Lateralization of epileptiform discharges in patients with epilepsy and precocious destructive brain insults

Unilateral destructive brain lesions of early development can result in compensatory thickening of the ipsilateral cranial vault. The aim of this study was to determine the frequency of these bone changes among patients with epilepsy and precocious destructive lesions, and whether a relationship exists between these changes and epileptiform discharges lateralization. Fifty-one patients had their ictal/inter-ictal scalp EEG and skull thickness symmetry on MRI analyzed. Patients were divided into three main groups according to the topographic distribution of the lesion on the MRI: hemispheric (H) (n=9); main arterial territory (AT) (n=25); arterial borderzone (Bdz) (n=17). The EEG background activity was abnormal in 26 patients and were more frequent among patients of group H (p=0.044). Thickening of the skull was more frequent among patients of group H (p=0.004). Five patients (9.8%) showed discordant lateralization between epileptiform discharges and structural lesion (four of them with an abnormal background, and only two of them with skull changes). in one of these patients, ictal SPECT provided strong evidence for scalp EEG false lateralization. The findings suggest that compensatory skull thickening in patients with precocious destructive brain insults are more frequent among patients with unilateral and large lesions. However, EEG lateralization discordance among these patients seems to be more related to EEG background abnormalities and extent of cerebral damage than to skull changes.6211

Host genotype and time dependent antigen presentation of viral peptides: predictions from theory

The rate of progression of HIV infected individuals to AIDS is known to vary with the genotype of the host, and is linked to their allele of human leukocyte antigen (HLA) proteins, which present protein degradation products at the cell surface to circulating T-cells. HLA alleles are associated with Gag-specific T-cell responses that are protective against progression of the disease. While Pol is the most conserved HIV sequence, its association with immune control is not as strong. To gain a more thorough quantitative understanding of the factors that contribute to immunodominance, we have constructed a model of the recognition of HIV infection by the MHC class I pathway. Our model predicts surface presentation of HIV peptides over time, demonstrates the importance of viral protein kinetics, and provides evidence of the importance of Gag peptides in the long-term control of HIV infection. Furthermore, short-term dynamics are also predicted, with simulation of virion-derived peptides suggesting that efficient processing of Gag can lead to a 50% probability of presentation within 3 hours post-infection, as observed experimentally. In conjunction with epitope prediction algorithms, this modelling approach could be used to refine experimental targets for potential T-cell vaccines, both for HIV and other viruses

Epilepsy and destructive brain insults in early life: a topographical classification on the basis of MRI findings

Destructive insults of early development can lead to a wide variety of lesional patterns and are a wet[ known cause of epilepsy. The aim of this study is to present a topographic magnetic resonance imaging (MRI) classification of these lesions in adult patients with epilepsy. Thirty-three consecutive patients were divided in three groups according to the topographic distribution of their Lesion on MRI: hemispheric (H, n = 7); main arterial territory (AT, n = 18); arterial borderzone (Bdz, n = 8). We analyzed clinical, MRI and magnetic resonance angiography (MRA) data. Status epilepticus (SE) during childhood was more common in group H (7/7) than in the groups AT (1/18) and Bdz (0/8) (P < 0.001). MRA pattern of impaired flow signal in the distal segments of at[ three major arteries in the affected hemisphere was present in 85.7% of group H patients, and was exclusive to this group. 88.8% (16/18) of patients from group AT presented congenital motor deficit, in contrast to 37.5% (3/8) of group Bdz, and in none of group H (P < 0.001). All patients with Bdz Lesions had antecedent of fetal distress, in contrast to 1/7 from group H and 5/18 of group AT (P = 0.001). The MRAs of patients with Bdz lesions were often normal except in those with larger lesions. Our data suggest that in adult patients with epilepsy due to precocious destructive brain insults, a MRI topographical classification distributes them in relatively homogenous clinical groups. (C) 2003 BEA Treading Ltd. Published by Elsevier Ltd. All rights reserved.13638339

Crossed cerebellar atrophy in patients with precocious destructive brain insults

Objective: To analyze the frequency and pathogenetic factors of crossed cerebellar atrophy (CCA) in adult patients with epilepsy secondary to destructive brain insults of early development. Methods: We studied 51 adult patients with epilepsy and precocious destructive lesions. Patients were divided into 3 groups according to the topographic distribution of their lesions on magnetic resonance imaging: group A, hemispheric (n = 9); group B, main arterial territory (n = 25); and group C, arterial border zone (n= 17). We evaluated the presence of CCA visually and with cerebellar volumetric measurement, correlating it with the clinical data. Other features shown on magnetic resonance imaging, such as the thalamus, brainstem, and middle cerebellar peduncle, were also carefully analyzed. Results: Seven patients (13%) had CCA that was associated with the extent of the supratentorial lesion (6 from group A, 1 from group B, and none from group C; P<.001). Status epilepticus was present in 6 patients from group A and in none from the other groups. There was an association between the antecedent of status epilepticus and CCA (P<.001). All patients had atrophy of the cerebral peduncle ipsilateral to the supratentorial lesion and 4 had contralateral atrophy of the middle cerebellar peduncle, The duration of epilepsy was not associated with the presence of CCA (P = .20). Conclusions: Our data suggest that in patients with epilepsy and destructive insults early in life, the extent of the supratentorial lesion as well as the antecedent of status epilepticus play a major role in the pathogenesis of CCA. Recurrent seizures do not seem to be relevant to the development of CCA.59584384

Is human immunodeficiency virus/acquired immunodeficiency syndrome decreasing among Brazilian injection drug users? Recent findings and how to interpret them

We briefly review findings from Brazilian settings where the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic among injection drug users (IDUs) seems to be decreasing, highlighting recent findings from Rio de Janeiro and discussing methodological alternatives. Former analyses using serologic testing algorithm for recent HIV seroconversion have shown that HIV incidence has been low in IDUs recruited by two different surveys carried out in Rio, where low injection frequencies and infection rates have been found among new injectors. The proportion of AIDS cases among IDUs in Rio has been fairly modest, compared to São Paulo and especially to the southernmost states. Notwithstanding, the interpretation of findings from serial surveys constitutes a challenge, magnified in the assessment of HIV spread among IDUs due to the dynamic nature of the drug scenes and limitations of sampling strategies targeting hard-to-reach populations. Assessment of epidemic trends may profit from the triangulation of data, but cannot avert biases associated with sampling errors. Efforts should be made to triangulate data from different sources, besides exploring specific studies from different perspectives. In an attempt to further assess the observed trends, we carried out original analyses using data from Brazilian AIDS databank