Proton magnetic resonance spectroscopic imaging of cortical gray and white matter in schizophrenia.
OBJECTIVE
To apply in vivo proton magnetic resonance spectroscopy imaging estimates of N-acetylaspartate (NAA), a neuronal marker, to clarify the relative contribution of neuronal and glial changes to the widespread volume deficit of cortical gray matter seen in patients with schizophrenia with magnetic resonance images.


METHODS
Ten male veterans meeting criteria of the DSM-IV, for schizophrenia and 9 healthy age-matched men for comparison were scanned using spectroscopic, anatomical, and field-map sequences. Instrument and collection variables were standardized to allow an estimation of comparable values for NAA, choline, and creatine for all subjects. Metabolite values from each voxel on 3 upper cortical slices were regressed against the gray tissue proportion of that voxel to derive estimates of gray and white matter NAA, creatine, and choline concentrations.


RESULTS
The volume of cortical gray matter was reduced in patients with schizophrenia, but NAA signal intensity from a comparable region was normal. In contrast, the volume of cortical white matter was normal in patients with schizophrenia, but NAA signal intensity from a comparable region was reduced.


CONCLUSIONS
The lack of reduction in gray matter NAA signal intensity suggests that the cortical gray matter deficit in these patients involved both neuronal and glial compartments rather than a neurodegenerative process in which there is a decrease in the neuronal relative to the glial compartment. Reduced white matter NAA signal intensity without a white matter volume deficit may reflect abnormal axonal connections.
Lim
K O
KO
Psychiatry Service, Veterans Affairs Palo Alto Health Care System, Calif, USA. lim@nki.rfmh.org
Adalsteinsson
E
E
Spielman
D
D
Sullivan
E V
EV
Rosenbloom
M J
MJ
Pfefferbaum
A
A
D000328:Adult; D017668:Age of Onset; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D001921:Brain / Q000033:anatomy & histology* / Q000378:metabolism / Q000473:pathology; D001923:Brain Chemistry; D002794:Choline / Q000737:chemistry / Q000378:metabolism; D003401:Creatine / Q000737:chemistry / Q000378:metabolism; D004522:Educational Status; D006801:Humans; D007360:Intelligence; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline