Understanding the Link Between White Matter Abnormalities and Schizophrenia Symptoms
Understanding the Link Between White Matter Abnormalities and Schizophrenia Symptoms
A new study using brain imaging shows that people with schizophrenia have abnormalities in their white matter that correlate with psychosis, as well as cognitive impairment and other behavioral symptoms. White matter is found in the brain and spinal cord and is made up of nerve fibers covered in myelin sheaths. Myelin is a mixture of protein and fats that creates an insulating sheath around nerves, much like the rubber covering that insulates electrical wires. It helps conduct information quickly through the central nervous system.
Past research has clearly shown white matter irregularities in schizophrenia, but the connection with symptoms patients experience has remained unclear.
To investigate further, a research team led by 1997 and 2000 NARSAD Young Investigator Juan R. Bustillo, M.D., a psychiatrist at the University of New Mexico in Albuquerque, used two specialized types of MRI brain imaging: diffusion tensor imaging and proton spectroscopic imaging. Diffusion tensor imaging allows researchers to see white matter at high resolution. Proton spectroscopic imaging allows scientists to identify protein products called metabolites that are generated by living brain cells.
By examining the imaging results of 64 people with schizophrenia and 64 healthy controls, the researchers concluded that in the brains of people with schizophrenia, there was a lowered density of axons (the threadlike “wires” that connect neurons), an increased number of glial cells (so-called helper cells that maintain and support neurons), and more myelination. The results appeared online March 18th in Neuropsychopharmacology.
These and other results of the imaging studies suggest that myelination in the white matter of patients with the most severe psychotic symptoms is above normal. The results also suggest that the white matter is altered in these patients as well in as those suffering mainly from cognitive impairment and other behavioral symptoms. Dr. Bustillo and his colleagues speculate that the brain adapts to the changes that occur in schizophrenia over time by increasing myelination in certain parts of the brain.
