, particular kinds of Streptococcus mutans (SM) known as dental caries pathogens contain a collagen-binding protein, Cnm, and show platelet aggregation inhibition and matrix metalloproteinase-9 activation. We have previously reported that these strains may be a risk factor for intracerebral hemorrhage. As a major sample-providing hospital, we report the clinical details, including intracranial aneurysms and ischemic stroke.

METHODS

After the study received approval from the Ethical Committee, 429 samples of whole saliva were obtained from patients who were admitted to or visited our hospital between February 16, 2010, and February 28, 2011. The study cohort comprised 48 patients with cardioembolic stroke (CES), 151 with non-CES infarct, 54 with intracerebral hemorrhage (ICH), 43 with ruptured intracranial aneurysm (RIA), and 97 with unruptured intracranial aneurysm (UIA). Cultured SM was identified as Cnm-positive when the corresponding gene was positive. The results were compared with those from 79 healthy volunteers. Relationships between Cnm-positive SM and known risk factors, including hypertension, diabetes, hyperlipidemia, smoking, and alcohol consumption, were analyzed.

RESULTS

A statistically significant high Cnm-positive rate was observed in patients with CES, non-CES infarct, ICH, and RIA (P = 0.002, 0.039, 0.013, and 0.009, respectively). There were no relationships between Cnm-positive SM and known risk factors.

CONCLUSIONS

Specific types of oral SM can be a risk factor for cardioembolic infarct, intracerebral hemorrhage, and intracranial aneurysm rupture. Further study is needed.

Primary intraorbital ectopic meningioma

We report a case of intraorbital meningioma. Operative findings and histopathological examination revealed the tumoc to be meningothelial meningloma and to be located entirely outside the optic dura. This case demonstrates the occurrence of primary intraorbital ectopic meningioma, and the tumor was removed through a modified Dolenc approach. The primary intraorbital ectopic meningioma is discussed and the surgical approach to the orbital apex region is reviewed.

Synovial chondromatosis of the temporomandibular joint with intracranial extension

A 52-year-old man presented with an extremely rare case of synovial chondromatosis in the temporomandibular joint (TMJ) with extension into the middle cranial fossa manifesting as swelling and exacerbation of pain. He had a long history of right TMJ disorders. Computed tomography and magnetic resonance imaging showed a mass in the right TMJ with extension into the intracranial part through the destroyed temporal skull base. The preoperative diagnosis was chondrosarcoma or osteosarcoma. The patient underwent surgery via combined trans-zygomatic temporal skull base and pre-auricular approaches and the mass was totally removed. Histological examination found an enormous number of closely packed loose bodies of various sizes, consisting of hyaline chondrocytes. The histological diagnosis was synovial chondromatosis. This rare lesion is difficult to discriminate from chondrosarcoma, so total removal is essential for correct diagnosis and cure.

Chordoid glioma of the third ventricle: a report of two cases, one with ultrastructural findings

Chordoid glioma, which generally occurs in adults, is a rare CNS tumor arising in the anterior part of the third ventricle. We report two cases of chordoid glioma of the third ventricle in a 42-year-old woman and a 51-year-old man, respectively. Both tumors showed essentially the same histological and immunohistochemical features; the tumors were composed of cords and nests of epithelioid, GFAP-immunoreactive cells in a mucinous stroma with lymphoplasmacytic infiltrates at the tumor periphery. Ultrastructural examination in one case revealed that the tumor cells were characterized by the presence of hemidesmosomes and associated focal basal lamina formation, intermediate junctions, microvilli and cilia, and intercellular microrosettes with microvilli. Of interest was that small blood vessels with fenestrated endothelial cells were present in the stroma. In the brain, the presence of fenestrated endothelial cells is a feature of the circumventricular organs (except the subcommissural organ), among which the organum vasculosum of the lamina terminalis is located in the anterior part of the third ventricular floor that is lined by specialized ependymal cells known as tanycytes. These findings further strengthen the hypothesis that chordoid glioma may represent a peculiar clinicopathological subtype of ependymoma (chordoid ependymoma) originating from the lamina terminalis area.

