62 resultados para temporal lobe epilepsy


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Neuronal intermediate filament (IF) inclusion disease (NIFID) is characterized by neuronal loss, neuronal cytoplasmic IF-positive inclusions (NI), swollen neurons (SN), and a glial cell reaction. We studied the spatial correlations between the clusters of NI, SN, and glial cells in four gyri of the temporal lobe (superior temporal gyrus, inferior temporal gyrus, lateral occipitotemporal gyrus, and parahippocampal gyrus) in four cases of NIFID. The densities of histological features (per 50x250 μ sample field) were as follows: NI (mean = 0.41, range 0.28-0.68), SN (mean = 1.41, range 0.47-2.65), glial cell nuclei (mean = 5.21, range 3.63-8.17). The NI and the SN were positively correlated in half of the brain regions examined, the correlations being present at the smallest field size (50x250 μm). The NI were also positively or negatively correlated with the glial cell nuclei in different areas, the negative correlations being present at the smallest field size. Glial cell nuclei were positively or negatively correlated with the SN in different brain areas, mainly at the larger field sizes (400x250 and 800x250 μm). The spatial correlation between the clusters of NI and SN in the cortex suggests their development within the same columns of cells. At first, the glial cell reaction is also confined to these columns but later becomes more generally distributed across the cortex. © Springer-Verlag 2004.

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Dementia with neurofilament inclusions (DNI) is a new disorder characterized clinically by early-onset dementia and histologically by the presence of intraneural inclusions immunopositive for neurofilament antigens but lacking tau and α-synuclein reactivity. We studied the clustering patterns of the neurofilament inclusions (NI) in regions of the temporal lobe in three cases of DNI to determine whether they have the same spatial patterns as inclusions in the tauopathies and α-synucleinopathies. The NI exhibited a clustered distribution (mean size of clusters 400 μm, range 50-800 μm, SD 687.8) in 24/28 of the areas studied. In 22 of these areas, the clusters exhibited a regular distribution along the tissue parallel to the pia mater or alveus. In 3 cortical areas, there was evidence of a more complex pattern in which the NI clusters were aggregated into larger superclusters. In 6 cortical areas, the size of the clusters approximated to those of the cells of origin of the cortico-cortical pathways but in the remaining areas cluster size was smaller than 400 μm. Despite the unique molecular profile of the NI, their spatial patterns are similar to those shown by filamentous neuronal inclusions in the tauopathies and α-synucleinopathies.

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Vacuolation ('spongiform change') and prion protein (PrP) deposition were quantified in the cerebral cortex, hippocampus, dentate gyrus and molecular layer of the cerebellum in 11 cases of variant Creutzfeldt-Jakob disease (vCJD). The density of vacuoles was greater in the cerebral cortex compared to the hippocampus, dentate gyrus and cerebellum. Within the cortex, vacuole density was significantly greater in the occipital compared to the temporal lobe and the density of surviving neurones was greatest in the occipital lobe. The density of the non-florid PrP plaques was greater in the cerebellum compared to the other brain areas. There were significantly more florid-type PrP plaques in the cerebral cortex compared to the hippocampus and the molecular layer of the cerebellum. No significant correlations were observed between the densities of the vacuoles and the PrP plaques. The densities of vacuoles in the parietal cortex and the non-florid plaques in the frontal cortex were positively correlated with the density of surviving neurones. The densities of the florid and the non-florid plaques were positively correlated in the parietal cortex, occipital cortex, inferior temporal gyrus and dentate gyrus. The data suggest: (i) vacuolation throughout the cerebral cortex, especially in the occipital lobe, but less evident in the hippocampus and molecular layer of the cerebellum; (ii) the non-florid plaques are more common than the florid plaques and predominate in the molecular layer of the cerebellum; and (iii) either the florid plaques develop from the non-florid plaques or both types are morphological variants resulting from the same degenerative process.

