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Biomedical subjects

D Seilhean

Publications and source records attributed to D Seilhean.

At least 19 recordsLinked to original sources

Reversible encephalopathy associated with cholesterol embolism syndrome: magnetic resonance imaging and pathological findings.

We describe a patient found to have acute diffuse and reversible encephalopathy on magnetic resonance imaging (MRI) associated with cholesterol emboli syndrome (CES). The initial MRI showed extensive white matter, basal ganglia and cortical damage without evidence of brain infarction. Dramatic clinical and MRI improvement was observed with corticosteroids. Pathologically, cholesterol crystal emboli were found in the lumen of skin and brain arteries and were associated with varying degrees of inflammation of the arteriole wall. This case suggests that CES may be responsible for extensive, acute and reversible encephalopathy underlined by an inflammation of brain arteries.

Acute Disease↗

How a neuropsychiatric brain bank should be run: a consensus paper of Brainnet Europe II.

The development of new molecular and neurobiological methods, computer-assisted quantification techniques and neurobiological investigation methods which can be applied to the human brain, all have evoked an increased demand for post-mortem tissue in research. Psychiatric disorders are considered to be of neurobiological origin. Thus far, however, the etiology and pathophysiology of schizophrenia, depression and dementias are not well understood at the cellular and molecular level. The following will outline the consensus of the working group for neuropsychiatric brain banking organized in the Brainnet Europe II, on ethical guidelines for brain banking, clinical diagnostic criteria, the minimal clinical data set of retrospectively analyzed cases as well as neuropathological standard investigations to perform stageing for neurodegenerative disorders in brain tissue. We will list regions of interest for assessments in psychiatric disorder, propose a dissection scheme and describe preservation and storage conditions of tissue. These guidelines may be of value for future implementations of additional neuropsychiatric brain banks world-wide.

Brain↗

Nodal, paranodal and juxtaparanodal axonal proteins during demyelination and remyelination in multiple sclerosis.

Saltatory conduction in myelinated fibres depends on the specific molecular organization of highly specialized axonal domains at the node of Ranvier, the paranodal and the juxtaparanodal regions. Voltage-gated sodium channels (Na(v)) have been shown to be deployed along the naked demyelinated axon in experimental models of CNS demyelination and in multiple sclerosis lesions. Little is known about aggregation of nodal, paranodal and juxtaparanodal constituents during the repair process. We analysed by immunohistochemistry on free-floating sections from multiple sclerosis brains the expression and distribution of nodal (Na(v) channels), paranodal (paranodin/Caspr) and juxtaparanodal (K(v) channels and Caspr2) molecules in demyelinated and remyelinated lesions. Whereas in demyelinated lesions, paranodal and juxtaparanodal proteins are diffusely distributed on denuded axons, the distribution of Na(v) channels is heterogeneous, with a diffuse immunoreactivity but also few broad Na(v) channel aggregates in all demyelinated lesions. In contrast to the demyelinated plaques, all remyelinated lesions are characterized by the detection of aggregates of Na(v) channels, paranodin/Caspr, K(v) channels and Caspr2. Our data suggest that these aggregates precede remyelination, and that Na(v) channel aggregation is the initial event, followed by aggregation of paranodal and then juxtaparanodal axonal proteins. Remyelination takes place in multiple sclerosis tissue but myelin repair is often incomplete, and the reasons for this remyelination deficit are many. We suggest that a defect of Na(v) channel aggregation might be involved in the remyelination failure in demyelinated lesions with spared axons and oligodendroglial cells.

Adult↗

Devic's neuromyelitis optica: study of nine cases.

OBJECTIVE: Multiple sclerosis (MS) is by far the most popular diagnosis for patients with multifocal neurological disease. Owing to demyelinating inflammatory non-necrotic plaques of the white matter, MS can give remitting symptoms of virtually every part of the central nervous system. Corticosteroids are usually helpful. Devic's neuromyelitis optica (DNMO) is a neurological disease involving only the optic nerves and the spinal cord, where demyelination evolves towards necrosis and atrophy; the prognosis is poor and no satisfactory treatment is known. The objectives of this study are to describe clinical, biological, pathological and radiological data of patients with DNMO and to differentiate DNMO from MS. MATERIAL AND METHODS: We studied the files of 14 patients diagnosed with possible DNMO in three French hospitals between 1980 and 1999 and reviewed the literature. RESULTS: Nine patients were included as definite DNMO. Five were excluded because they did not fulfil the diagnostic criteria. For the nine patients with definite DNMO, DNMO was either monophasic or multiphasic. The prognosis was generally poor: two patients died and five others developed severe disability such as blindness, para or quadriplegia or both. Cerebrospinal fluid study and neuroimaging were essential to confirm the diagnosis of DNMO. Various immunosuppressive treatments generally failed to benefit the patients. CONCLUSION: In the literature (as well as our 14 initial patients) only a few cases of patients described as suffering from DNMO fulfilled the diagnostic criteria. The others showed evidence that another disease like MS was involved. We stress that inclusion and exclusion criteria have to be kept in mind to differentiate clearly DNMO from MS and other central nervous system white matter diseases.

