Schizophrenia may be disorder of brain connectivity
MedWire News: Results from an imaging study show that patients with schizophrenia have abnormalities in connective structures between the hippocampus and cortex, supporting the hypothesis that the disorder is associated with brain connectivity disruption.
"Disruptions in the hippocampal-cortical functional connectivities have been implicated in schizophrenia but less is known about their anatomical disconnectivities and association with clinical symptoms," explain A Qiu and colleagues from the National University of Singapore.
To investigate further, the team studied 126 patients with schizophrenia and 77 age- and gender-matched mentally healthy control individuals.
Magnetic resonance imaging and diffusion tensor imaging scans, together with brain-mapping techniques, were used to assess and compare hippocampal shape, cortical thickness, and integrity of white matter bundles connecting these brain areas.
The researchers found that, compared with controls, schizophrenic patients had inward-surface deformities in bilateral anterior hippocampi, and cortical thinning in bilateral prefrontal, temporal, and occipital cortices.
In addition, in the patients with schizophrenia, deformities in the shape of the anterior hippocampus were associated with cortical thinning in the brain regions involved in visuospatial and verbal memory pathways.
Compared with controls, reduced fractional anisotropy in the fornix and cingulum white matter bundles in schizophrenic patients indicated abnormal integration of white matter between the hippocampus and cortex.
The researchers also found that greater disruptions in hippocampal-cortical connectivity were associated with more severe negative symptoms in schizophrenia patients.
Qiu and team conclude in the journal NeuroImage: "Our findings suggested that aberrant structural hippocampal-cortical connectivities may serve as a marker of the illness and provide further structural evidence to support the notion of schizophrenia as a disorder of brain connectivity."
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By Mark Cowen