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M M Ruchoux

Publications and source records attributed to M M Ruchoux.

At least 37 records · Page 2Linked to original sources
PubMed2000

Cerebellar gliomas in children with NF1: pathology and surgery.

Cerebellar gliomas associated with NF1 (CGNF1) are rarely reported in the literature, and they are considered to be malignant in a high proportion of cases. In an attempt to improve the definition of this disease and clarify its management, we reviewed our patients with CGNF1 and compared their tumors with sporadic cerebellar gliomas (SGC). We operated on six children with CGNF1, all but one of whom were asymptomatic. They represented one-tenth of all pediatric cerebellar gliomas, and one third of NF1-associated gliomas seen in our institution. CGNF1 appeared at a later age than SCG. They are seated near the roof of the IV ventricle and are not related to white matter hypersignal hamartomas. Most of these tumors showed radiological progression. They were four pilocytic astrocytomas, one ganglioglioma, and one malignant astrocytoma. One patient had tumor recurrence after 8 years, and the others are still disease free. The overall outcome appeared to be better for GCNF1 than for SCG. On account of the regular growth, uncertain pathology, and good surgical outcome, we advocate systematic resection of these tumors.

Adolescent↗
PubMed2000

Skin biopsy value and leukoaraiosis.

In the field of leukoaraiosis, the identification of CADASIL and its link to Notch 3 mutation has shed light on the pathogenesis of white matter (WM) abnormalities related to small-vessel disease. Since 1993, its systemic vascular involvement allows skin biopsy diagnosis and research on tissues before postmortem examination. We received 160 skin biopsies from patients presenting subcortical dementia, recurrent strokes, behavioral disturbances or migraines, and suspected CADASIL. Almost all the patients lacked the well-known vascular risk factors. The ultrastructural study was systematically carried out looking at the vessel walls and the other components found in skin. In a third, we found endothelial changes, destruction of vascular smooth muscle cells (VSMCs), and characteristic granular osmiophilic material (GOM). In these cases, the genetic analysis confirmed the Notch 3 mutation. Curiously, the skin biopsies from the other two thirds presented marked alterations within the vessel walls. Such changes included destruction of VSMCs, lack of GOM, and replacement of these cells by an extracellular matrix. Frequently, we noticed endothelial pathological changes as well as other tissue impairments. By now, we are able to describe eight different groups of lesions according to either the prevalence of a lesion or the association of different lesions. The skin biopsy ultrastructural study seems to be highly informative given that we can observe vessel lesions and association of impairments in various tissues that might, in part, explain the brain vessel involvement and then the leukoaraiosis and probably some clinical symptoms. Moreover, these vessel lesions often belonged to young people (30-50 years old), and many of them seemed to run in families. These new data associated with early onset of clinical symptoms and leukoaraiosis would be extremely valuable in clarifying the wide field of leucoencephalopathy and might provide genetic research with new issues.

Adult↗
PubMed2000

Pineal parenchymal tumors: a correlation of histological features with prognosis in 66 cases.

The WHO classification of CNS tumors divides pineal parenchymal tumors (PPT) into pineocytoma (PC), pineoblastoma (PB) and mixed pineocytoma-pineoblastoma or PPT with intermediate differentiation. The reported incidence of mixed/intermediate PPT varies and this may reflect the difficulty in classifying tumors of this type. In an attempt to overcome the problem of the classification of PPT with intermediate differentiation, we describe the relationship between histological features and patient survival in a large cooperative series of 66 PPT from 12 neurosurgical centres. All tumors were studied with both light microscopy and immunohistochemically using antibodies against glial markers or neural/neuroendocrine markers. Our series included 11 PC, 39 mixed/intermediate PPT and 16 PB. A number of mitoses greater than 6 and the presence of necrosis were associated with a poorer outcome, while positive immunostaining for neurofilaments was associated with a better survival. We propose a new prognostic grading of 4 grades, grade I for PC, grade II for PPT with fewer than 6 mitoses and positive immunolabelling for neurofilaments, grade III for PPT with either 6 or more than 6 mitoses or fewer than 6 mitoses but without immunostaining for neurofilaments and grade IV for PB.