Frontal Anaplastic Oligodendroglioma Showing Multi-organ Metastases After a Long Clinical Course-Case Report-

A 17-year-old woman presented with an anaplastic oligodendroglioma manifesting as generalized seizure. Neuroimaging studies revealed a right frontal tumor. Histological examinations of biopsy specimens revealed that the tumor was oligodendroglial in nature. Total resection was repeated four times, and malignant change was evident within the tissues. The final diagnosis was anaplastic oligodendroglioma. Despite irradiation, combination chemotherapy, and interstitial hyperthermia, the tumor grew rapidly but was confined to the cavity created by previous removal operations. She suffered bone pain in the last 3 months of her life, when neuroimaging examinations disclosed multiple bone lesions. She died at the age of 29 years. At autopsy, generalized metastases from the tumor were identified at various sites, including the dura mater covering the frontal lobes and thoracic cord, cavernous sinus, tuberculum sellae, spleen, liver, pancreas, lungs, paratracheal lymph nodes, vertebral bodies, ribs, sternum, pelvis, dorsal root ganglia, and iliopsoas muscle. This rare case of cerebral anaplastic oligodendroglioma developed in adolescence, and rapid hematogenous spread of the glioma cells into the systemic organs occurred after a relatively long clinical course.

Monitoring of Singlet Oxygen Is Useful for Predicting the Photodynamic Effects in the Treatment for Experimental Glioma

PURPOSE

Singlet oxygen ((1)O(2)) generated in photodynamic therapy (PDT) plays a very important role in killing tumor cells. Using a new near-IR photomultiplier tube system, we monitored the real-time production of (1)O(2) during PDT and thus investigated the relationship between the (1)O(2) production and photodynamic effects.

EXPERIMENTAL DESIGN

We did PDT in 9L gliosarcoma cells in vitro and in an experimental tumor model in vivo using 5-aminolevulinic acid and nanosecond-pulsed dye laser. During this time, we monitored (1)O(2) using this system. Moreover, based on the (1)O(2) monitoring, we set the different conditions of laser exposure and investigated whether they could affect the tumor cell death.

RESULTS

We could observe the temporal changes of (1)O(2) production during PDT in detail. At a low fluence rate the (1)O(2) signal gradually decreased with a low peak, whereas at a high fluence rate it decreased immediately with a high peak. Consequently, the cumulative (1)O(2) at a low fluence rate was higher, which thus induced a strong photodynamic effect. The proportion of apoptosis to necrosis might therefore be dependent on the peak and duration of the (1)O(2) signal. A low fluence rate tended to induce apoptotic change, whereas a high fluence rate tended to induce necrotic change.

CONCLUSIONS

The results of this study suggested that the monitoring of (1)O(2) enables us to predict the photodynamic effect, allowing us to select the optimal laser conditions for each patient.

Selective accumulation and strong photodynamic effects of a new photosensitizer, ATX-S10.Na (II), in experimental malignant glioma

We investigated the feasibility of a novel photosensitizer, ATX-S10.Na (II), in photodynamic therapy (PDT) for glioma. First, PDT was performed in various brain tumor cell lines in vitro. Cytotoxicity depended upon both drug concentration and laser energy and the 50% inhibitory concentration ranged from 3.5 to 20 microg/ml. Next, PDT was performed in the subcutaneous and intracranial 9L tumor models in Fischer rats using ATX-S10.Na (II) and light from a 670-nm diode laser delivered by intratumoral insertion of an optical fiber. The effect of PDT on brain tumors was evaluated using magnetic resonance imaging. Sequential changes of the ATX-S10.Na (II) concentrations were also measured quantitatively by fluorospectrometry up to 12 h after intravenous administration in rats with intracranial and subcutaneous tumors. The concentration of ATX-S10.Na (II) in the brain tumor reached a maximum at 2 h after administration and the tumor/normal brain concentration ratio was as high as 131 at 8 h. Intratumoral PDT for intracranial tumors irradiated at this timing showed an obvious anti-tumor effect without severe side effects. The present study demonstrated the highly selective accumulation of ATX-S10.Na (II) in tumor tissue and its potent photodynamic effect in an experimental malignant glioma model.

