Limits of the surgically induced model of myelomeningocele in the fetal sheep

PURPOSE

The prevention of Chiari type II malformation (CM) is commonly used as a primary outcome for the evaluation of techniques of fetal myelomeningocele (MMC) surgery in the fetal lamb. The aim of our study was to investigate the frequency of the associated CM in the MMC fetal sheep model and to investigate the contribution of prenatal ultrasound evaluation of CM at the time of prenatal repair.

METHODS

A MMC-like lesion was surgically created at 75 days of gestation in 21 fetuses performing a L1-L5 laminectomy followed by an excision of the exposed dura and a midline myelotomy. At a 90-day gestation, among the 19 alived fetuses, a conventional repair of the MMC-like lesion was performed in seven, four of whom underwent cerebral ultrasound (US) examination before the repair. Twelve fetuses remained untreated (control group). All fetuses underwent post-mortem examination (PM) at 138 days.

RESULTS

At a 90-day gestation, CM was demonstrated by US examination in all four evaluated fetuses. At birth, CM was found in 3/6 control whether CM was absent in all alived fetuses in the prenatal repair group (n = 4).

CONCLUSIONS

Creation of a MMC-like lesion with an additional myelotomy does not always lead to hindbrain herniation. Our study suggests that CM should be assessed by ultrasound examination at the time of the prenatal repair to demonstrate the effectiveness of new techniques for the prenatal repair of MMC.

Prenatal abnormal features of the fourth ventricle in Joubert syndrome and related disorders

Joubert syndrome and related disorders (JSRD) are characterized by absence or underdevelopment of the cerebellar vermis and a malformed brainstem. This family of disorders is a member of an emerging class of diseases called ciliopathies. We describe the abnormal features of the brain, particularly the fourth ventricle, in seven fetuses affected by JSRD. In three cases abnormality of the fourth ventricle was isolated and in four cases there were associated malformations. The molar tooth sign (MTS) was always present and visible on two-dimensional ultrasound and, when performed, on three-dimensional ultrasound and magnetic resonance imaging. The fourth ventricle was always abnormal, in both axial and sagittal views, presenting pathognomonic deformities. It is important to identify JSRD, preferably prenatally or at least postnatally, due to its high risk of recurrence of about 25%. A detailed prenatal assessment of the fourth ventricle in several views may help to achieve this goal.

[Prenatal repair of myelomeningocele: State of the art]

Myelomeningocele is characterized by the extrusion of the spinal cord into a sac filled with cerebrospinal fluid. One part of the postnatal disabilities could be related to the spinal damage and to the cerebral repercussion of the leak of cerebrospinal fluid from the defect. Several experimental studies in animals have demonstrated that a surgical repair of the lesion at middle gestation reduced the postnatal disabilities. These results were confirmed in humans by the Management of Myelomeningocele (MOM) Trial. However, the prenatal surgical repair is associated with maternal and fetal morbidity.

Fetal tumors of the choroid plexus: is differential diagnosis between papilloma and carcinoma possible?

Fetal choroid plexus tumors are uncommon. The prognosis is widely variable and depends on the histological findings: papilloma or carcinoma. We report a case of prenatal diagnosis of choroid plexus mass detected by ultrasound at 33 weeks of gestation. Prenatal (T1, T2, T2* and diffusion weighted sequences) magnetic resonance imaging (MRI) was used to rule out a hematoma. Follow-up examination by ultrasound and MRI revealed a significant increase in the volume of the mass, suggesting a diagnosis of malignant tumor. A healthy neonate was delivered by Cesarean section at 38 weeks of gestation. Full surgical excision of the tumor was performed at 20 days after delivery and histological analysis revealed a papilloma.

[Venous infarction of the neonate]

PURPOSE

To determine the imaging features of hemorrhagic infarction in neonates.

PATIENTS AND METHODS

Retrospective study (1998-2008) of 19 children (17 premature and 2 term deliveries) with early lobar hyperechogenicity on transfontanel US (TFUS). Group I: 11 born infants with clinical as well as TFUS and MRI follow-up. Group II: 8 premature infants deceased within a week from multisystem pathology, with neuropathological study available in 3 cases.

RESULTS

Group I (n=11): periventricular hyperechogenicity in a frontal (7), frontoparietal (2), parietooccipital (1) and temporoparietal (1) distribution with developing cavitary change (n=6). MRI showed a cortex sparing intraparenchymal hematoma. Group II (n=8): periventricular hyperechogenicity in a frontal (4), frontoparietal or parietal (3) and occipital (1) with developing cavitary change (3). Neuropathological examination showed characteristic lesions of venous hemorrhagic infarction. Clinical outcome was generally favorable for the surviving infants with contralateral motor deficit (n=5) non-correlated to the extent of the initial lesions.

CONCLUSION

Venous hemorrhagic infarction mainly affetcs premature infants and typically involves the periventricular frontal white matter. Prognosis is generally favorable. It is thus important to differentiate this entity from asymmetrical cystic periventricular leukomalacia with much different prognosis.

Mycobacterium chelonae infection under adalimumab therapy for spondylarthritis

Tumour necrosis factor (TNF)-alpha antagonists have been prescribed increasingly over the past few years to manage various inflammatory diseases. This widespread use was quickly followed by the heightened frequency of opportunistic mycobacterial infections including environmental non-tuberculous mycobacterial infections (ENTM). We describe a 66-year-old man taking adalimumab for spondyloarthropathy who developed an inflammatory infiltration in his right index finger. A non-necrotising granuloma with epitheloid and giant cells in the dermis and eosinophilic acid-fast bacilli, identified by using Ziehl-Neelsen staining suggested a mycobacterial infection. Cultures for mycobacteria grew positive on Loewenstein-Jensen medium and molecular identification confirmed M. chelonae infection. The outcome was favourable after five months of clarythromycin. In this context of more frequent ENTM infections, chronic non-specific cutaneous lesions of the extremities should evoke systematically cutaneous ENTM infections. Skin biopsy with histological examination and oriented microbiological cultures and molecular identification are mandatory to confirm the diagnosis.

Refining the clinicopathological pattern of cerebral proliferative glomeruloid vasculopathy (Fowler syndrome): report of 16 fetal cases

Cerebral proliferative glomeruloid vasculopathy (PGV) is a severe disorder of brain angiogenesis, resulting in abnormally thickened and aberrant perforating vessels, forming glomeruloids with inclusion-bearing endothelial cells. This peculiar vascular malformation was delineated by Fowler in 1972 as a stereotyped lethal fetal phenotype associating hydranencephaly-hydrocephaly with limb deformities, called Fowler syndrome (FS) or "proliferative vasculopathy and hydranencephaly-hydrocephaly" or "encephaloclastic proliferative vasculopathy" (OMIM#225790). In PGV, the disruptive impact of vascular malformation on the developing central nervous system (CNS) is now well admitted. However, molecular mechanisms of abnormal angiogenesis involving the CNS vasculature exclusively remain unknown, as no genes have been localized nor identified to date. We observed the pathognomonic FS vascular malformation in 16 fetuses, born to eight families, four consanguineous and four non-consanguineous. A diffuse form of PGV affecting the entire CNS and resulting in classical FS in 14 cases, can be contrasted to two cases with focal forms, confined to restricted territories of the CNS. Interestingly in PGV, immunohistological response to a marker of pericytes (SMA, Smooth in PGV Muscle Actin), was drastically reduced as compared to a match control. Our studies has expanded the description of FS to additional phenotypes, that could be called Fowler-like syndromes and suggest that the pathogenesis of PGV may be related to abnormal pericyte-dependent remodelling of the CNS vasculature, during CNS angiogenesis. Gene identification will determine the molecular basis of PGV and will help to know whether the Fowler-like phenotypes are due to the same underlying molecular mechanisms.

Contribution of diffusion-weighted imaging in the evaluation of diffuse white matter ischemic lesions in fetuses: correlations with fetopathologic findings

BACKGROUND AND PURPOSE

The sensitivity of fetal MR imaging is poor with regard to the evaluation of diffuse ischemic white matter (WM) abnormalities. Our purpose was to evaluate the contribution of diffusion-weighted imaging (DWI) in the analysis of microstructural changes in WM and to correlate neuroimaging with neurofetopathologic findings.

MATERIALS AND METHODS

We included fetuses with MR imaging, DWI, and a fetopathologic examination. In a region of interest defined by MR imaging, where T1 and T2 intensities were abnormal, the apparent diffusion coefficient (ADC) was measured and immunohistochemical analysis was performed. In fetuses with no WM abnormality in signal intensity, region of interest was defined at random. Histologic reading was performed with a complete blinding of the MR imaging results and ADC values. Three degrees of histologic appearance were defined with regard to vasogenic edema, astrogliosis, microgliosis, neuronal and oligodendrocytic abnormalities, and proliferation or congestion of vessels and were compared with a chi(2) test in groups A (normal ADC) and B (increased ADC) fetuses.

RESULTS

We included 12 fetuses in group A and 9 in group B, ranging from 29 to 38 weeks of gestation. All group B fetuses and 1 group A fetus demonstrated WM abnormalities in signal intensity. WM edema and astrogliosis were more common in group B than in group A (7/9 vs 2/12 and 8/9 vs 4/12, respectively). No significant difference was observed between both groups with regard to the other parameters.

CONCLUSION

This study showed a strong correlation between increased ADCs and 1) WM abnormalities in signal intensity on MR imaging, and 2) vasogenic edema with astrogliosis of the cerebral parenchyma.

