Background: Studies in schizophrenia using in vivo (31)P magnetic resonance spectroscopy (MRS) have mostly focused on the association cortices, including the frontal and temporal lobes. Striatum has also been implicated in schizophrenia, although neuroleptic exposure in the patients is a potential confound limiting interpretation of earlier studies. We examined membrane phospholipid abnormality in the basal ganglia using (31)P MRS in neuroleptic-naive schizophrenia patients.
Methods: Never-treated, DSM-IV schizophrenia patients (n=20) and age- and gender-matched healthy control subjects (n=30) underwent in vivo 1-D 31P MRS of both basal ganglia using an image-selected technique on a 1.5-T magnetic resonance imaging scanner. A neuroradiologist blind to clinical data measured the phosphomonoester (PME) and phosphodiester (PDE) from the spectra.
Results: The schizophrenia patients showed significantly and bilaterally elevated levels of PME/PDE ratios in basal ganglia as compared with control subjects. There were no significant differences in the ratios between the two sides in either patient or control groups. Phosphomonoester/phosphodiester ratio did not correlate with illness duration. Lower Positive and Negative Syndrome Scale scores were associated with lower PME/PDE ratio.
Conclusions: The basal ganglia of never-treated schizophrenia patients show features suggestive of reduced breakdown and/or increased synthesis of membrane phospholipids. Lack of correlation between illness duration and the membrane phosphorus moiety ratio may be consistent with a nonprogressive, possibly neurodevelopmental etiopathogenesis.