Cerebral lipoma and the underlying cortex of the temporal lobe: pathological features associated with the malformation

Intracranial lipomas are believed to be congenital malformations rather than true neoplasms, resulting from the abnormal differentiation of the meninx primitiva, the undifferentiated mesenchyme. We report here the surgical pathological features of a lipoma that was located on the cerebral surface of an abnormally formed fissure, and the underlying cortex of the middle temporal gyrus of a 20-year-old woman. The mass was composed of typical adipose tissue in which a large number of blood vessels were present. Thick connective tissue associated with the arachnoid membrane covered the cortical surface. The cortex exhibited a polymicrogyric configuration in which the cortical ribbon was abnormally undulated and excessively folded. Reelin-immunolabeled Cajal-Retzius-cell-like cells were observed frequently in the fused molecular layer. The cortical lamination underlying the molecular layer was poorly defined. Along the border between the connective tissue and cortical surface, there was a narrow zone in which the mesenchymal and neuronal tissues were intermingled, and where immunohistochemical and ultrastructural investigations disclosed disruption of the basal lamina, prominent astrocytosis, and abundant axonal and synaptic profiles. These findings suggest that focal disturbances in cerebral cortical development occur in association with the development of lipomas.

Sharing of polyglutamine localization by the neuronal nucleus and cytoplasm in CAG-repeat diseases

The expansion of a trinucleotide cytosine adenine and guanine (CAG) repeat that codes for polyglutamine is a common gene mutation in the family of hereditary neurodegenerative diseases that includes Machado-Joseph disease (MJD) and dentatorubral-pallidoluysian atrophy (DRPLA). The presence of ubiquitinated neuronal intranuclear inclusions (NIIs) has been recognized as a neuropathological hallmark of these diseases, although the significance of NIIs in the pathogenesis remains a matter of controversy. In a previous study of DRPLA, we proposed that intranuclear diffuse accumulation of mutant proteins is another pathological characteristic of neurones, and that the variable prevalence of this characteristic may be relevant to the variation of clinical symptoms in patients with different repeat sizes. Recently, we also disclosed that polyglutamine tracts are localized in a subset of lysosomes in affected neurones. The present immunohistochemical study of autopsied MJD and DRPLA brains shows that the nucleus and cytoplasm of affected neurones share the subcellular distribution of expanded polyglutamine tracts, the pattern of distribution being specific to each diseased brain. The results suggest that in CAG-repeat diseases, mutant proteins are involved in both the ubiquitin/proteasome and endosomal/lysosomal pathways for protein degradation in different intraneuronal compartments, where their accumulation may exert distinct influences on neuronal physiology.

Autopsy findings of a craniopharyngioma with a natural course over 60 years

BACKGROUND

We report the histologic manifestations in an autopsy case of craniopharyngioma with an unusually long treatment-free course.

CASE DESCRIPTION

A 72-year-old woman with craniopharyngioma, in whom ateliosis due to the suprasellar tumor had been identified at the age of 10 years but had not been treated, was studied postmortem. She had not acquired secondary sex characteristics. At autopsy, a hard mass 2 cm in diameter was present in the suprasellar region and invaded the anterior floor of the third ventricle. Histologically, a large proportion of the mass was replaced by wet keratin, ossified tissue, dystrophic calcification, and fatty adipose tissue: these features indicate widespread degeneration of the tumor cells. Only a few residual cell nests of craniopharyngioma-composed of squamous cells lined with a single columnar cell layer-were observed at the peripheral portion of the mass. Conspicuous reactive astrocytosis with relatively high cellularity was evident in the brain tissue adjacent to the mass.

CONCLUSION

This case may represent a rare example of craniopharyngioma lacking spontaneous growth activity and consequently showing marked degeneration of the tumor cells.

A fourth ventricle atypical teratoid/rhabdoid tumor in an infant

Atypical teratoid/rhabdoid tumor (AT/RT), a recently established central nervous system tumor entity, occurs in children and is more malignant than medulloblastoma/primitive neuroectodermal tumors (PNET). We report here a case of AT/RT in a male infant who was 9 months old at the time of diagnosis. Magnetic resonance imaging revealed that the tumor occupied the fourth ventricle, and at surgery it was found to adhere to the floor of the fourth ventricle. After subtotal removal of the tumor mass, chemotherapy and radiotherapy were performed, but the patient died about 8 months after the diagnosis following rapid regrowth of the residual tumor. Light-microscopically, the tumor was composed mainly of nests of rhabdoid cells with fields of PNET. Occasional mesenchymal and epithelial fields were also evident. Immunohistochemically, these rhabdoid cells were positive for vimentin, epithelial membrane antigen, smooth-muscle actin, cytokeratin, and S-100 protein, and less frequently for glial fibrillary acidic protein. Electron-microscopically, the typical rhabdoid cells contained whorled bundles of intermediate filaments in their cytoplasm. Occasionally, such rhabdoid cells were covered partially by basal lamina at their stromal interface. These findings are typical of AT/RT. Although it is well known that AT/RT often arises in the posterior fossa, detailed reports of cases affecting the fourth ventricle are rare. In this case, the ultrastructural relationship between rhabdoid cells and the basal lamina, which has not so far been described in AT/RT, was of great interest when the nature of the rhabdoid cells was considered.