Molecular heterogeneity in fetal forms of type II lissencephaly

Type II lissencephaly (type II LIS) is a group of autosomal recessive congenital muscular dystrophies (CMD) associated with defects in alpha-DG O-glycosylation, which comprises Walker-Warburg syndrome, Fukuyama cerebral and muscular dystrophy, or muscle-eye-brain disease. The most severe forms of these diseases often have a fetal presentation and lead to a pregnancy termination. We report here the first molecular study on fetal type II LIS in a series of 47 fetuses from 41 unrelated families. Sequencing of the different genes known to be involved in alpha-DG O-glycosylation allowed the molecular diagnosis in 22 families: involvement of POMT1 was demonstrated in 32% of cases, whereas POMGNT1 and POMT2 were incriminated in 15% and in 7% of cases, respectively. We found 30 different mutations in these three genes, 25 were described herein for the first time, 15 in POMT1, and five in POMT2 and POMGNT1. Despite sequencing of FKRP, FCMD, and LARGE, no definitive molecular diagnosis could be made for the other half of our cases. Preliminary results concerning genotype-phenotype correlations show that the choice of the first gene sequenced should depend on the clinical severity of the type II LIS; POMT1 and POMT2 for severest clinical picture and POMGNT1 for milder disease. The other genes, FKRP, FCMD, and LARGE, seem not to be implicated in the fetal form of CMD.

Fetal hemangiopericytoma with an associated cerebral anomaly

We report the first case of infantile hemangiopericytoma explored prenatally by fetal ultrasonography and magnetic resonance imaging (MRI). It was associated with a developmental cerebral anomaly identified on MRI. The largest lesions of the multifocal hemangiopericytoma were located in the soft tissue adjacent to the left temporal bone, and smaller lesions were found in the lumbar area and in the retroperitoneum. MRI showed no connection between the tumor and the fetal brain but there was anomalous cerebral gyration in the region and the Sylvian fissure beneath the tumor was enlarged. The pregnancy was terminated because of the severe brain anomalies and postmortem examination confirmed the prenatal findings. Microscopic analysis of the tumor tissue showed branching vessels which are typical of hemangiopericytoma. The lesions in our case occurred in association with macrosomia with visceromegaly detected at autopsy, suggesting a possible role of tumor suppressor genes.

Fetal aqueductal glioneuronal hamartoma: a clinicopathological and physiopathological study of three cases

Fetal hydrocephalus due to aqueductal stenosis is classified into two main groups: congenital (X-linked, atresia, septa and forking) and acquired (post-infectious or post-hemorrhagic, gliosis and tumors).

MATERIAL AND METHODS

We report three fetal cases presenting with severe hydrocephalus, two of which being apparently sporadic, and the third possibly inherited. On macroscopic examination, no associated malformations were identified, either craniofacial dysmorphy, or visceral abnormalities. Neuropathological study revealed massive hydrocephalus caused by narrowing of the Aqueduct of Sylvius. Histological examination evidenced a nodular, well-demarcated mass producing into the aqueductal lumen, and containing numerous immature proliferating glioneuronal cells. Immunohistochemical analyses did not suggest a developmental abnormality of the subcommissural organ but rather a hamartomatous malformative process.

RESULTS

Hamartoma of the posterior fossa has been rarely reported. Post-natal cases have been described in the cerebello-pontine angle or in the quadrigeminal plate, and have always been diagnosed as pilocytic or low-grade astrocytomas. In our cases, the lesions could be related to so-called pencil glioma, sometimes associated with type 1 neurofibromatosis and, to our knowledge, have never been described prior to birth. The occurrence during fetal life and the progressive maturation of the nodules are more likely in favor of a hamartomatous process.

CONCLUSION

Even though they could sporadically occur, an accurate genetic counseling should be required in order to ensure that there is no familial history of Recklinghausen disease, and to provide a more precise evaluation of recurrence risk.

Prenatal detection of ade novo terminal inverted duplication 4p in a fetus with the Wolf-Hirschhorn syndrome phenotype

OBJECTIVES

To present the prenatal diagnosis of a de novo terminal inversion duplication of the short arm of chromosome 4 and a review of the literature.

CASE

An amniocentesis for chromosome analysis was performed at 33 weeks' gestation because ultrasound examination showed a female fetus with multiple abnormalities consisting of severe intrauterine growth retardation, microcephaly, a cleft lip and renal hypoplasia.

RESULTS

Cytogenetic analysis and FISH studies of the cultured amniocytes revealed a de novo terminal inversion duplication of the short arm of chromosome 4 characterized by a duplication of 4p14-p16.1 chromosome region concomitant with a terminal deletion 4p16.1-pter. The karyotype was thus: 46,XX, inv dup del (4)(:p14-->p16.1::p16.1-->qter). The parents opted to terminate the pregnancy. Fetopathological examination showed dysmorphic features and abnormalities consistent with a Wolf-Hirschhorn syndrome (WHS) diagnosis, clinical manifestations of partial 4p trisomy being mild.

CONCLUSION

Although relatively rare, inverted duplications have been reported repeatedly in an increasing number of chromosomes. Only two previous cases with de novo inv dup del (4p) and one with tandem dup 4p have been reported, all of them associated with a 4pter deletion. We report the first case diagnosed prenatally. Breakpoints are variable, resulting in different abnormal phenotype. In our case, clinical manifestations resulted in a WHS phenotype.

