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Task performance and cerebral activation during a simple motor task: a study with functional Magnetic Resonance Imaging
Abstracts / Psychiatry Research: Neuroirnaging68 (1997) 155-184 non-emotional control conditions. Regions of interest were placed on MR1 scans and transposed onto the corresponding PET images. Against a pattern of generalized activation were lateralized and valence specific effects of mood on rCBF for subcortical, but not for other regions. During the sad mood induction condition, rCBF increased in the left amygdala, and decreased in the right amygdala, respectively. These lateralized changes correlated with shifts toward negative affect. Correlations were opposite for subcortical (negative affect associated with lower left hemispheric CBF) compared to the frontal-temporal cortical regions. The findings suggest a reciprocity between the subcortical and the frontal-temporal regulation of emotional experience. Study two: fMR1 (BOLD method). Changes in regional cerebral blood oxygenation during experimentally modified psychological activation can also be measured with functional magnetic resonance imaging (fMRI). In this study with 12 right handed normals a T2*FLASH sequence was used to investigate changes within the temporal lobe and especially in the amygdala during experimentally induced emotions (same design as Study one). In agreement with the previous PET study, a significant increase in SI in the left amygdala was found during sad mood induction. Such converging evidence is needed for advancing the understanding of neural substrates for emotional experience. Task performance and cerebral activation during a simple motor task: a study with functional Magnetic Resonance Imaging J. Schr6der ~, K. Baudendistel b, M. Essig h, L.R. Schad h, F. Wenz b, M.V. Knopp b, Th. Jahn c
aDepartment of Psychiatry, University of Heidelberg, Germany. bGerrnan Cancer Research Center, Heidelberg, Germany. CDepartment of Psychology, University of Konstanz, Germany Repetitive motor tasks are widely used paradigms in neuroimaging studies. However, the relation between task performance and brain activation remains largely unclear, since motor task performance has only been rated on clinical grounds. The aim of the present study was to monitor task performance during functional magnetic resonance image (fMRI) acquisition. Ten healthy, right-handed volunteers were included. Using a 1.5T Siemens Magnetom fMRl were obtained under pronation/supination and in a resting condition. To monitor motor performance a pronation/supination device was adapted to the fMRI environment. Probands were asked to pronate/supinate their forearm according to the pace given by a metronom. All probands were able to keep the pace. Pronation/supination led to a significant activation of the contralatera| and ipsilateral sensorimotor cortices and the supplementary motor area (SMA). With accelerated speed a significant increased activation of the right (d.f. = 2; F = 3.48; P < 0.05), but not left (d.f. = 2; F = 1.19; P = 0.32) sensorimotor cortex was observed. On both hemispheres, contralateral pronation/supination (d.f. = 1; F = 20.07; P < 0.0001) induced a significantly g r e a t e r activation than ipsilateral pronation/supination (d.f. 1; F = 40.36; P < 0.0001). Regarding the SMA, a significant velocity effect was not observed.
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Our study provides two findings: first, further evidence that contralateral movement leads to greater activation than ipsilateral movement; and second, an indication that right sensorimotor cortex activation increases with accelerating speed. That this effect did not apply to the left sensorimotor cortex may be related to the experimental situation where speed was externally driven by a metronom. Quantitative Magnetic Resonance Imaging and neuropsychological functions in AIzheimer's disease J. Schr6der a, J. Pantel a, L. R. Schad b, M. Friedlinger b, M.V. Knopp b, R. Schmitt a, M. Essig b, H. Sauer c
aDepartment of Psychiatry, Section of Geriatric Psychiatry, University of Heidelberg, Germany. bDepartment of Radiology, German Center of Cancer Research (DKFZ), Heidelberg, Germany, CDepartment of Psychiatry, Universityof Jena, Germany The aim of the present study was to investigate neuropsychological performance in dementia of the Alzheimer type (DAT) with respect to morphological changes that were revealed by quantitative magnetic resonance imaging (MRI). Twenty-two patients with DAT (NINCDS-ADRDA guidelines) and 10 healthy controls were included. Neuropsychological functions were evaluated on a test battery covering severity of dementia, memory functions, concentration and attention, language skills as well as activities of daily living. 