Adolescent↗

Long-term survival after gene therapy for a recurrent glioblastoma.

A patient presenting with a recurrent glioblastoma (GBM) survived 3 years after suicide gene therapy and finally died of a disseminated breast cancer with no indication of tumor recurrence on MRI. Postmortem analysis showed no evidence of recurrence of the GBM, neither near the initial tumor localization nor in any other area of the brain. Such an evolution is unusual in the course of this disease and may suggest in this particular case a cure of the GBM.

Adult↗

The relationship between Bunina bodies, skein-like inclusions and neuronal loss in amyotrophic lateral sclerosis.

Specific pathological hallmarks have been described in amyotrophic lateral sclerosis (ALS), which include motor neuronal loss, Bunina bodies (BBs) and skein like inclusions (SLIs). We investigated the relation between these three lesions in the cervical and lumbar anterior horns and the hypoglossal nuclei of 20 ALS patients and 9 controls using a quantitative light microscopy study. Immunohistochemistry with anti-cystatin C and anti-ubiquitin was used to detect the BBs and SLIs, respectively. A significant relation between the severity of neuronal loss and the proportion of SLI-containing neurons was found in the spinal cord, whereas no relation was found with BBs. We therefore propose that BBs and SLIs participate in two different steps of the cascade leading to neuronal loss.

Adult↗

[Neuropathology of the cerebral vessels of centenarians].

Neuropathological study of brain and brain vessels was performed in two series of 12 and 20 centenarians, focusing on the prevalence of small vessel lesions, infarction, Alzheimer's changes and mental status. These are discussed as a function of vascular risk factors. In the first series (12 cases), there was no correlation between the severity of small vessel lesions: hyalinosis (12/12), mineralisation (10/12), amyloid angiopathy (9/12), vascular risk factors (high blood pressure or diabetes), Alzheimer's lesions. However, there was a tendency for an association between amyloid angiopathy and high density of neurofibrillary tangles. In the second series (20 cases), small infarcts and lacunes were found in 9/20 cases, neurofibrillary tangles and diffuse deposits of A beta peptide were constant, senile plaques were very frequent (19/20). Five patients were demented (one vascular dementia, one Alzheimer dementia, and 3 mixed dementias). These data indicate that: 1) Lesions of the walls of small cerebral vessels do not seem linked to the vascular risk factors observed at the end of the life of centenarians. 2) Cerebral infarcts and lacunes are frequent in these patients, and are responsible, at least in part, for a high proportion of the cognitive dysfunctions. The study of larger series is needed for a better understanding of relationships between vascular and degenerative lesions in the oldest old.

Aged↗

[Autopsy and religions].

Concerns about autopsies may hardly leave behind religious belief. Traditional anthropology conditions the relationship to death. No main religion practiced in the regions where autopsies are performed forbids it definitely. Judaism and Islam accept it as far as its usefulness is demonstrated. Christianity encourages the generosity of donation. Buddhism, which developed a denial of appearances, is finding ways to dialogue with the need of medical practices in the western world. The repulsion induced by the exploration of a corpse takes origin far above dogma and belief, which formulate acceptable limits within a given culture. Because autopsy remains useful, laic society must take into account not only the beliefs of humans, but also their fundamental need of sublimation in front of death.

Autopsy↗

Hallucinations, REM sleep, and Parkinson's disease: a medical hypothesis.

BACKGROUND: Patients with PD can have disabling visual hallucinations associated with dopaminergic therapy. Sleep disorders, including vivid dreams and REM sleep with motor behaviors (RBD), are frequent in these patients. METHODS: The association of hallucinations and REM sleep both at night and during the day was examined in 10 consecutive nondemented patients with long-standing levodopa-responsive PD and hallucinations. Seven patients presented with paranoia and paranoid delusions. Overnight sleep recordings and standard multiple daytime sleep latency test were performed. The results were compared to those of 10 similar patients with PD not experiencing hallucinations. RESULTS: RBD was detected in all 10 patients with hallucinations and in six without. Although nighttime sleep conditions were similar in both groups, hallucinators tended to be sleepier during the day. Delusions following nighttime REM period and daytime REM onsets were observed in three and eight of the hallucinators, and zero and two of the others. Daytime hallucinations, coincident with REM sleep intrusions during periods of wakefulness, were reported only by hallucinators. Postmortem examination of the brain of one patient showed numerous Lewy bodies in neurons of the subcoeruleus nucleus, a region that is involved in REM sleep control. CONCLUSION: The visual hallucinations that coincide with daytime episodes of REM sleep in patients who also experience post-REM delusions at night may be dream imagery. Psychosis in patients with PD may therefore reflect a narcolepsy-like REM sleep disorder.

Aged↗

PrP immunohistochemistry: different protocols, including a procedure for long formalin fixation, and a proposed schematic classification for deposits in sporadic Creutzfeldt-Jakob disease.