Prenatal diagnosis of a small supernumerary, XIST-negative, mosaic ring X chromosome identified by fluorescence in situ hybridization in an abnormal male fetus

Marker or ring X [r(X)] chromosomes of varying size are often found in patients with Turner syndrome. Patients with very small r(X) chromosomes that did not include the X-inactivation locus (XIST) have been described with a more severe phenotype. Small r(X) chromosomes are rare in males and there are only five previous reports of such cases. We report the identification of a small supernumerary X chromosome in an abnormal male fetus. Cytogenetic analysis from chorionic villus sampling was performed because of fetal nuchal translucency thickness and it showed mosaicism 46,XY/47,XY,+r(X)/48,XY,+r(X),+r(X). Fluorescence in situ hybridizations (FISH) showed the marker to be of X-chromosome origin and not to contain the XIST locus. Additional specific probes showed that the r(X) included a euchromatic region in proximal Xq. At 20 weeks gestation, a second ultrasound examination revealed cerebral abnormalities. After genetic counselling, the pregnancy was terminated. The fetus we describe is the first male with a mosaic XIST-negative r(X) chromosome identified at prenatal diagnosis. The phenotype we observed was probably the result of functional disomy of the genes in the r(X) chromosome, secondary to loss of the XIST locus.

Congenital erythropoietic porphyria (Günther's disease): two cases with very early prenatal manifestation and cystic hygroma

Congenital erythropoietic porphyria (CEP) or Günther's disease is the rarest form of the porphyrias. The disease is usually diagnosed at birth or during early infancy, but rarely in utero. We describe here the first two cases of very early prenatal expression of CEP with cystic hygroma diagnosed at 14 weeks in the first fetus and at 19 weeks in the second. Both fetuses presented with severe nonimmune hydrops fetalis as early as 19 and 22 weeks, associated with intrauterine growth retardation, hyperechogenic kidneys and bones. Amniotic fluid was dark brown and uro- and coproporphyrin I was dramatically increased. Molecular screening of the CEP gene detected heterozygous C73R mutation in both fetuses, the other parental mutation being as yet unknown.

The human lumbar anterior epidural space: morphological comparison in adult and fetal specimens

To increase our understanding of the clinical anatomy of the epidural space, the human lumbar anterior epidural space was studied morphologically and developmentally. Histological transverse sections of human lumbar spines were taken at the level of the intervertebral disc and the vertebral body in adult specimens and in fetuses aged 13, 15, 21, 32 and 39 weeks (menstrual age). At 13 weeks, connective tissue filled the epidural space. The dura mater was attached anteriorly to the posterior longitudinal ligament (PLL). The PLL was attached to the vertebral body beside the midline, whereas it adhered to the posterior edge of intervertebral disc. The anterior internal vertebral venous plexus was located anterolaterally and anteromedially. The vertebral canal was lined with connective tissue that differentiated in a periosteum in contact with the ossification centers. At 15 weeks, the PLL was composed of deep and superficial layers. At 21 weeks, the attachment between the dura mater and PLL was ligament-like at the level of the vertebral body. At 32 weeks, the dura mater was adherent to the superficial layer of PLL. At 39 weeks, groups of adipocytes were identified, and the dura mater was attached to the PLL by some ligaments. There were many more similarities between the adult and the 39-week fetus. In conclusion, some differences in the anatomy of the epidural space exist at each fetal stage studied. The structures of the epidural space are already formed in the fetus of 13 weeks, but they differentiate progressively within the connective tissue.

[Prenatal diagnosis of isolated posterior fossa anomalies: attempt at a simplified approach]

The authors suggest, after some embryological, anatomical and nosological reviews, a simplified approach mainly based on the appearance of the pons, cerebellar hemispheres and vermis, independently from an associated cystic dilatation of the posterior fossa. Pontocerebellar hypoplasias and partial or total vermian agenesis are detailed because they can be diagnosed with a prenatal MRI. This classification based on our experience and on the literature data should be of value to evaluate the neurological prognosis.

Prenatal diagnosis of fetal tail and postabortum anatomical description

Fetal ultrasound examination at 13 weeks of gestation demonstrated a homogeneously echogenic protrusion, or tail, 7 mm in length, in the sacral region. At 15 weeks, the ultrasound appearance was consistent with a regression of the tail and by 21 weeks it had completely disappeared. Severe intrauterine growth restriction with reduced uterine blood flow was diagnosed at 21 weeks and intrauterine death occurred at 24 weeks of gestation. Postmortem examination revealed a 4-mm caudal appendage which contained no vertebrae on radiography. The appendage was located under and behind the last sacral vertebra suggesting a true vestigial tail with a delayed process of regression.

[The "smears" technique for the extemporaneous examination: diagnostic contribution to neurosurgical pathology]

Smear preparation is a fairly accurate, simple and reliable tool for rapid intraoperative diagnosis of central nervous system tumors. Compared with frozen sections this technique has the advantage of being both more accurate for cytological details and of requiring less tissue. In addition final histological analysis after direct formalin fixation is of better quality than post freezing fixation. This technique is most helpful in the field of neuro-oncological pathology specially in glial tumors and in stereotactic biopsy procedures. The cytological aspects and smear patterns disclose important complementary diagnostic information for the histopathological examination.

