THE AGE EFFECT UPON FNIRS MEASURED BRAIN FUNCTION BETWEEN SCHIZOPHRENIA PATIENTS AND NORMAL CONTROLS

Abstract Background Schizophrenia has been considered as a brain disorder which deteriorates cognitive and social function in affected people. Whether the aging effect will further decline the brain function of schizophrenic patients or not is rarely discussed before. Aims & Objectives We here applied fNIRS (functional infrared spectrometry) to measure brain function of schizophrenia to tell the difference from normal with age effect adjustment. Method We recruited schizophrenia people and normal controls with different age from 2015 to 2018 with IRB approval in one medical center in central Taiwan. After consent form completed, their brain function performance was measured by using Hitachi ETG 4000 with both centroid and integral data over frontal and bilateral temporal regions channels once. The standard VFT (verbal fluency test) Taiwan version was tested to record the change of oxygenated and deoxygenated hemoglobin reflection curve during the task. Results The sample size is 87 for schizophrenic patients and 88 for normal controls. The average integral value of frontal function is lower in people with schizophrenia compared to normal controls, and between group difference is decreasing while people getting older (Fig 1). The average centroid value of frontal function is higher in people with schizophrenia over normal one at any age stage, and the average group gap is increasing by years of aging (Fig 2). Discussion & Conclusion The brain function by measuring integral value showed the total working performance during VFT, which showed a greater slope of decline in normal people compared to schizophrenia. However, the reaction lag time after task start during VFT by observing centroid value is prolonged among old people with schizophrenia compared to normal control ones, it might reveal a worse response on cognitive performance for older schizophrenic patients at the same age level. In general, the brain function measured by fNIRS showed a worse outcome in people with schizophrenia compared to normal controls with compatible age level.