Adolescent↗
PubMed1999

Simultaneous presentation of atypical teratoid/rhabdoid tumor in siblings.

Atypical rhabdoid/teratoid tumor (ATT/RHT) is a rare malignant neoplasm which appears in early childhood. The present paper describes clinical and pathological features of ATT/RHT which occurred simultaneously in 2 sisters diagnosed at a 15 day interval. Both children were treated by surgical resection, subtotal in the first case and total in the second. Postoperatively, chemotherapy followed by radiotherapy, 50.4 Gy on the posterior fossa, were administered. Despite this therapy, both sisters died at 14 months and 26 months respectively. The tumors express vimentin and EMA; cells contained intracytoplasmic inclusions. No karyotypic anomaly was detected. This is the first description of familial ATT/RHT.

Brain Neoplasms↗
PubMed1999

Supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas are characterized by a differential expression of S100 proteins.

The levels of expression of the S100A1, S100A2, S100A3, S100A4, S100A5, S100A6 and S100B proteins were immunohistochemically assayed and quantitatively determined in a series of 95 astrocytic tumors including 26 World Health Organization (WHO) grade I (pilocytic astrocytomas), 23 WHO grade II (astrocytomas), 25 WHO grade III (anaplastic astrocytomas) and 21 WHO grade IV (glioblastomas) cases. The level of the immunohistochemical expression of the S100 proteins was quantitatively determined in the solid tumor tissue (tumor mass). In addition twenty blood vessel walls and their corresponding perivascular tumor astrocytes were also immunohistochemically assayed for 10 cases chosen at random from each of the four histopathological groups. The data showed modifications in the level of S100A3 protein expression; these modifications clearly identified the pilocytic astrocytomas from WHO grade II-IV astrocytic tumors as a distinct biological group. Modifications in the level of S100A6 protein expression enabled a clear distinction to be made between low (WHO grade I and II) and high (WHO grade III and IV) grade astrocytic tumors. Very significant modifications occurred in the level of S100A1 protein expression (and, to a lesser extent, in their of the S100A4 and S100B proteins) in relation to the increasing levels of malignancy. While the S100A5 protein was significantly expressed in all the astrocytic tumors (but without any significant modifications in the levels of malignancy), the S100A2 protein was never expressed in these tumors. These data thus indicate that several S100 proteins play major biological roles in human astrocytic tumors.

Adolescent↗
PubMed1999

[Angiogenesis and neuropathology].

Angiogenesis is crucial for both tissue development and tissue function and is an integral part of central nervous system embryogenesis and tumor growth. Angiogenesis is extremely active during development, then remains stable during adulthood and decreases gradually during aging. Physiological processes and inflammation can transiently stimulate angiogenesis in adults. Angiogenesis is modulated by a host signaling pathways, growth factors, growth factor receptors, and membrane proteins associated with these receptors or transcription factors. In disorders affecting the central nervous systems, as in those arising elsewhere in the body, angiogenesis can become inadequate, excessive, or qualitatively abnormal (dysplasia). These abnormalities can result in cerebral trophic disorders and in secondary remodeling. A few examples are given to illustrate various types of primary angiogenesis disorders responsible for cerebral lesions and of secondary angiogenesis disorders caused by an underlying cerebral disorder.

Adult↗
PubMed1998

In vivo diagnosis of Kufs' disease by extracerebral biopsies.

In almost all of the earlier reported cases of Kufs' disease, the adult form of ceroid lipofuscinosis, the diagnosis was ascertained by cerebral tissue examination, while peripheral biopsy examination revealed an apparent poor diffusion of specific lipofuscinic deposits, the finger print profiles (FPs). We report the ultrastructural data from skin, muscle and rectal biopsy specimens from two siblings, both still living, who present clinical features of Kufs' disease. We observed the presence of FPs in locations that differ from the previous classic reports. Our results emphasize the value of extracerebral biopsies for the diagnosis of Kufs' disease in vivo, and suggest some physiopathological assumptions based on vascular wall involvement.