The biochemical pathway of neurofibrillary degeneration in aging and Alzheimer's disease

OBJECTIVE

To determine the spatiotemporal mapping of neurofibrillary degeneration (NFD) in normal aging and the different stages of AD.

BACKGROUND

The pathophysiologic significance of AD lesions, namely amyloid plaques and neurofibrillary tangles, is still unclear, especially their interrelationship and their link with cognitive impairment.

METHODS

The study included 130 patients of various ages and different cognitive statuses, from nondemented control subjects (n = 60, prospective study) to patients with severe definite AD. Paired helical filaments (PHF)-tau and Abeta were used as biochemical and histologic markers of NFD and amyloid plaques, respectively.

RESULTS

NFD with PHF-tau was systematically present in variable amounts in the hippocampal region of nondemented patients age >75 years. When NFD was found in other brain areas, it was always along a stereotyped, sequential, hierarchical pathway. The progression was categorized into 10 stages according to the brain regions affected: transentorhinal cortex (S1), entorhinal (S2), hippocampus (S3), anterior temporal cortex (S4), inferior temporal cortex (S5), medium temporal cortex (S6), polymodal association areas (prefrontal, parietal inferior, temporal superior) (S7), unimodal areas (S8), primary motor (S9a) or sensory (S9b, S9c) areas, and all neocortical areas (S10). Up to stage 6, the disease could be asymptomatic. In all cases studied here, stage 7 individuals with two polymodal association areas affected by tau pathologic states were cognitively impaired.

CONCLUSIONS

The relationship between NFD and Alzheimer-type dementia, and the criteria for a biochemical diagnosis of AD, are documented, and an association between AD and the extent of NFD in defined brain areas is shown.

A gene for Meckel syndrome maps to chromosome 11q13

Meckel syndrome (MKS) is a rare autosomal recessive lethal condition of unknown origin, characterized by (i) an occipital meningo-encephalocele with (ii) enlarged kidneys, with multicystic dysplasia and fibrotic changes in the portal area of the liver and with ductal proliferation, and (iii) postaxial polydactyly. A gene responsible for MKS in Finland has been mapped to chromosome 17q21-q24. Studying a subset of Middle Eastern and northern African MKS families, we have recently excluded the chromosome 17 region and have suggested a genetic heterogeneity. In the present study, we report on the mapping of a second MKS locus (MKS2) to chromosome 11q13, by homozygosity mapping in seven families that do not show linkage to chromosome 17q21-q24 (maximum LOD score 4.41 at recombination fraction .01). Most interestingly, the affected fetuses of southern Tunisian ancestry shared a particular haplotype at loci D11S911 and D11S906, suggesting that a founder effect is involved. Our observation gives support to the clinical and genetic heterogeneity of MKS.

Severe brain and limb defects with possible autosomal recessive inheritance: a series of six cases and review of the literature

Six fetuses with normal chromosomes were found to have severe craniofacial, limb, and visceral malformations during the second trimester of pregnancy. Two of these fetuses were monozygotic twins while a third one had a healthy dizygotic twin brother. A case with familial recurrence was also observed. Autopsy and skeletal radiographs suggested several diagnoses such as neural tube defect with limb defects or XK aprosencephaly. The development of these severe conditions in monozygotic twins and familial recurrence emphasize the difficulties of genetic counseling in such situations. These cases may suggest autosomal recessive inheritance.

Glial reaction in the hippocampal formation is highly correlated with aging in human brain

Glial fibrillary acidic protein (GFAP), a biochemical marker of astrocytes and glial reaction, was quantified by immunoblotting in different brain areas from 33 non-demented patients with a Mini Mental State Examination score above 26 and aged from 12 to 98 years. An increase of GFAP with age was first found in the hippocampus and then in the entorhinal cortex. In both regions, GFAP amounts were correlated with age (r = 0.768). In the isocortex, the increase of GFAP as a function of age was also significant (r = 0.672), but less than for the hippocampal region. GFAP levels increased dramatically after the age of 65 years, and more especially in the hippocampal formation. This glial reaction was observed in aged controls that do not show cognitive impairment and the neuropathological hallmarks of Alzheimer's disease.

[Diagnosis of fetal akinesia except for oligoamnios]

The term Fetal Akinesia Sequence (FAS) covers a large spectrum of developmental abnormalities resulting from a lack of intra-uterine fetal movements, which share heterogeneous etiologies. Environmental, "extrinsic" causes are easily ruled out. Various neuromuscular disorders, involving the motor unit at any level, constitute the main part of "intrinsic" fetal pathology. We propose a detailed schedule of prospective investigation of FAS, in order to standardize and gather the most pertinent information and to compare a wide panel of accurate data between fetopathological centers. The objective is to improve the understanding of various pathogenetic processes involved in the emergence of FAS, in order to propose better information and genetic counselling to parents, and potentially, to consider a prenatal prevention.