3D MRi sequences were acquired using a 1.5 T Siemens MAGNETOM. Whole brain volume, total intracranial volume (TIV), volumes of the frontal and temporal lobes and volumes of the amygdalahippocampus complex (AHC) were assessed using the newly developed software NMRWin. This software provides a semiautomated measure of the whole brain volume, while measurements of substructures have to be done manually. Measurements were performed by two independent raters (interrater reliability: r = 0.95-0.96, P < 0.0001) on a conventional 486 PC. The volumetric data were corrected for head size by dividing the absolute values by the TIV. Apart from the TIV all corrected morphometric parameters differed significantly between the diagnostic groups. AHC volumes discriminated best between the groups, with only a relatively small overlap. AHC atrophy exceeded generalized atrophy. These findings were confirmed when the data were re-analyzed after dividing the DAT patients into a mildly and moderately affected group. Severity of dementia correlated with the volumes of the AHC and the temporal lobes bilaterally, but neither with the wholc brain volume nor the volumes of the frontal lobes. No dear relationships between specific cognitive disabilities and singlc anatomic variables were found. These results underline the important role of the temporal substructures in thc etiology and progression of DAT. They indicate that the volume of the AHC can be monitored by MRI and may bc uscd to lollow up the disease proccss. EEG-power in schizophrenics correlates with psychopathology, brain morphology and psychometry A, Schwarz a, U. Pester ~, J. Lerche ~', T, lsensce ~, S. Kropf b, M. Brosz b, C. Wurthmann ~, P, Danos ~', B. Bogerts ~'
aDepartment of Psychiatry, University of Heidelberg, Germany. bGerrnan Cancer Research Center, Heidelberg, Germany. CDepartment of Psychology, University of Konstanz, Germany Repetitive motor tasks are widely used paradigms in neuroimaging studies. However, the relation between task performance and brain activation remains largely unclear, since motor task performance has only been rated on clinical grounds. The aim of the present study was to monitor task performance during functional magnetic resonance image (fMRI) acquisition. Ten healthy, right-handed volunteers were included. Using a 1.5T Siemens Magnetom fMRl were obtained under pronation/supination and in a resting condition. To monitor motor performance a pronation/supination device was adapted to the fMRI environment. Probands were asked to pronate/supinate their forearm according to the pace given by a metronom. All probands were able to keep the pace. Pronation/supination led to a significant activation of the contralatera| and ipsilateral sensorimotor cortices and the supplementary motor area (SMA). With accelerated speed a significant increased activation of the right (d.f. = 2; F = 3.48; P < 0.05), but not left (d.f. = 2; F = 1.19; P = 0.32) sensorimotor cortex was observed. On both hemispheres, contralateral pronation/supination (d.f. = 1; F = 20.07; P < 0.0001) induced a significantly g r e a t e r activation than ipsilateral pronation/supination (d.f. 1; F = 40.36; P < 0.0001). Regarding the SMA, a significant velocity effect was not observed.
175
Our study provides two findings: first, further evidence that contralateral movement leads to greater activation than ipsilateral movement; and second, an indication that right sensorimotor cortex activation increases with accelerating speed. That this effect did not apply to the left sensorimotor cortex may be related to the experimental situation where speed was externally driven by a metronom. Quantitative Magnetic Resonance Imaging and neuropsychological functions in AIzheimer's disease J. Schr6der a, J. Pantel a, L. R. Schad b, M. Friedlinger b, M.V. Knopp b, R. Schmitt a, M. Essig b, H. Sauer c
aDepartment of Psychiatry, Section of Geriatric Psychiatry, University of Heidelberg, Germany. bDepartment of Radiology, German Center of Cancer Research (DKFZ), Heidelberg, Germany, CDepartment of Psychiatry, Universityof Jena, Germany The aim of the present study was to investigate neuropsychological performance in dementia of the Alzheimer type (DAT) with respect to morphological changes that were revealed by quantitative magnetic resonance imaging (MRI). Twenty-two patients with DAT (NINCDS-ADRDA guidelines) and 10 healthy controls were included. Neuropsychological functions were evaluated on a test battery covering severity of dementia, memory functions, concentration and attention, language skills as well as activities of daily living. 3D MRi sequences were acquired using a 1.5 T Siemens MAGNETOM. Whole brain volume, total intracranial volume (TIV), volumes of the frontal and temporal lobes and volumes of the amygdalahippocampus complex (AHC) were assessed using the newly developed software NMRWin. This software provides a semiautomated measure of the whole brain volume, while measurements of substructures have to be done manually. Measurements were performed by two independent raters (interrater reliability: r = 0.95-0.96, P < 0.0001) on a conventional 486 PC. The volumetric data were corrected for head size by dividing the absolute values by the TIV. Apart from the TIV all corrected morphometric parameters differed significantly between the diagnostic groups. AHC volumes discriminated best between the groups, with only a relatively small overlap. AHC atrophy exceeded generalized atrophy. These findings were confirmed when the data were re-analyzed after dividing the DAT patients into a mildly and moderately affected group. Severity of dementia correlated with the volumes of the AHC and the temporal lobes bilaterally, but neither with the wholc brain volume nor the volumes of the frontal lobes. No dear relationships between specific cognitive disabilities and singlc anatomic variables were found. These results underline the important role of the temporal substructures in thc etiology and progression of DAT. They indicate that the volume of the AHC can be monitored by MRI and may bc uscd to lollow up the disease proccss. EEG-power in schizophrenics correlates with psychopathology, brain morphology and psychometry A, Schwarz a, U. Pester ~, J. Lerche ~', T, lsensce ~, S. Kropf b, M. Brosz b, C. Wurthmann ~, P, Danos ~', B. Bogerts ~'