Article

Anterior limb of the internal capsule in schizophrenia: A diffusion tensor tractography study

Psychiatry Neuroimaging Laboratory, Department of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston Street, Boston, MA 02215, USA.
Brain Imaging and Behavior (Impact Factor: 4.6). 03/2012; 6(3):417-25. DOI: 10.1007/s11682-012-9152-9
Source: PubMed

ABSTRACT Thalamo-cortical feedback loops play a key role in the processing and coordination of processing and integration of perceptual inputs and outputs, and disruption in this connection has long been hypothesized to contribute significantly to neuropsychological disturbances in schizophrenia. To test this hypothesis, we applied diffusion tensor tractography to 18 patients suffering schizophrenia and 20 control subjects. Fractional anisotropy (FA) was evaluated in the bilateral anterior and posterior limbs of the internal capsule, and correlated with clinical and neurocognitive measures. Patients diagnosed with schizophrenia showed significantly reduced FA bilaterally in the anterior but not the posterior limb of the internal capsule, compared with healthy control subjects. Lower FA correlated with lower scores on tests of declarative episodic memory in the patient group only. These findings suggest that disruptions, bilaterally, in thalamo-cortical connections in schizophrenia may contribute to disease-related impairment in the coordination of mnemonic processes of encoding and retrieval that are vital for efficient learning of new information.

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Available from: Martha E Shenton, Dec 19, 2013
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    • "Internal capsule VBM Kubicki et al., 2005; Buchsbaum et al., 2006; Munoz Maniega et al., 2008; Skelly et al., 2008; Sussmann et al., 2009; Nakamura et al., 2012; Levitt et al., 2012 Tractography Oh et al., 2009; Rosenberger et al., 2012 TBSS Seal et al., 2008; Knochel et al., 2012 Cortico-spinal tract TBSS Knochel et al., 2012 Tractography de Weijer et al., 2011 Corona radiata VBM Cui et al., 2011 TBSS Fujino et al., 2014 Middle cerebellar peduncles VBM Okugawa et al., 2004 tracts being affected, there is more likely an array of subtly altered networks distributed throughout the brain. Nevertheless, it could also be argued that the data suggest that the connectivity of frontal regions is particularly affected. "
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    Frontiers in Human Neuroscience 08/2014; 8:653. DOI:10.3389/fnhum.2014.00653 · 2.90 Impact Factor
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    • "The ALIC contains fibers connecting the thalamus to frontal lobe and corticopontine fibers (Rosenberger et al., 2012). Bilateral reductions in fractional anisotropy (FA) and increases in radial diffusivity (RD) have been reported in the ALIC of individuals with schizophrenia (Levitt et al., 2010; Rosenberger et al., 2012), and have been associated with prefrontal-based neuropsychological impairments such as episodic memory (Levitt et al., 2010). The fornix connects the hippocampus to subcortical structures, including mammillary bodies, anterior nucleus of the thalamus, nucleus accumbens, and ventral tegmental area, as well as prefrontal cortex. "
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