Fetal serum interferon-alpha suggests viral infection as the aetiology of unexplained lateral cerebral ventriculomegaly

We assayed fetal serum interferon-alpha (IFNA), a cytokine produced by leukocytes as a response to viral infection, in a series of 59 consecutive cases of ventriculomegaly diagnosed in utero and in 89 controls. Results were correlated with other findings including karyotype, maternal-fetal screening for serum antibodies to specific infectious pathogens, viral cultures of amniotic fluid, and neuropathological examination or postnatal follow-up. Fetal serum IFNA assay was negative in the five ventriculomegalies associated with a genetic anomaly and positive in the three cases with documented cytomegalovirus infections. In addition, fetal serum IFNA was detected significantly more often in the cases of ventriculomegaly with unexplained pathogenesis (15/51, 29.4 per cent) than in controls (1/89, 1.1 per cent). Detection of IFNA suggestive of viral infection in fetuses with otherwise unexplained ventriculomegaly underscores the need for more extensive viral screening in such cases.

[Multiple cortical photolesions and penicillin epileptogenic focus. Study of a model in rabbits]

Inactivation of an epileptogenic focus by dividing it into sub-unities unable to maintain epileptic activity has been demonstrated in animals. Based on these experiments, multiple subpial transections have been performed in patients suffering from partial drug-resistant epilepsies when resection of the epileptogenic cortex was not possible. In order to develop a new surgical technique for such epilepsies, the authors present an initial study of multiple cortical laser photolesions on the rabbit brain. The aim of this study is to assess the histological lesions created on the cortex with a laser at a chronic stage, and to compare the electrical paroxysmal activity of a penicillin focus on the laser irradiated cortex and on the non radiated cortex in the same animal. Twenty-five adult albino rabbits were used for this study. Both hemispheres of 19 rabbits have been exposed; 14 to 35 photolesions in a network were performed on one hemisphere using a 1.064 microns wavelength Nd-YAG laser. Six to twenty-one days later, a penicillin-induced focus was created on both hemispheres, a corticographic study was performed, and each animal was sacrificed for histological study of the brain. For the 6 last animals a high-power 0.805 micron wavelength diode laser was used with the same protocol. Histological study was solely performed in order to compare the effects of both lasers. In 11 animals electrocorticographic control was reliable. Time to first spike occurrence after penicillin application was significantly increased on the treated hemisphere as compared to the untreated one (1' to 14'30" and 10" to 6', respectively; p < 0.01) and the number of spikes per minute at early and late counts was significantly smaller on the treated hemisphere as compared to the untreated one (1 to 29 and 2 to 70, respectively; p < 0.02). Histologically the lesions appeared as cone-shaped coagulation necrosis surrounded by an area of macrophagic reaction, angiogenesis and gliosis. With the diode laser, some lesions included ischemic changes extended in the white matter. This study demonstrated the possibility of creating limited and reproducible photolesions using the laser light energy, without extensive destruction of the cortex. These lesions were reaching from one third to the totality of the cortical depth, depending on laser exposure parameters. This study also demonstrated that these photolesions arranged in a network and at a chronic stage were associated with a significantly reduced paroxysmal activity of a penicillin focus when compared to intact cortex. Since such lesions did not totally isolate cortical sub-unities, spiking was still recorded from the irradiated cortex, but at a lower rate, suggesting a disorganization of the local neuronal network responsible for paroxysmal activity.

Cortical mapping of Alzheimer pathology in brains of aged non-demented subjects

1. The presence of Alzheimer-type neurofibrillary pathology and amyloid deposits within the brains of 27 aged non-demented subjects was investigated by immunoblotting and immunohistochemistry using antibodies directed against pathological Tau proteins 55, 64 and 69 and beta A4 respectively. 2. The abnormal Tau triplet, a biochemical marker of neurofibrillary degeneration was quantified by western blot and densitometric analysis in several cortical areas including the entorhinal cortex (EC), hippocampus and Brodmann areas (BA) 38, 20, 22, 35, 9, 44 and 39. 3. The abnormal Tau triplet was detected in the EC and the hippocampus of most of the controls aged over 70 years. In few control cases abnormal Tau proteins were also detected in the isocortex, in BA38 alone or also in BA20. Some cases and especially those with Tau pathology in the temporal lobe contained numerous senile plaques (SP) in the neocortex. 4. The authors conclude that control cases with Tau pathology in the temporal lobe and numerous SP in the neocortex were likely to be subclinical stages of AD whereas others with Tau pathology exclusively detected in the EC and hippocampus and without or few SP in the neocortex were related to normal aging.