The use of immunohistochemistry on formalin-fixed and paraffin-embedded tissue has greatly improved the neuropathological diagnosis of Creutzfeldt-Jakob disease and the other subacute spongiform encephalopathies in human and animals. Two pitfalls of this technique, however, currently exist: low sensitivity after long formalin fixation and difficulties in interpreting some images. Here we review the protocols currently in use for the pretreatment of sections allowing PrP detection by immunohistochemistry. In addition, a technique useful after long formalin fixation is reported: enzymatic digestion with proteinase K (24 degrees C, 1/100 for 8 minutes) was employed in addition to the usual autoclaving (121 degrees C for 10 minutes) followed by formic acid (99% for 5 minutes) and 4M guanidine thiocyanate (4 degrees C for 2 hours). This allowed a substantial increase in the sensitivity of 3F4 immunohistochemistry on paraffin-embedded tissue, especially after prolonged formalin fixation. In addition, we suggest a simple method for classification of PrP immunolabelling in sporadic Creutzfeldt-Jakob disease that would allow easy comparisons.

Brain↗

Similar subcortical pattern of cognitive impairment in AIDS patients with and without dementia.

The aim of this study was to develop a series of neuropsychological tests that define the cortical and subcortical features of cognitive impairment and the characteristics of memory in demented and mildly cognitively impaired AIDS patients. We attempted to establish a usable method to assess and determine the type and degree of cognitive impairment in individual AIDS patients. We examined 53 patients without central nervous system opportunistic infections. A short battery included two scales of global efficiency (the Mattis dementia rating scale and the Mini Mental State Examination), a psychomotor speed test, an executive control assessment and explicit memory evaluation. Patients were categorized into four groups based on their score on both the Mattis dementia rating scale and the DSM-IV criteria: (1) asymptomatic; (2) having AIDS without cognitive impairment; (3) having AIDS with mild cognitive impairment; and (4) having AIDS dementia. Patients with mildly impaired cognition demonstrated slowed thinking, abnormal initiation and conceptualization, and memory impairment. AIDS dementia patients had slower motor activity and memory recall was more severely affected. The short neuropsychological battery was able to characterize modified cognitive performances in both severely and mildly cognitively impaired AIDS patients. The subcortical pattern of the memory disorder was obvious, regardless of the degree of cognitive impairment.

AIDS Dementia Complex↗

[Research on multiple sclerosis and tissue banks].

Tissue banks are of major importance in research on human tissues, in particular as regards the furthering of our knowledge on multiple sclerosis (MS). Individuals who wish to make a 'donation of their brain' for autopsy, or pathologists in possession of biopsy specimens that have not been utilized for diagnosis provide the necessary material for investigation by research teams. In addition to their technical aspects, brain tissue banks provide information and aid in promoting research. Their functioning, usually supported by patient associations, has encountered certain difficulties. At present, it is challenged by a decrease in the number of autopsies.

Autopsy↗

[Biopathology of transmissible subacute spongiform encephalopathies].

Three lesions can be seen in the central nervous system: vacuolation ("spongiform state"), hypertrophy and proliferation of astrocytes ("astrogliosis"), and neuronal loss. These are poorly specific changes. In contrast, amyloid plaques and other deposits of PrPres are very specific lesions. The recent widening of the clinico-pathological spectrum of PrPres-induced disorders has shown that none of these lesions was constantly present. The mechanisms of PrPres occurrence and development, neuronal death, involvement of the central nervous system after peripheral inoculation are still hypothetical. B lymphocytes, monocyte-macrophages, peripheral nerves, central synapses are important. New data will be provided by experimental models (transgenic mice, transplantations), and by a full study of all patients affected by prion diseases, which necessarily involves autopsy.

Animals↗

[Fronto-temporal degenerative dementia. A modern neuropathologic approach].

The classification of degenerative dementias with fronto-temporal atrophy has been debated since the description of Pick's disease. The study of a clinico-pathological series of 10 cases using immunohistochemistry lead to the following conclusions: reserving the name of Pick's disease to those cases with argyrophilic inclusions, the most recognisable and characteristic marker at neuropathological examination, allows an easy and reliable diagnosis; keeping on with the splitting of these disorders into various clinico-pathologic entities seems today more useful than grouping them into a single syndrome until new data, based for example on genetic analysis, show that different phenotypes correspond to the same disease.

Adult↗

Laminar spongiosis of the dentate gyrus: a sign of disconnection, present in cases of severe Alzheimer's disease.

An extensive laminar spongiosis was found in the outer part of the dentate gyrus in an 84-year-old patient. An old cavitary infarct in the parahippocampal gyrus disconnected the dentate gyrus from the entorhinal area. This finding prompted us to seek laminar spongiosis in Alzheimer's disease, where the neuronal loss in the entorhinal cortex might be severe. The dentate gyrus was systematically examined in a series of prospectively assessed cases either intellectually normal or affected by mental impairment of graded severity. Laminar spongiosis was present in the most severely affected patients. The neuritic crown of the senile plaques seen in the laminar band of spongiosis contained only a few tau- and Bodian-positive fibers, a sign that was taken as evidence of "plaque denervation". By contrast, deposits of Abeta peptide remained abundant but lacked a dense core. These data suggest that dendritic and axonal processes are intermingled in the senile plaque and that the amyloid core is at least partially dependent on the presence of the axonal component.

Aged↗