Abstract #2139

Glutamate, Glutamine, NAA, and GABA Levels in Hippocampus in Schizophrenia as Measured by 1H-MRS at 3T

Ana Stan¹, Perry Mihalakos², Deborah Douglas³, Stephanie Morris², Changho Choi³, Carol Tamminga²

¹Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, Pittsburgh, PA, United States; ²Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States; ³Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States

We report a result of a 3T 1H-MRS study in schizophrenia. The concentrations of glutamate (Glu), glutamine (Gln), and N-acetylaspatate (NAA) in hippocampus (voxel 50x15x15 mm) were measured using a triple refocusing sequence. GABA was measured with a difference editing method. MRS scans were conducted on 13 schizophrenia volunteers (10 on medication (SV-ON) and 3 off-medication (SV-OFF)) and 14 normal volunteers (NV). LCModel fitting was used for spectral analysis. [Glu]/[Cr] was observed to be similar between NV and SV-ON (p = 0.4). However, [Glu]/[Cr] in SV-OFF was significantly lower (~30%) than in both NV and SV-ON (p = 0.02 and 0.04, respectively). For Gln, the concentrations were about the same between the three groups (p > 0.2). Compared to NV, [NAA]/[Cr] was reduced (by 10%) in SV-ON (p = 0.006), but not in SV-OFF (p = 0.55). The GABA data showed difference between SV-OFF and SV-ON (p = 0.05).