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The association between diffuse-type beta -amyloid (AP) deposits and neuronal cell bodies in Alzheimer's disease (AD) and Down's syndrome (DS) could result from the secretion of AP from clusters of neurons in situ or the diffusion of A beta from cell processes, glial cells or blood vessels. To decide between these hypotheses, spatial pattern analysis was used to study the relationship between the degree of clustering of neuronal cell bodies and the presence of diffuse deposits in the temporal lobe of patients with DS. Significant clustering of neuronal cell bodies was present in 17/24 (71%) of brain areas studied. in addition, in 23/24 (96%) of brain areas, there was a positive correlation between the presence of diffuse deposits and the density of neurons. Hence, the data support the hypothesis that diffuse deposits develop in situ mainly as a result of the secretion of A beta by local clusters of neurons rather than by significant diffusion. Furthermore, the size of a diffuse deposit is likely to be determined by the number of neurons within a cluster which secrete A beta. The number and density of neurons could also be a factor determining the evolution of a diffuse into a mature amyloid deposit.

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The spatial patterns of diffuse, primitive and classic beta-amyloid (Abeta) deposits were studied in regions of the temporal lobe in cases of ‘pure’ Dementai with Lewy bodies (DLB), cases of DLB with associated Alzheimer’s disease (AD) (DLB/AD) and cases of ‘pure’ AD. Abeta deposits occurred in clusters in all patient groups. In the majority of brain areas studied, either a single large (=6400 micron) cluster of Abeta deposits was present or Abeta deposits occurred in smaller clusters which were regularly distributed parallel to the tissue boundary. No significant differences in the spatial patterns of Abeta deposits were observed in ‘pure’ DLB compared with DLB/AD. The spatial patterns of Abeta deposits in DLB/AD cases were generally similar to those observed in AD. However, in DLB/AD the primitive deposits occurred less often in a single large cluster and more often in smaller, regularly spaced clusters than in ‘pure’ AD. The data suggest a more specific pattern of degeneration associated with Abeta deposition in DLB/AD cases compared with ‘pure’ AD.

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Clustering of Pick bodies (PB) was studied in the frontal and temporal lobe in 10 cases of Pick's disease (PD). Pick bodies exhibited clustering in 47/50 (94%) brain areas analysed. In 20/50 (40%) brain areas, PB were present in a single large cluster ≤ 6400 μm in diameter, in 27/50 (54%) PB occurred in smaller clusters (200-3200 μm in diameter) which exhibited a regular periodicity relative to the tissue boundary, in 1/50 (2%) there was a regular distribution of individual PB and in 2/50 (4%), PB were randomly distributed. Mean cluster size of the PB was greater in the dentate gyrus compared with the inferior temporal gyrus and lateral occipitotemporal gyrus. Mean cluster size of PB in a brain region was positively correlated with the mean density of PB. Hence, PB exhibit essentially the same spatial patterns as senile plaques and neurofibrillary tangles in Alzheimer's disease (AD) and Lewy bodies in Dementia with Lewy bodies (DLB).

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The spatial patterns of Lewy bodies (LB), senile plaques (SP), and neurofibrillary tangles (NFT) were studied in ubiquitin-stained sections of the temporal lobe in cases of dementia with Lewy bodies (DLB), which varied in the degree of associated Alzheimer's disease (AD) pathology. In all patients, LB, SP, and NFT developed in clusters and in a significant proportion of brain areas, the clusters exhibited a regular periodicity parallel to the tissue boundary. In the lateral occipitotemporal gyrus (LOT) and parahippocampal gyrus (PHG), the clusters of LB were larger than those of the SP and NFT but in the hippocampus, clusters of the three lesions were of similar size. Mean cluster size of the LB, SP, and NFT was similar in cases of DLB with and without significant associated AD pathology. LB density was positively correlated with SP and NFT density in 42 and 17% of brain areas analyzed, respectively, while SP and NFT densities were positively correlated in 7% of brain areas. The data suggest that LB in DLB exhibit similar spatial patterns to SP and NFT in AD and that SP and NFT exhibit similar spatial patterns in DLB and AD. In addition, in some instances, clusters of LB appeared to be more closely related spatially to the clusters of SP than to NFT.