Adult↗
PubMed1998

Differential diagnosis of a vascular leukoencephalopathy within a CADASIL family: use of skin biopsy electron microscopy study and direct genotypic screening.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a condition caused by mutations of Notch3 gene on chromosome 19. Ultrastructural analysis of skin vessels discloses typical granular osmiophilic material (GOM) within the vascular smooth muscle basal lamina. We describe a CADASIL family in which two members suffering from a vascular leukoencephalopathy were shown to be CADASIL phenocopies: clinical and magnetic resonance imaging (MRI) findings in these two patients were similar to those observed in their affected relatives. However, the skin biopsy performed on one of them did not reveal any GOM in the vascular smooth muscle cells, and the Notch3 mutation present in this family was shown to be absent in these two individuals. We emphasize the role of a direct DNA test for gene mutation to make a differential diagnosis between CADASIL and other forms of vascular leukoencephalopathy.

Adult↗
PubMed1998

Endothelial changes in muscle and skin biopsies in patients with CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is characterized by the deposition of granular osmiophilic material in association with vascular smooth muscle cells in many different organs. However, the cause of the subsequent destruction of smooth muscle cells that are surrounded by granular osmiophilic material is unclear. In the present study, the ultrastructural changes that occur in endothelial cells in CADASIL have been evaluated by examining blood vessels in six skin biopsies and seven muscle biopsies belonging to three different CADASIL pedigrees. The appearances have been compared with five skin biopsies and five muscle biopsies from age-matched controls without vascular disease. The most striking features observed in vessels in the skin of CADASIL patients were attenuation of endothelial cells and increased density of endothelial cytoplasm, accompanied by the presence of compact bundles of microfilaments within the cytoplasm of endothelial cells. Endothelial cells in muscle biopsies from CADASIL patients, on the other hand, were swollen until destruction of tight junctions were observed. These findings suggest that impaired permeability of vascular endothelium may play a role in the destruction of vascular smooth muscle cells in CADASIL. Furthermore, the results of this study suggest that further fine structural investigation of blood vessel endothelium and underlying smooth muscle may lead to a better understanding of the pathophysiology of CADASIL.

Adult↗
PubMed1998

Lipomatous differentiation in ependymomas: a report of three cases and comparison with similar changes reported in other central nervous system neoplasms of neuroectodermal origin.

Three cases of surgically removed ependymomas with lipomatous transformation of tumor cells are reported. Patients' ages were 13, 16, and 48 years at the time of operation. One patient's tumor was located in the third ventricle; the other two occupied paraventricular hemispheric white matter. Histologically all three cases fulfilled the criteria of ependymomas. In case 1, electron microscopy also confirmed this diagnosis, and preoperative radiologic studies (scans) suggested large amounts of lipids to be present in the tumor. Histologically, in all three cases many tumor cells contained fat droplets coalescing into a single large droplet, resulting in an appearance indistinguishable from adipocytes by conventional stains, but maintaining immunohistological positivity for glial fibrillary acidic protein and neuron-specific enolase in the cytoplasmic rims of the affected cells, attesting to their glial nature as opposed to being true adipocytes in a mixed glial/mesenchymal hamartoma. The alterations were also different from the "xanthomatous" changes seen in some gliomas. Lipomatous transformation of neuroectodermal tumor cells has been previously observed in neurocytomas, medulloblastomas, cerebellar and spinal cord astrocytomas, and primitive neuroectodermal tumors. Our three cases represent the first reported ependymomas with such changes. In medulloblastomas of adults, lipomatous changes have been found to signal relatively benign biologic behavior. So far, all three of our patients are doing well, but only more extended follow-up will show whether such benign behavior applies to lipomatous ependymomas as well.

Adolescent↗
PubMed1998

Creutzfeldt-Jakob disease: neurophysiologic visual impairments.

