To detect subtle changes in the neurometabolite concentrations by MRS, it is of utmost importance that the dominant contribution to the metabolic changes, is caused by the pathology of interest itself. Many studies involve surgery to interface e.g. cannulas to the brain. We investigate the impact of implanting an intracerebral cannula on the striatal neurochemical profile. MRS of the striatum from both hemisphere was performed 14d after surgery. A significant reduction of almost all metabolites was observed in the hemisphere with cannulation as well as contralateral side, indicating a dominant impact of the surgery, which might impact the sensitivity of MRS for quantification of pathologic processes.