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Clustering of Lewy bodies (LB) was studied in four regions of the medial temporal lobe in 12 cases of dementia with LB (DLB). LB exhibited clustering in 67/70 (96%) brain areas analysed. In 34/70 (49%) analyses, LB were present in a single large cluster ≤6400 μm in diameter, in 33/70 (47%) LB occurred in smaller clusters 200-3200 μm in diameter which exhibited a regular periodicity relative to the tissue boundary and in 3/70 (4%), LB were randomly distributed. A regular pattern of LB clusters was observed equally frequently in the cortex and hippocampus, in upper and lower cortical laminae and in 'pure' cases of DLB with negligible Alzheimer's disease (AD) pathology compared with cases of AD with DLB. In cortical regions, there was no significant correlation between LB cluster size in the upper and lower cortical laminae. The regular periodicity of LB clusters suggests that LB develop in relation to the cells of origin of specific cortico-cortical and cortico-hippocampal projections.

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Immunostained preparations of the medial temporal lobe from patients with Down's syndrome (DS) were counterstained with cresyl violet to reveal the β-amyloid (Aβ) deposits and their associated cell populations. Aβ deposits in the cornu Ammonis (CA) of the hippocampus were, on average, more strongly stained, less often directly associated with neurons and more often associated with glial cells than the adjacent areas of cortex. Cored deposits were more frequently recorded in sulci rather than gyri and were associated with more glial cells than the uncored deposits. Multiple regression analyses suggested there was a positive correlation in the cortex between Aβ deposit size and the frequency of closely associated neurons, the correlation being most significant with larger (>25 μm) neurons. The morphology of Aβ deposit was also correlated with the location of deposits in the cortex, CA and dentate gyrus but this factor was of lesser importance. No significant variation in the morphology of the Aβ deposits was associated with the presence of blood vessels within or adjacent to the deposit. The data suggest that neuronal cell bodies are important in the initial formation of Aβ deposits and glial cells with the development of more mature amyloid deposits.

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β-amyloid (Aβ) deposition in the medial temporal lobe (MTL) was studied in elderly non-demented (ND) cases and in patients with Alzheimer's disease (AD). In AD, Aβ deposits were present throughout the MTL although density was less in the hippocampus than the adjacent cortical regions. In the ND cases, no Aβ deposits were recorded in 6 cases and in the remaining 8 cases, Aβ deposits were confined to the cortical regions adjacent to the hippocampus. The mean density of Aβ deposits in the cortical regions examined was greater in AD than in the ND cases but there was a significant overlap between the two groups. The ratio of mature to diffuse Aβ deposits was greater in the ND than the AD cases. In both patient groups, Aβ deposits formed clusters in the cortex and many tissues exhibited a regular distribution of clusters along the cortex parallel to the pia. The mean dimension of the Aβ clusters was greater in AD than in the ND cases. Hence, few aspects of Aβ deposition appeared to consistently separate AD from ND cases. However, the spread of Aβ pathology between modular units of the cortex and into regions of the hippocampus could be factors in the development of AD. © 1994.

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In Alzheimer's disease (AD) and Down's syndrome (DS), the size frequency distribution of the beta-amyloid (Abeta) deposits can be described by a log-normal model and may indictae the growth of the deposits. This study determined the size frequency distribution of the Abeta deposits in the temporal lobe in 8 casaes of dementia with Lewy bodies (DLB) with associated AD pathology (DLB/AD. The size distributions of Abeta deposits were unimodal and positively skewed; the mean size of deposi and the degree of skew varying with deposit type and brain region. Size distributions of the primitive deposits had lower means and were less skewed compared with the diffuse and classic deposits. In addition, size distributions in the hippocampus and parahippocampal gyrus (PHG) had larger means and a greater degree of skew compared with other cortical gyri. All size distributions deviated significantly from a log-normal model. There were more Abeta deposits than expected in the smaller size classes and fewer than expected near the mean and in the larger size classes. The data suggest thatthe pattern of growth of the Abeta deposits in DLB/AD depends both on deposit morphology and brain area. In addition, Abeta deposits in DLB appear to grow to within a more restricted size range than predicted and hence, to have less potential for growth compared with cases of 'pure' AD and DS.

