Basal ganglia lesions after MPTP administration in rhesus monkeys.

In monkeys, intracarotid infusion of a single low dose of MPTP reliably induces a hemiparkinsonian syndrome that is stable over time. This model has been widely used to assess novel anti-parkinsonian therapies. Here, we report the exceptional finding of severe necrotic lesions that were observed in the basal ganglia (but not in the substantia nigra) of monkeys that received a single intracarotid injection of MPTP followed by gene therapy treatments. Although extensive unilateral dopaminergic nigrostriatal loss was found in all the animals, partial behavioral recovery was observed in the subjects that presented pallidal necrotic lesions. This report discusses possible causes and effects of the necrotic lesions and their locations and the value of the intracarotid MPTP model. Testing novel therapies in monkey models has become an essential step before clinical trials. These results indicate that evaluation of any treatment should consider possible confounding factors that may affect the results.

The identification of novel therapeutic targets for the treatment of malignant brain tumors.

A two-step strategy was developed consisting of differential display reverse transcriptase polymerase chain reaction (DDRT-PCR) with cultured normal human fetal astrocytes and U-373MG glioma cells followed by reverse Northern analysis of normal brain and primary tumor tissues. hu-dek, alpha-NAC, ribosomal proteins L7a and L35a, and five novel genes were identified. Since none of these genes has been previously shown to be associated with malignant brain tumor formation, this approach may be useful to identify novel targets for the diagnosis and treatment of brain tumors.

Unappreciated agenesis of cerebellum in an adult: case report of a 38-year-old man.

An unexpected finding at autopsy of almost complete agenesis of the cerebellum in an apparently functional, mentally subnormal 38-year-old man who died as the result of an accidental electrocution is reported. The posterior fossa was normal in appearance despite nearly complete absence of the cerebellum. A number of syndromes of cerebellar atrophy or dysgenesis have been reported, but congenital agenesis is considered a very rare condition. It does not resemble most common cerebellar malformations or acquired conditions, especially in an adult, who apparently had reasonable motor and coordinative function. The relevant literature is reviewed.

Epilepsy, vagal nerve stimulation by the NCP system, all-cause mortality, and sudden, unexpected, unexplained death.

PURPOSE: This report concerns the 2-year extension of the study of mortality and sudden, unexpected, unexplained death in epilepsy (SUDEP) in the cohort of patients receiving vagal nerve stimulation by the NCP System for the treatment of epilepsy. METHODS: A cohort of 1,819 individuals was followed 3,176.3 person-years from implantation. The 25 deaths that occurred during NCP System activation were reviewed for SUDEP by a panel. RESULTS: The mortality rates were lower [standardized mortality ratio (SMR = 3.6)] with the extended follow-up compared to the previous finding (SMR = 5.3). The SUDEP rates (4.1 vs. 4.5 per 1,000 person-years) were similar to those in the previous study of this cohort. When the vagal nerve stimulation experience is stratified by duration of use, the rate of SUDEP was 5.5 per 1,000 over the first 2 years, but only 1.7 per 1,000 thereafter. CONCLUSIONS: The mortality and SUDEP rates are similar to those reported from clinical trials of new drugs and cohorts of severe epilepsy. The lower SUDEP rates after 2 years of follow-up are intriguing, but require further investigation.

Beta1,6-N-acetylglucosamine-bearing N-glycans in human gliomas: implications for a role in regulating invasivity.

The metastatic potential of tumor cells has been shown to be correlated with the expression of tri- and tetra-antennary beta1,6-N-acetylglucosamine (beta1,6-GlcNAc)-bearing N-glycans, which are recognized by Phaseolus vulgaris leukoagglutinating lectin (L-PHA). The expression of beta1,6-GlcNAc-bearing N-glycans also has been used as a marker of tumor progression in human breast and colon cancers. In this report, the role of N-glycan branching in regulating glioma migration and invasion was examined. The expression of beta1,6-GlcNAc-bearing N-glycans was found in human glioma specimens, whereas astrocytes from normal adult brain were negative. The expression of N-acetylglucosaminyltransferase V (GnT-V) mRNA, which is responsible for the biosynthesis of beta1,6-GlcNAc-bearing N-glycans, was high in glioma cell lines with robust ets-1 expression. To study the molecular mechanism of GnT-V expression in human glioma cells, an inducible ets-1 gene was stably transfected into SNB-19 cells using a tetracycline repressor system. GnT-V mRNA expression was increased by the induction of c-ets-1, suggesting that the Ets-1 transcription factor directly regulates the transcription of GnT-V. Stable transfection of GnT-V into human glioma U-373 MG cells resulted in changes in cell morphology and focal adhesions and a marked increase in glioma invasivity in vitro. L-PHA has little effect on cell migration. On the contrary, Phaseolus vulgaris erythroagglutinating lectin (E-PHA), which recognizes bisecting beta1,4-GlcNAc-bearing N-glycans, strongly inhibits cell migration (haptotaxis) on a fibronectin substrate in U-373 MG transfectants and other glioma cell lines tested. These results suggest that the increased beta1,6-GlcNAc-bearing N-glycan expression found in malignant gliomas is modulated by GnT-V through the Ets-1 transcription factor, and that the branching of complex type N-glycans plays a major role in glioma invasivity.

Epilepsy, vagal nerve stimulation by the NCP system, mortality, and sudden, unexpected, unexplained death.

PURPOSE: To determine rates of all-cause mortality and of sudden, unexpected, unexplained deaths in epilepsy (SUDEP) in a cohort of individuals treated with the Neuro Cybernetic Prosthesis (NCP) System for intractable epilepsy, and; to contrast the NCP experience with other epilepsy cohorts. METHODS: A cohort of 791 individuals were followed for 1,335 person-years from implantation. Of the total cohort, 120 individuals had their NCP System devices deactivated. The 15 deaths which occurred during NCP System activation were reviewed for SUDEP by a panel. There were three additional deaths and 242.5 person-years of monitoring after deactivation. RESULTS: The standardized mortality ratios for NCP System were 5.3, 95% confidence interval (CI) 3.0-8.7; and for the time period after device deactivation, 4.4, 95% CI 0.9-12.8. Six of the deaths during stimulation were considered definite or probable SUDEP and two as possible SUDEP. Seven were not considered to be SUDEP. The incidence of definite/probable SUDEP was 4.5 per 1,000 person-years and 6.0 per 1,000 person-years for definite/probable/possible SUDEP. CONCLUSIONS: The mortality rates and standardized mortality ratios are comparable with studies of young adults with intractable epilepsy who were not treated with NCP System. These SUDEP rates are not significantly different from those reported in the recent studies of lamotrigine (LTG), gabapentin (GBP), and tiagabine (TGB). The higher rates of SUDEP in the NCP System cohort, as compared with recent drug trials, presumably is explained by the selection of relatively higher-risk patients for the NCP System device.

alpha2,3-sialyltransferase mRNA and alpha2,3-linked glycoprotein sialylation are increased in malignant gliomas.

CMP-NeuAc: Galbeta1,3(4)GlcNAc alpha2,3-sialyltransferase (alpha2,3-ST) mRNA was expressed in human glioma specimens, human fetal astrocytes, and a panel of brain tumor cell lines. Maackia amurensis agglutinin staining revealed the presence of alpha2,3-linked sialic acids on glioma cell surfaces and extracellular matrices whereas normal human adult astrocytes were negative. Increased expression of alpha2,3-linked glycoprotein sialylation may play a role in glial tumorigenesis.

Sudden unexplained death in epilepsy: observations from a large clinical development program.

PURPOSE: The present study was conducted to determine the rate of sudden unexplained death in epilepsy (SUDEP) in a well-defined cohort of patients included in the lamotrigine (LTG) clinical development database. METHODS: A panel of scientists experienced in the area of SUDEP was assembled and provided with case summaries on all deaths (n = 45) reported during the initial clinical development of LTG. The panel developed a set of criteria for classifying cases as SUDEP (definite or highly probable), possible SUDEP, or non-SUDEP. This classification algorithm was then applied to the LTG cases, and SUDEP rates were calculated using patient-years of exposure as the denominator. RESULTS: At the time of the study, 4,700 patients (5,747 patient-years of exposure) were included in the worldwide LTG clinical trials database. In this cohort, 45 deaths were reported. Eighteen were judged by the panel to be SUDEP, 6 were defined as possible SUDEP, 20 were judged to be due to other causes (non-SUDEP), and 1 lacked sufficient data from which to make a classification. The overall SUDEP rate (definite/ highly probable SUDEP and possible SUDEP combined) was calculated to be 3.5 in 1,000 patient-years of exposure to LTG. CONCLUSIONS: The rate of SUDEP in this cohort of patients was comparable to the rate that would be expected in young adults with severe epilepsy (the subgroup of patients believed to be at highest risk of SUDEP). The data suggest that the rate of SUDEP in the LTG clinical development program is a function of the clinical trial population and is unrelated to drug treatment.

Forensic considerations in sudden unexpected death in epilepsy.

Sudden death in epilepsy has recently found its way into both civil and criminal litigation in the United States. Civil cases commonly involve actions or inactions by physicians with respect to antiepileptic drugs (AEDs) alleged to have caused sudden unexpected death in a patient with epilepsy (SUDEP). The context may be discontinuation or change of AEDs or failure to warn of the complication of SUDEP. A common issue in adjudication of such cases is the role of causality of medication type and level in SUDEP. Current knowledge does not permit an accurate assessment of risk for medication discontinuation or poor compliance. Related issues are discussed. In criminal litigation, SUDEP has been accepted by a Federal Court as a cause of death in a crime victim for whom the actions of the accused caused an epileptic state.

The expression of Gal beta 1,4GlcNAc alpha 2,6 sialyltransferase and alpha 2,6-linked sialoglycoconjugates in human brain tumors.

CMP-NeuAc: Gal beta 1,4GlcNAc alpha 2,6 sialyltransferase (alpha 2,6-ST) [EC 2.4.99.1] is developmentally regulated, shows a high degree of tissue specificity, and appears to play a role in oncogenic transformation and metastasis. In the present study, we have performed the first detailed analysis of the expression of alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugates in human brain tumors. We used a polyclonal, monospecific anti-rat alpha 2,6-ST antibody and the alpha 2,6-linked sialic acid-specific lectin, Sambucus nigra agglutinin (SNA) for histochemical studies, and a human alpha 2,6-ST-specific cDNA probe for Northern analysis. Meningiomas, chordomas and craniopharyngiomas frequently expressed alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugates. Among the different meningioma subtypes, meningothelial meningiomas stained more strongly with both anti-alpha 2,6-ST antibody and SNA than the fibroblastic and anaplastic meningiomas. On the other hand, all tumors of glial origin and medulloblastomas were virtually devoid of either alpha 2,6-ST or alpha 2,6-linked sialoglycoconjugate expression. Moreover, very weak to negligible expression of both alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugates was observed in brain metastases. In conclusion, alpha 2,6-ST and alpha 2,6-linked sialoglycoconjugate expression is associated with non-neuroectodermal epithelial-like tumors.

The expression of CMP-NeuAc: Gal beta 1,4GlcNAc alpha 2,6 sialyltransferase [EC 2.4.99.1] and glycoproteins bearing alpha 2,6-linked sialic acids in human brain tumours.

The expression of CMP-NeuAc: Gal beta 1,4GlcNAc alpha 2,6 sialyltransferase (alpha 2,6-ST) [EC 2.4.99.1] and glycoproteins bearing alpha 2,6-linked sialic acids were examined in primary human brain tumours and cell lines. 79% (19/24) of the meningiomas expressed alpha 2,6-ST mRNA, 42% (10/24) of which showed very high expression. alpha 2,6-ST mRNA expression was undetectable in normal brain tissue. In contrast, only 1/13 of the gliomas examined expressed detectable alpha 2,6-ST mRNA. Metastases to the brain did not express measurable amounts of alpha 2,6-ST mRNA. Less expression was found in malignant (i.e. anaplastic) compared to benign (i.e. meningothelial) meningiomas. Two-dimensional SDS-PAGE of glioma and meningioma proteins, followed by Sambucus nigra lectin staining, revealed the presence of a glycoprotein bearing alpha 2,6-linked sialic acids, M(r) = 53 kDa and a pI = 7.0 (MEN-1) that appeared in all seven of the meningiomas examined, but was expressed at barely detectable levels, if at all, in seven out of the seven glioblastomas examined. Thus, decreased alpha 2,6-ST expression may play a role in the aggressive nature of anaplastic meningiomas, but appears to be virtually absent in all tumours of glial origin.

Cohort study of incidence of sudden unexplained death in persons with seizure disorder treated with antiepileptic drugs in Saskatchewan, Canada.

To measure the incidence of sudden unexplained death in treated persons with epilepsy (SUDEP) and to identify risk factors for SUDEP, a cohort of 6,044 persons aged 15-49 years with more than four prescriptions for antiepileptic drugs (AEDs) was identified from the Saskatchewan Health prscription drug file. To exclude subjects whose sudden deaths (SUDs) might be misattributed to another chronic underlying disease, subjects with hospitalizations for cancer or heart problems were excluded. To exclude subjects without epilepsy, subjects with > 2-year AED treatment followed by AED-free time and subjects receiving < 1 U/day were excluded. The final cohort consisted of 3,688 subjects. Follow-up was started at the first AED prescription listed in the prescription drug file and ended at the earliest of the following: age 50 years, death, or last registration in the Saskatchewan Health. For 153 of 163 deaths occurring in the cohort, copies of anonymized death certificates were obtained and copies of anonymized autopsy reports of potential SUDEP cases were examined. There were 18 definite/probable SUDs and 21 possible SUDEPs, yielding a minimum incidence of 0.54 SUDEP per 1,000 person-years and a maximum of 1.35 SUDEP per 1,000 person-years. SUDEP incidence increased with male sex, number of AEDs ever prescribed, and prescription of psychotropic drugs and was highest in males with a history of treatment with three or more AEDs and four or more psychotropic drug prescriptions. Poisson regression showed a 1.7-fold increase in risk of SUDEP for each increment in maximum number of AEDs administered, a likely surrogate for severity and persistence of seizures.

A prospective study on sudden unexpected death in epilepsy.

Sudden unexpected death accounts for a substantial portion of deaths among epileptics. The incidence of this phenomenon is probably 1 in 370 to 1 in 1,110 in the general epileptic population but may be even higher in the 20- to 40-year age group, and still higher if epileptics with symptomatic epilepsy are selected. Sudden unexpected death in epileptics has been observed at least once weekly by the Office of the Medical Examiner of Cook County (Chicago), Illinois, for many years. A year-long prospective study revealed that victims of this complication of epilepsy are most commonly black males averaging 35 years of age who have infrequent generalized seizures and usually have some structural lesion in the brain responsible for their seizures. They tend to abuse alcohol and have poor compliance with anticonvulsant medication. The electroencephalograms display considerable variability from record to record. At autopsy the heart, lung, and liver weights were heavier and the brain weights were lighter than expected. The mechanisms involved in sudden unexpected death in epileptics may include autonomically mediated cardiac arrhythmia alone or in combination with sudden "neurogenic" pulmonary edema and "backward" cardiac failure.

Castleman's disease manifesting in the central nervous system: case report with immunological studies.

Castleman's disease is an uncommon lymphoproliferative disorder that manifests itself as a local or generalized tumor-like condition affecting both lymph nodes and nonnodal tissues, usually in the chest or abdomen. Only two prior examples involving the central nervous system had been reported when this patient was encountered. Very recently, three additional cases have been reported by Severson et al. We report the sixth case of Castleman's disease affecting the central nervous system, which occurred in a 63-year-old woman in whom the diagnosis was made after craniotomy for a mass lesion involving the dura over the frontal regions. Neuroradiological, clinical, and immunopathological characteristics of the case are presented. The lesion was treated with cranial irradiation and the patient is alive and symptom free three years after initial treatment.

Embolization of cotton pledgets following insertion of porcine cardiac valve bioprostheses.

A variety of complications involving heart valve implants have been documented. Embolism originating from thrombosis of the valve has been a recurrent problem in mechanical and to a lesser extent porcine implants. We report two accidental deaths as a result of embolization of cotton pledgets from porcine valves. Hospital personnel failed to remove this cotton material from the valves before surgical placement. In the first case, when portions of the pledgets embolized to both carotid arteries, fatal cerebral infarction occurred. In the second case, portions of the pledgets embolized to a coronary artery producing severe left ventricular failure.

Medulloblastomas in childhood: histological factors influencing patients' outcome.

Sixty-five medulloblastomas in infancy and childhood treated from 1965 through 1981 were reviewed, and the correlation between histological findings of medulloblastomas and clinical course of the patients was studied. Thirty-five patients died but the remaining 30 are alive and without clinical evidence of recurrence 5 years or more after surgery. Certain histological features on light microscopic examinations (e.g., pleomorphism of tumor cells, nuclear-cytoplasmic ratio, mitotic index, degree of vascularity and endothelial proliferation) do influence patient outcome with statistical significance (P less than 0.05). Thirty out of 65 medulloblastomas were examined further, using immunohistochemical methods with glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), and factor VIII/vW factor (F VIII/vWF). GFAP stain was negative in 20%, NSE stain in 13.3% and F VIII/vWF stain in 16.7% of the medulloblastomas studied. "Desmoplastic" medulloblastomas showed a strong tendency toward positive NSE and GFAP staining in the glomerular portion. There was no correlation between patient outcome and the results of applied immunohistochemical studies. Our data indicate that certain histological features may influence patient outcome, but the degree and pattern of cellular differentiation do not predict outcome.

Cerebral astroblastoma: immunohistochemical and ultrastructural features. Case report.

Astroblastoma is a rare glial tumor occurring predominantly in the cerebral hemispheres of young adults. Foci of astroblastoma-like patterns are commonly found in glioblastomas and other malignant glial tumors and cause confusion over the classification of the tumor as an individual entity. However, the existence of astroblastoma in histologically pure form and its typically long history, as compared with the more aggressive gliomas in which it may occur as a pattern, distinguish it as a separate and distinct tumor. A case of pure astroblastoma of the cerebral hemisphere is reported in a 3-year-old child with a 5-year course. The tumor has been resected five times, and its pattern has remained the same in all recurrences. The child is presently alive with some neurological deficit. The immunohistochemical and electron microscopical findings of this tumor are presented, and the historical development of the entity is discussed.

Chronic cerebral herniation in shunted Dandy-Walker malformation.

A review of serial computed tomography (CT) scans of 25 patients with the Dandy-Walker malformation revealed six patients with chronic downward transincisural herniation of the cerebrum after shunt decompression of the posterior fossa cyst or malfunction of a lateral ventricular drainage catheter, or both. Chronic cerebral herniation was detected postmortem in a seventh patient with the Dandy-Walker malformation. The CT findings and autopsy appearance of this previously undescribed feature of shunted Dandy-Walker malformation are illustrated.

Sudden epilepsy deaths and the forensic pathologist.

Sudden unexpected deaths in epileptic persons are not rare events, most commonly encountered by the forensic pathologist rather than the clinician. Such deaths may represent 1-1.5% of all "natural" deaths certified by the medical examiner or coroner. The typical victim is a black male about 30 years of age who tends to abuse alcohol, with a history of generalized epilepsy for more than 1 year and likely for more than 10 years. There are a lack of obvious anatomic causes for the death at autopsy, but 60-70% of cases will have a lesion in the brain (most commonly old trauma) to explain the epilepsy. Most victims have no blood levels of anticonvulsant medications at the time of death. We have evolved a form for use by medical examiner/coroner's investigators at the scene to collect relevant information which will be of assistance to the pathologist in interpreting the case. Estimated prevalence of sudden epilepsy death, mechanisms, and other features of such cases are reviewed briefly.