Biomedical subjects

Tom F Nugent

Publications and source records attributed to Tom F Nugent.

4 recordsLinked to original sources

PubMed2006

Dynamic mapping of hippocampal development in childhood onset schizophrenia.

Prior cross-sectional anatomic brain imaging studies of the hippocampus in schizophrenia have generally shown loss in total hippocampal volume although the progressive course of these changes remains unknown. We report the first prospective sub-regional maps of hippocampal development in childhood onset schizophrenia (COS), reconstructed from serial brain MRI scans of 29 children with COS scanned every 2 years (87 scans) and compared to 31 controls matched for age, sex, and scan interval (94 scans). As expected, the COS subjects showed significant bilateral deficits (9-10%) in total hippocampal volume which remained consistent between age 9 and 26. However sub-regional maps showed heterogeneous changes with loss of hippocampal volume in both anterior as well as posterior ends while the body of the hippocampus gained in volume suggesting that hippocampal subunits are differentially affected in schizophrenia.

Adolescent↗

PubMed2006

Dynamic mapping of normal human hippocampal development.

The hippocampus, which plays an important role in memory functions and emotional responses, has distinct subregions subserving different functions. Because the volume and shape of the hippocampus are altered in many neuropsychiatric disorders, it is important to understand the trajectory of normal hippocampal development. We present the first dynamic maps to reveal the anatomical sequence of normal human hippocampal development. A novel hippocampal mapping technique was applied to a database of prospectively obtained brain magnetic resonance imaging (MRI) scans (100 scans in 31 children and adolescents), scanned every 2 yr for 6-10 yr between ages 4 and 25. Our results establish that the structural development of the human hippocampus is remarkably heterogeneous, with significant differences between posterior (increase over time) and anterior (loss over time) subregions. These distinct developmental trajectories of hippocampal subregions may parallel differences in their functional development.

Adolescent↗

PubMed2004

Dynamic mapping of human cortical development during childhood through early adulthood.

We report the dynamic anatomical sequence of human cortical gray matter development between the age of 4-21 years using quantitative four-dimensional maps and time-lapse sequences. Thirteen healthy children for whom anatomic brain MRI scans were obtained every 2 years, for 8-10 years, were studied. By using models of the cortical surface and sulcal landmarks and a statistical model for gray matter density, human cortical development could be visualized across the age range in a spatiotemporally detailed time-lapse sequence. The resulting time-lapse "movies" reveal that (i) higher-order association cortices mature only after lower-order somatosensory and visual cortices, the functions of which they integrate, are developed, and (ii) phylogenetically older brain areas mature earlier than newer ones. Direct comparison with normal cortical development may help understanding of some neurodevelopmental disorders such as childhood-onset schizophrenia or autism.

Adolescent↗

PubMed2004

Comparison of progressive cortical gray matter loss in childhood-onset schizophrenia with that in childhood-onset atypical psychoses.

BACKGROUND: Recent anatomical brain magnetic resonance imaging (MRI) studies show a striking postpsychotic progressive loss of cortical gray matter (GM) in patients with childhood-onset schizophrenia (COS), which appears greater than that seen for adult patients. However, the diagnostic specificity and the relationship of these changes to drug treatment and cognitive functioning remain unclear. We performed a comparative prospective brain MRI study in patients with COS and pediatric patients with transient psychosis with behavior problems (psychosis not otherwise specified) provisionally considered multidimensionally impaired (MDI). We hypothesized that cortical GM loss would occur in patients with COS but not in adolescents with atypical psychoses. METHODS: Anatomical brain MRI was performed at baseline and follow-up in 19 patients in the MDI group (mean [SD] age of 13.3 [3.1] years); in 23 patients with COS matched for age, sex, IQ score, and drug treatment (mean [SD] age of 13.9 [2.5] years); and 38 healthy control subjects matched for age and sex (mean [SD] age of 13.3 [3.1] years). The mean (SD) follow-up was 2.5 (0.8) years. Volumes of the cerebrum and total and regional GM were obtained by using automated analysis, and percent change in volume across time was calculated. One-way analyses of variance with post hoc Tukey Honestly Significantly Different comparisons were performed to examine group differences in the percent change in GM across follow-up. RESULTS: The COS group had significantly greater total, frontal, temporal, and parietal GM loss than did the MDI or healthy control groups; analysis of variance post hoc P values ranged from.03 to.001. The MDI and control groups did not differ significantly from each other. CONCLUSIONS: The cortical GM volume loss in COS appears diagnostically specific; it was not seen in children and adolescents with atypical psychosis. Because both patient groups had similar early developmental patterns, cognitive functioning, medications, and hospitalizations, this progressive loss appears to be intrinsic to COS. An ongoing neurodevelopmental process and/or brain response specific to the illness could account for these changes.

Adolescent↗