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The spatial distribution patterns of the diffuse, primitive, and classic beta-amyloid (Abeta) deposits were studied in areas of the medial temporal lobe in 12 cases of Down's Syndrome (DS) 35 to 67 years of age. Large clusters of diffuse deposits were present in the youngest patients; cluster size then declined with patient age but increased again in the oldest patients. By contrast, the cluster sizes of the primitive and classic deposits increased with age to a maximum in patients 45 to 55 and 60 years of age respectively and declined in size in the oldest patients. In the parahippocampal gyrus (PHG), the clusters of the primitive deposits were most highly clustered in cases of intermediate age. The data suggest a developmental sequence in DS in which Abeta is deposited initially in the form of large clusters of diffuse deposits that are then gradually replaced by clusters of primitive and classic deposits. The oldest patients were an exception to this sequence in that the pattern of clustering resembled that of the youngest patients.

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The spatial patterns of Pick bodies (PB), Pick cells (PC), senile plaques (SP) and neurofibrillary tangles (NFT) were studied in the frontal and temporal lobe in nine cases of Pick’s disease (PD). Pick bodies exhibited clustering in 41/44 (93%) of analyses and clusters of PB were regularly distributed parallel to the tissue boundary in 24/41 (58%) of analyses. Pick cells exhibited clustering with regular periodicity of clusters in 14/16 (88%) analyses, SP in three out of four (75%) analyses and NFT in 21/27 (78%) analyses. The largest clusters of PB were observed in the dentate gyrus and PC in the frontal cortex. In 10/17 (59%) brain areas studied, a positive or negative correlation was observed between the densities of PB and PC. The densities of PB and NFT were not significantly correlated in the majority of brain areas but a negative correlation was observed in 7/29 (24%) brain areas. The data suggest that PB and PC in patients with PD exhibit essentially the same spatial patterns as SP and NFT in Alzheimer’s disease (AD) and Lewy bodies (LB) in dementia with Lewy bodies (DLB). In addition, there was a spatial correlation between the clusters of PB and PC, suggesting a pathogenic relationship between the two lesions. However, in the majority of tissues examined there was no spatial correlation between the clusters of PB and NFT, suggesting that the two lesions develop in association with different populations of neurons.

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The size frequency distributions of diffuse, primitive and cored senile plaques (SP) were studied in single sections of the temporal lobe from 10 patients with Alzheimer’s disease (AD). The size distribution curves were unimodal and positively skewed. The size distribution curve of the diffuse plaques was shifted towards larger plaques while those of the neuritic and cored plaques were shifted towards smaller plaques. The neuritic/diffuse plaque ratio was maximal in the 11 – 30 micron size class and the cored/ diffuse plaque ratio in the 21 – 30 micron size class. The size distribution curves of the three types of plaque deviated significantly from a log-normal distribution. Distributions expressed on a logarithmic scale were ‘leptokurtic’, i.e. with excess of observations near the mean. These results suggest that SP in AD grow to within a more restricted size range than predicted from a log-normal model. In addition, there appear to be differences in the patterns of growth of diffuse, primitive and cored plaques. If neuritic and cored plaques develop from earlier diffuse plaques, then smaller diffuse plaques are more likely to be converted to mature plaques.

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The spatial patterns of diffuse, primitive, classic and compact beta-amyloid (Abeta) deposits were studied in the medial temporal lobe in 14 elderly, non-demented patients (ND) and in nine patients with Alzheimer’s disease (AD). In both patient groups, Abeta deposits were clustered and in a number of tissues, a regular periodicity of Abeta deposit clusters was observed parallel to the tissue boundary. The primitive deposit clusters were significantly larger in the AD cases but there were no differences in the sizes of the diffuse and classic deposit clusters between patient groups. In AD, the relationship between Abeta deposit cluster size and density in the tissue was non-linear. This suggested that cluster size increased with increasing Abeta deposit density in some tissues while in others, Abeta deposit density was high but contained within smaller clusters. It was concluded that the formation of large clusters of primitive deposits could be a factor in the development of AD.