Biomedical subjects

J G Csernansky

Publications and source records attributed to J G Csernansky.

130 records · Page 8Linked to original sources

PubMedDate not supplied

Structural MRI as a tool for the study of neurotoxicity and neurodegenerative disorders.

High-resolution magnetic resonance (MR) imaging affords an unprecedented opportunity to study the severity and distribution of neurodegenerative changes in the human brain. By selecting specific MR sequence parameters (i.e., TE and TR), different MR signals can be received from different tissue types, such as gray and white matter. Through optimization of the contrast between different tissue types, the surfaces and internal structures of brain structures of special interest can be visualized and quantitated. Metrics such as two-dimensional areas, three-dimensional volumes, and three-dimensional shape characteristics have proven to be highly useful for quantitating the effects of toxins on the human brain. Among toxins, the effects of alcohol on the human brain have been most intensively studied using structural MR imaging. Volume losses in the cerebral cortex and other brain regions of interest have been carefully quantitated. However, because exposure to alcohol is almost always repeated over many years, the effects of normal aging must be carefully considered when making comparisons between diseased and healthy populations. In contrast to the literature on alcohol, structural MR imaging has been relatively underutilized in the study of drugs and other chemicals such as MPTP and other drugs of abuse that are toxic to special populations of neurons. However, as the resolution of structural MR continues to improve, the structural characteristics of such neuron populations will be visualized and quantitated, and successful use of structural MR imaging for the study of such toxins will become possible.

Alcohol Drinking↗

PubMedDate not supplied

Neuroendocrinology and limbic epilepsy: relationships to psychopathology, seizure variables, and neuropsychological function.

Correlations were sought among neuroendocrine, psychopathologic, neuropsychological, and seizure variables in 16 male patients with limbic epilepsy. Plasma prolactin and luteinizing hormone levels were directly correlated with seizure frequency. Plasma prolactin was inversely correlated with thought disorder. Post hoc findings included a strong direct correlation between total plasma testosterone levels and aggression. These relationships may help to elucidate mechanisms related to interictal symptomatology in patients with limbic epilepsy.

Epilepsy↗

PubMedDate not supplied

Psychopathology and limbic epilepsy: relationship to seizure variables and neuropsychological function.

Correlations were sought among psychopathologic, neuropsychological, and seizure variables in 21 patients with limbic epilepsy. Observer-based assessments, such as the Bear-Fedio Inventory, and self-report assessments of psychopathology were used. Self-reported psychotic experiences were associated with increased seizure frequency. Increased religiosity was noted in patients whose epileptic focus included the left side. Increased neuropsychological impairment was associated with several measures of psychopathology, including those related to thought disorder, psychoticism, and affective disturbance.

Epilepsy↗

PubMedDate not supplied

Predictive value of hippocampal MR imaging-based high-dimensional mapping in mesial temporal epilepsy: preliminary findings.

BACKGROUND AND PURPOSE: We objectively assessed surface structural changes of the hippocampus in mesial temporal sclerosis (MTS) and assessed the ability of large-deformation high-dimensional mapping (HDM-LD) to demonstrate hippocampal surface symmetry and predict group classification of MTS in right and left MTS groups compared with control subjects. METHODS: Using eigenvector field analysis of HDM-LD segmentations of the hippocampus, we compared the symmetry of changes in the right and left MTS groups with a group of 15 matched controls. To assess the ability of HDM-LD to predict group classification, eigenvectors were selected by a logistic regression procedure when comparing the MTS group with control subjects. RESULTS: Multivariate analysis of variance on the coefficients from the first 9 eigenvectors accounted for 75% of the total variance between groups. The first 3 eigenvectors showed the largest differences between the control group and each of the MTS groups, but with eigenvector 2 showing the greatest difference in the MTS groups. Reconstruction of the hippocampal deformation vector fields due solely to eigenvector 2 shows symmetrical patterns in the right and left MTS groups. A "leave-one-out" (jackknife) procedure correctly predicted group classification in 14 of 15 (93.3%) left MTS subjects and all 15 right MTS subjects. CONCLUSION: Analysis of principal dimensions of hippocampal shape change suggests that MTS, after accounting for normal right-left asymmetries, affects the right and left hippocampal surface structure very symmetrically. Preliminary analysis using HDM-LD shows it can predict group classification of MTS and control hippocampi in this well-defined population of patients with MTS and mesial temporal lobe epilepsy (MTLE).

Adult↗