MRS at 3 Tesla in Brain of Schizophrenic Patients: Elevated Glutamate in Hippocampus Decreases on Therapy

Florian Schubert¹, Frank Seifert¹, Karolina Leopold², Michael Krebs², Ines Haeke², Juergen Gallinat², Martin Schaefer²

We performed proton MRS in hippocampus (HC) and cingulate of 30 controls and 30 schizophrenics (on neuroleptics), 17 diagnosed as acute and 13 as chronic. Glutamate was quantified with a dedicated method at TE=80ms to test the influence of memantine, an NMDA receptor antagonist, on cortical glutamate. After baseline examination patients received additional therapy with either memantine or placebo in a double blind study design. Follow-up MRS was performed after 6 weeks. Apart from elevated Glu in patients' HC at baseline, HC-Glu significantly dropped in the group of acute schizophrenics during combination therapy, whereas in the chronic group it remained unchanged.