Quantitation of Alzheimer's amyloid peptide and identification of related amyloid proteins by dot-blot immunoassay

In Alzheimer's disease, the main component of amyloid deposits is a 39-43 amino acid peptide referred to as amyloid peptide or A beta. A crucial issue in the study of this disorder is to define the sequence of events that lead to amyloid deposition. In the present study, a new approach was developed that allows to specifically solubilize A beta peptide trapped within amyloid deposits and to quantify its amount by dot-blot immunoassay. The present method also permits to isolate components tightly bound to A beta and that are likely to catalyze its aggregation. Biochemical A beta quantitation was performed in 4 Brodmann areas from 17 elderly individuals exhibiting different degrees of amyloidosis. In parallel, classical neuropathology was done by histochemical and immunohistochemical methods. A beta amounts (pmol) were correlated to the number of amyloid deposits determined by neuropathology showing high statistical significance. Moreover, amyloid-binding proteins including apolipoprotein E and heparan sulfate proteoglycans were also found associated to A beta in the amyloid preparation. The present biochemical procedure is a new and reliable method to quantify amyloid deposition in brain. Furthermore, it allows to detect amyloid-associated components such as apolipoprotein E, that may be involved in the pathological process of amyloidogenesis.

Syndromal hypothalamic hamartoblastoma with holoprosencephaly sequence, microphthalmia, pulmonary malformations, radial hypoplasia and müllerian regression: further delineation of a new syndrome?

A 24-week-old fetus is described here with holoprosencephaly sequence (arhinencephaly and agenesis of the corpus callosum) associated with brain and meningeal dysplasia, microphthalmia with an ectopic pigmentary layer, hypothalamic hamartoblastoma, preaxial asymmetric limb reduction, lung hypoplasia, gastric hypoplasia, Müllerian regression, intestinal malrotation, asplenia, and normal chromosomes. The differential diagnosis includes the Cerebroacrovisceral-Early lethality (CAVE) phenotype, and the Pallister-Hall syndrome, but the anomalies best fit the severe form of microgastria-limb reduction syndrome. Together with a previous case reported by Meinecke, the pattern of anomalies appears to represent a combination of defects, related to but distinct from the microgastria-limb reduction syndrome.

[Normal cerebral aging: study of glial reaction]

Glial fibrillary acidic protein (GFAP), a biochemical marker of astrocytes and glial reaction, was quantified in different brain areas from 16 non-demented patients with a mini mental state score > 25/30 and aged from 21 to 95 years. For each brain, we analyzed the hippocampus (H), the parahippocampus gyrus (GPH) and the neocortical Brodmann areas 9, 22, 39, 44. The quantification of GFAP was performed on the different brain homogenates treated with SDS, using a Western blot method and an immunodetection with a monoclonal antibody against human GFAP. The quantity of GFAP found in the hippocampus and the parahippocampal region were significantly increased as a function of age (p < 0.001). This was not observed for neocortical areas. It has been shown that hippocampal and parahippocampal regions are specifically affected by the Alzheimer-type degenerating process during aging. Glial reaction, as visualized by immunoblotting, could be directly linked to this phenomenon.

Fetal enteroviral infection with cerebral ventriculomegaly and cardiomyopathy

Fetal cerebral ventriculomegaly and cardiomyopathy were diagnosed prenatally at 35 weeks and resulted in fetal death. Although there was no post mortem pathological evidence of inflammatory lesions, fetal serum alpha interferon was abnormally high (25 IU/ml). Virologic investigations were therefore carried out on stored amniotic fluid, fetal and maternal blood samples. The presence of enterovirus was retrospectively demonstrated in amniotic fluid. The association of fetal birth defects with enteroviral infection is puzzling and suggests that more attention should be given to virologic studies in the diagnostic workup of fetal malformations otherwise considered as idiopathic.

Autosomal dominant arteriopathic leuko-encephalopathy and Alzheimer's disease

A 49-year-old man suffered from progressive dementia and seizures leading to death after 2 years. CT scans showed severe cortical-subcortical atrophy and hypodensity of the white matter. His father had died at about the same age with similar clinical signs. Two sisters and one brother were also affected. Neuropathological study revealed predominant involvement of the cerebral white matter with myelin loss, gliosis and type I lacunes. The small arteries and arterioles of the white matter and basal ganglia, and, to a lesser extent those of the subarachnoidal space, displayed fibrosis and replacement of the media by an eosinophilic, PAS positive, Congo Red negative, granular substance. Electron microscopy showed swollen myocytes surrounded by collagen, elastin and a compact electron-dense material. Immunofluorescence using antibodies against IgA, IgG, IgM, C1q and C3 stained the abnormal media weakly. In the cortex, there were diffuse senile plaques and neurofibrillary tangles. Immunohistochemistry demonstrated beta/A4 positive material in cortical senile plaques but not in arterial walls. Adventitial macrophages were, however, immunoreactive for gamma-trace. Systemic arterioles were normal. The vascular changes and leukoencephalopathy are comparable to those described in 'Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy' (CADASIL). Similar vascular changes were also observed in nonfamilial cases. An association with Alzheimer changes in the cortex has not been described previously. The relationship between both diseases and the role of each in the causation of the dementia is unclear.