OBJECTIVE: The predictive value of electrophysiologic visual testing in Creutzfeldt-Jakob disease (CJD) was investigated, and the retinal pathologic findings in three cases are reported. BACKGROUND: The fatal prognosis of CJD, its transmissibility, and the lack of treatment make early diagnosis essential in averting human-to-human transmission. Electroretinogram and visual evoked potentials have been studied in few cases of CJD. METHODS: A visual electrophysiologic examination was performed in 41 consecutive patients referred with suspected CJD. The disease had been diagnosed in 24 patients (CJD group; 15 were confirmed neuropathologically and 9 by clinicolaboratory methods in accordance with diagnostic criteria). The remaining 17 patients were diagnosed with other neurologic disorders, and served as a control group. RESULTS: Flash electroretinogram revealed a significant decrease in the amplitude of the B1 wave (<60 microV) and the B/A ratio (<2) in the CJD group compared with those in the control group. Flash visual evoked potentials revealed no significant difference in latency, but amplitude was increased (>10 microV) in the CJD group, especially in patients with myoclonus. CONCLUSIONS: The visual electrophysiologic abnormalities provide an interesting noninvasive diagnostic tool in idiopathic CJD. The B1-wave decrease is closely correlated with the outer plexiform layer abnormalities observed on neuropathologic examination.

Adult↗
PubMed1997

Notch3 mutations in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a mendelian condition causing stroke and vascular dementia.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited condition whose key features include recurrent subcortical ischemic events, migraine attacks and vascular dementia in association with diffuse white-matter abnormalities seen on neuroimaging. Pathologic examination shows multiple small deep cerebral infarcts, a leukoencephalopathy and a nonatherosclerotic nonamyloid angiopathy involving mainly the media of small cerebral arteries. To progress in understanding the pathophysiological mechanisms of this condition, we undertook the identification of the mutated gene. We mapped the CADASIL gene on chromosome 19p13.1. More than 120 families have been referred to our lab. Genetic linkage analysis of 33 of these families allowed us to reduce the size of the genetic interval to less than 1 cM and to demonstrate the genetic homogeneity of this condition. In the absence of any candidate gene, we undertook positional cloning of this gene. We identified, within the CADASIL critical region, the human Notch3 gene, whose sequence analysis revealed deleterious mutations in CADASIL families co-segregating with the affected phenotype. These data establish that this gene causes CADASIL. Identification of the CADASIL gene will provide a valuable diagnostic tool for clinicians and could be used to estimate the prevalence of this underdiagnosed condition. It should help in the understanding of pathophysiological mechanisms of CADASIL and vascular dementia.

Adult↗
PubMed1997

CADASIL: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a recently identified cause of stroke and vascular dementia. It is a condition of mid-adulthood due to mutations of Notch 3 gene on chromosome 19. Whereas the disease was first reported in European families, since 1993 CADASIL has been observed in American, African and Asiatic pedigrees, suggesting that today, the disease probably still remains largely underdiagnosed. The pathological data first dealt with the white matter and the basal ganglia showing the features observed in Binswanger's subcortical arteriopathic encephalopathy; over the past few years, CADASIL has become appreciated as a systemic vascular disease with specific features. Here we have reviewed the literature from 1977 to the present for pathologically and genetically verified cases accompanied by relatively complete clinical descriptions so as to give the pathological features associated with this condition a clearer definition. The review will focus mainly on pathological studies and the pathophysiological mechanisms most likely to be involved in CADASIL.

Cerebral Infarction↗
PubMed1997

[Mitochondrial anomalies in oculopharyngeal muscular dystrophy].

Oculopharyngeal muscular dystrophy (OPMD) was described by Taylor in 1915. This autosomal dominant inheritance affection begins at the age of 40-50 years associating bilateral ptosis and dysphagia. In 1980, Tome and Fardeau described rimmed vacuoles and typical intranuclear tubulo-filamentous inclusions in the muscle biopsy. We report two cases (brother and sister) of clinical and histological OPMD with mitochondrial abnormalities (Ragged red fibers) associated with classical OPMD lesions. Those observation remind the question already vised since a long time by some authors, of the signification of mitochondrial abnormalities in OPMD.

Female↗