Parietal white matter abnormalities in obsessive-compulsive disorder: a magnetic resonance spectroscopy study at 3-Tesla.
OBJECTIVE
To identify a neurochemical basis for the hypothesis that an aberrant cortico-subcortical circuit underlies obsessive-compulsive disorder (OCD). The white matter was also investigated because of recent research which suggests the altered connectivity of axons.


METHODS
Using 3-Tesla magnetic resonance spectroscopy, the relative concentrations of N-acetylaspartate (NAA) and choline-containing compounds (Cho) to creatine/phosphocreatine (Cr) were measured in the anterior cingulate, basal ganglia, thalamus, frontal and parietal white matter of 12 OCD patients, and 32 control subjects.


RESULTS
The mean concentration of Cho/Cr was significantly higher in the patients than in the controls, but only in the parietal white matter, while no significant group differences in NAA/Cr were observed in any of the brain regions. Parietal Cho/Cr correlated positively with the severity of OCD symptoms.


CONCLUSIONS
This finding provides indirect evidence for the parietal white matter involvement in OCD, thus suggesting a change in the phospholipids of myelinated axons and/or glia cells.
Kitamura
H
H
Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. kitamura@med.niigata-u.ac.jp
Shioiri
T
T
Kimura
T
T
Ohkubo
M
M
Nakada
T
T
Someya
T
T
D000293:Adolescent; D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009415:Nerve Net / Q000378:metabolism / Q000503:physiopathology; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D010296:Parietal Lobe / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000503:physiopathology; D011859:Radiography
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline