OBJECTIVE: Abnormalities in frontal lobe phosphorous metabolism in
patients with bipolar disorder have been reported, but many of the patients
studied were receiving lithium. In this study, medication-free bipolar
patients were examined to determine abnormalities in frontal lobe
high-energy phosphorous metabolism. METHOD: In vivo phosphorous-31 magnetic
resonance spectroscopic imaging was performed on 12 unmedicated, euthymic
bipolar patients and 16 healthy comparison subjects. The percentages of
total phosphorous signal for phosphomonoesters, inorganic phosphate,
phosphodiesters, phosphocreatine, and beta-ATP were calculated. RESULTS: In
relation to the comparison group, the patients with bipolar disorder had
significantly lower phosphomonoester values and higher phosphodiester
values in both the left and right frontal lobes. The patients also had a
significantly higher right-to-left ratio of frontal lobe phosphocreatine.
No other differences in phosphorous metabolites or lateralized asymmetries
were noted. CONCLUSIONS: This preliminary study provides support for
abnormal frontal lobe phosphorous metabolism in bipolar disorder.