SCA17 homozygote showing Huntington's disease-like phenotype

We report a homozygous case of spinocerebellar ataxia type 17 with 48 glutamines. The age of the patient at disease onset was not lower than those of heterozygotes with the same CAG-repeat sizes, but the clinical manifestations were rapidly progressive dementia and chorea. Neuronal loss was relatively restricted and most prominent in the Purkinje cell layer and striatum; however, intranuclear neuronal polyglutamine accumulation was widespread, with a high frequency in the cerebral cortex and striatum.

Disruption of postnatal progenitor migration and consequent abnormal pattern of glial distribution in the cerebrum following administration of methylmercury

Transplacental administration of methylmercury (MeHg) induces disruption of neuronal migration in the developing cerebral cortex. However, the effects of MeHg on glial progenitor migration remain unclear. To understand this, we performed double administration of MeHg and 5-bromo-2-deoxyuridine (BrdU) to neonatal rat pups on postnatal day 2 (P2), when glial cells are generated from progenitors in the subventricular zone (SVZ). Histopathological examination of a proportion of the MeHg-treated rats on P28 revealed no apparent abnormalities of cytoarchitecture or neuron count in either the primary motor or primary somatosensory cortex of the cerebrum. BrdU immunohistochemistry revealed abnormal accumulation of the labeled cells in the deeper layers of the cortices and underlying white matter of both areas, where an excessive number of astrocytes (glial fibrillary acidic protein- or S-100beta-immunolabeled cells) and oligodendrocytes (2',3'-cyclic-nucleotide 3'-phosphohydrolase-labeled cells) were located. Next, to investigate the migration of individual progenitors from the forebrain SVZ of P2 neonates, we labeled them in vivo with a retrovirus encoding green fluorescent protein (GFP), following administration of MeHg, and then examined the distribution pattern of the GFP-labeled cells in the P28 cerebrum. We found that the labeled cells developed into astrocytes and oligodendrocytes and were accumulated abnormally in the lateral white matter as well as in the adjacent deeper layer of the lateral cortex and lateral side of the striatum. Thus, exposure to MeHg in the gliogenic period induced irregular distribution of glia as a consequence of abnormal migration of the postnatal progenitors.

Mesenchymal chondrosarcoma of the sellar region

BACKGROUND

It is known that, although rare, mesenchymal chondrosarcoma can originate intracranially. However, no such malignant tumour has been described in the sellar region.

CLINICAL PRESENTATION

We report a case of mesenchymal chondrosarcoma in a 21-year-old man who presented with double vision, right blepharoptosis and facial pain. Upon initial admission, no endocrinological abnormalities were found, and computed tomography and magnetic resonance imaging revealed a mass with calcification in the sella and right cavernous sinus.

INTERVENTION

For this malignant tumour, three surgical resections, two sessions of gamma-knife radiosurgery, one session of fractional irradiation, and one cycle of chemotherapy were performed, resulting in only brief arrest of the tumour growth. Pathologically, the tumour consisted of undifferentiated small cells of high cellularity, and islands of hyaline cartilage. The undifferentiated small cells showed immunoreactivity for vimentin and ultrastructural features suggesting a mesenchymal origin. Lacunar cells in the islands were immunopositive for S-100 protein and vimentin.

CONCLUSION

Although malignant tumours in the sellar region are rare, they should be considered in the differential diagnosis of various sellar tumours typified by non-functioning pituitary adenoma, and mesenchymal chondrosarcoma is one possible candidate.

Neuronal migration disturbance and consequent cytoarchitecture in the cerebral cortex following transplacental administration of methylmercury

To understand the effects of methylmercury (MeHg) on neuronal migration in the developing cerebral cortex, we performed double administrations of MeHg and 5-bromo-2-deoxyuridine (BrdU) to pregnant rats on different embryonic days (E11, E13, E16 or E21). Histopathological examination of a proportion of the offspring on postnatal day 28 revealed no apparent cytoarchitectural abnormalities in the primary motor and primary somatosensory cortices of the cerebrum. Morphometric analysis revealed no significant differences in total neuron population in either of these areas, and no differences in subpopulations of cells in any of the cortical layers, between any of the MeHg-exposed groups and the control animals. However, BrdU immunohistochemistry revealed an abnormally widespread distribution of the labeled cells throughout cortical layers II-VI of offspring exposed to MeHg on E16 and E21, indicating disruption of the inside-out pattern of neuronal migration. We examined one aspect of cell-fate determination by applying immunohistochemistry with antibodies against calbindin, parvalbumin, calretinin, and gamma-aminobutyric acid, but found no differences in the topographic distributions of the antibody-labeled cells in the cortex between the controls and the MeHg-exposed offspring. These results suggest that it is the extrinsic circumstances - rather than the timing of neuron generation - that regulates the expression of these proteins.

Hemifacial spasm associated with an ependymal cyst in the cerebellopontine angle. Case report

No previous case of hemifacial spasm associated with an ependymal cyst has been reported in the literature. In this article the authors report the first case in which hemifacial spasm accompanied an ipsilateral cerebellopontine angle ependymal cyst in a 27-year-old woman. Cyst fenestration and arterial decompression of the facial nerve at the root exit zone resulted in complete resolution of the patient's symptoms. A histopathological study including immunohistochemical methods identified an ependymal cyst.

Alpha-synuclein immunoreactivity in normal and neoplastic Schwann cells

Alpha-synuclein is known to play an important role in several neurodegenerative diseases. Moreover, it is expressed in central nervous system neuronal tumors, and another member of the synuclein family, gamma-synuclein, is overexpressed in breast and ovarian carcinomas. However, the expression of alpha-synuclein has not been reported hitherto in the peripheral nervous system (PNS). In the present study, we investigated normal PNS tissue and schwannomas in human postmortem and biopsy samples using both immunocytochemistry and immunoelectron microscopy with antibodies against alpha-, beta- and gamma-synuclein. In normal PNS tissue, Schwann cells, but not axons or myelin, were immunopositive for alpha-synuclein. In schwannomas, almost all of the tumor cells showed diffuse cytoplasmic staining for alpha-synuclein (30 cases). Ultrastructurally, alpha-synuclein immunoreactivity was found in the cytoplasm of normal and neoplastic Schwann cells, in association with the plasma membrane, ribosomes, rough endoplasmic reticulum, small vesicles, Golgi apparatus and the nuclear outer membrane. No beta- or gamma-synuclein immunoreactivity was found in those cells. These results indicate that in the PNS, alpha-synuclein is a useful marker of Schwann cells and that it is not involved in tumorigenesis.

Diagnostic and surgical strategies for intractable spontaneous intracranial hypotension. Case report

The authors present the case of a 55-year-old man suffering from intractable spontaneous intracranial hypotension, in whom conservative treatment with 19 weeks of bed rest was not effective. In this period the patient twice underwent surgery for bilateral chronic subdural hematoma, a complication of spontaneous intracranial hypotension. Conventional radionuclide cisternography, magnetic resonance imaging, and computerized tomography myelography did not demonstrate cerebrospinal fluid (CSF) leakage. Repeated radionuclide cisternography with the patient in an upright position revealed leakage of the tracer at upper cervical levels. Computerized tomography myelography with breath holding also showed CSF leakage of the contrast medium bilaterally at upper cervical levels. The patient underwent surgery, and bilateral C-2 and C-3 spinal nerve root pouches were sealed off from the subarachnoid space with oxidized cellulose cotton and fibrin glue. Epiarachnoid spaces around the root sleeves were also sealed to ensure complete resolution of the CSF leakage. After the surgery, the patient was completely free of the disease. In the case of intractable persistent spontaneous intracranial hypotension, surgical treatment is preferable to long-term conservative management. To identify CSF leakage, radionuclide cisternography with the patient in the upright position is useful. When obvious leakage is encountered, surgical sealing of the lesion should be performed via a subarachnoid approach.