Presence of abnormally phosphorylated Tau proteins in the entorhinal cortex of aged non-demented subjects

An immunoblot study was performed in several cortical samples from non-demented aged controls and compared with those from Alzheimer patients, using antibodies against Tau 55, 64 and 69, which are specific and reliable markers of the neurofibrillary degeneration of the Alzheimer type. The immunodetection of Tau 55, 64 and 69 was positive in all cortical areas from Alzheimer patients, in the entorhinal cortex from each control aged more than 65 but not in cortical samples from younger controls. We demonstrate that the entorhinal cortex is the most vulnerable neuronal population in aging and that the biochemical dysfunctions observed in this area are typically of the 'Alzheimer-type'.

Intravascular lymphomatosis (neoplastic angioendotheliosis) of the central nervous system: case report and literature review

A 63-year-old woman developed gradual slowness, recurrent multifocal deficits, severe constitutional symptoms and hypopituitarism which progressed to death over 2.5 months. Elevation in lactico dehydrogenases was the main biological abnormality. Necropsy showed an intravascular malignant proliferation which proved to be a lymphoma of B-lineage. In order to better define diagnostic criteria, we reviewed previously reported cases of intravascular lymphomatosis of the central nervous system. A strategy for establishing the diagnosis is proposed.

Senile dementia of the Alzheimer type: is there a correlation between entorhinal cortex and dentate gyrus lesions?

Senile plaques (SP) are one of the neuropathological hallmarks of senile dementia of the Alzheimer type (SDAT). In 14 patients affected with SDAT (over 74 years of age), thioflavine S, Tau and acetylcholinesterase (AChE) stainings demonstrated an increased density of SP in the outer two thirds of the dentate gyrus molecular layer. However, a wide range of SP density was observed among the cases. The molecular layer of the dentate gyrus is one of the termination site of the perforant pathway that originates in layers II and III of the entorhinal cortex. We have found that the number of AChE-, thioflavine S- and Tau-positive SP that accumulate in the dentate gyrus is positively correlated with the density of thioflavine S-stained neurofibrillary tangles in layers II and III of the entorhinal cortex. In contrast, a similar correlation is not found when using Tau immunolabeling of the entorhinal tangles. These observations show an association between the accumulation of AChE-positive SP in the dentate molecular layer and the lesions of the perforant pathway. Furthermore, they suggest that the density of SP in the dentate gyrus correlates with the late stages of neurofibrillary tangles formation (thioflavine S positive), but not with the early stages (Tau positive).

[Neuropathologic validation of clinical diagnosis of senile dementia of the Alzheimer type]

The purpose of this work was to establish a neuropathological confirmation of the clinical diagnosis of senile dementia of the Alzheimer type (SDAT) in a group of patients prospectively studied in a geriatric hospital since 1984 (Charles Richet Study). The sample consisted of 45 cases, 35 of which had received a clinical diagnosis of SDAT and 10 others a diagnosis of either vascular or mixed dementia. The mean age at death was 85 +/- 6.9 years (range 64-97). The neuropathological diagnosis was established independently of the clinical findings. Senile lesions typical of SDAT were found in 32/35 cases, giving a 91.4% rate of clinico-pathologic agreement. However, vascular lesions were present in 10 cases (28.5%) and the final pathologic diagnosis was mixed dementia, lowering the score of agreement for SDAT to 63%. Considering that the pathological criteria for the diagnosis of SDAT are not uniform, we independently applied 3 inclusion (senile lesions) and 3 exclusion (vascular lesions) criteria for the diagnosis of SDAT to each of the 45 cases. This permitted a comparison of nine combinations of neuropathological criteria with the clinical diagnosis. The sensitivity values ranged from 37 to 80% and the specificity values ranged from 55 to 100%. The highest agreement rate with the clinical diagnosis was achieved when were associated the criterion which specified that plaques and tangles must be present in the hippocampus regardless of neocortical findings and the criterion which excluded cases with vascular lesions of any site if their volume was 50 ml or more.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of 1.32-micron Nd-YAG laser on brain thermal and histological experimental data

Considering that the 1.32-microns Nd-YAG laser should have physicothermal properties close to those of the CO2 laser, a series of experiments were conducted on rat cortex (N = 51). Three laser wavelengths were compared: CO2 laser (10.6 microns), 1.06-microns Nd-YAG, and 1.32-microns Nd-YAG lasers. For each shot, temperature measurements were recorded with an infrared thermographic videocamera. The digitized signals were figured as thermal profiles and temperature developments. Ninety-five shots were correctly studied and analyzed: CO2, N = 29; 1.06-microns Nd-YAG, N = 20; 1.32-microns Nd-YAG, N = 46. The histological lesions produced by these three lasers were compared on animals killed 24 hours (N = 20), 8 days (N = 20), and 30 days (N = 5) after the laser impacts. For equivalent densities of energy, the depth of cortical necrosis was comparable for the CO2 laser (200-250 microns) and the 1.32-microns Nd-YAG laser (210-260 microns) whatever the date of death; the 1.06-microns Nd-YAG laser shots were responsible for much more important damage (400-550 microns). Because of its important absorption in water and nervous tissue, the authors consider the 1.32-microns Nd-YAG laser most suitable for neurosurgery, particularly because it is conducted through optic fibers, and therefore is easy to handle during neurosurgical procedures.