White matter research sheds light on schizophrenia
6 July 2007
An important international study has identified 'white matter' abnormalities in the brain as an underlying cause of the symptoms of schizophrenia.
Dr Thomas Whitford, from the University of Sydney's Brain Dynamics Centre based at the Westmead Millennium Institute, studied white matter abnormalities in patients with first episode schizophrenia, and looked at whether there was progressive white matter pathology in the disease.
White matter is one of the two main solid components of the central nervous system. It is composed of myelinated nerve cell processes, or axons, which connect various gray matter areas (the locations of nerve cell bodies) of the brain to each other and carry nerve impulses between neurons.
'Volumetric White Matter Abnormalities in First-Episode Schizophrenia; A Longitudinal, Tensor-Based Morphometry Study', published in the American Journal of Psychiatry this month, includes analysis of MRI scans on 41 patients with first episode schizophrenia, 25 of whom returned for a second scan between 2 and 3 years later.
The first-episode schizophrenia patents exhibited volumetric deficits in the white matter of the frontal and temporal lobes at baseline, as well as volumetric increases in the white matter of the frontoparietal junction bilaterally.
"We also found these patients lost considerably more white matter over the follow-up interval, relative to comparison subjects in the middle and inferior temporal cortex bilaterally," said Dr Whitford.
While schizophrenia has long been considered to be a disorder of brain connectivity, few studies have investigated white matter abnormalities in patients with first episode schizophrenia. Even fewer studies have investigated whether there is progressive white matter pathology in the disease.
"Given the role that white matter plays in connecting disparate regions of neural tissues and in modulating the transmission velocities of action potentials, volumetric white matter abnormalities, as have been reported in the present study, could be expected to result in a dysfunction in neural communication," said Dr Whitford.
"The fact that we observed the white matter of the frontal and temporal lobes to be especially affected in patents with first-episode schizophrenia adds support to theories that have argued that a breakdown in frontal temporal connectivity as being the underlying cause of schizophrenia."
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