Near-infrared Spectroscopy Imaging Study On Brain Activation Characteristics Of The Verbal Fluency Task In Patients With Vascular Dementia

Objective: This study intends to analyze the features of lower prefrontal lobe and temporal lobe activation of patients with vascular dementia,during the performing of verbal fluency task(VFT).To do so,general information and medical history of patients with vascular dementia were collected,as well as sleep scale,cognitive function scale,and near-infrared spectroscopy data wereanalyzed.Methods: Thirteen patients from the First Affiliated Hospital of Hebei Medical University,Shijiazhuang City Eighth Hospital,Shijiazhuang Gao cheng District People’s Hospital and Luquan District People’s Hospital were selectedas subjects.All of the patients met the ICD-10 diagnostic criteria for vascular dementia,with a clear history of stroke or no history of stroke but clear imaging(cranial MRI or CT)evidence.A near-infrared spectroscopy imaging technology(f NIRS)evaluation using 52 channels was conducted to the patients along with a control group(includes 14 subjects selected from various communities in Shijiazhuang),to reveal the changes of blood flow in prefrontal and bilateral temporal lobes during VTF.The differences of the peak time of oxy-Hb,deoxy-Hb and total hemoglobin(total-Hb)concentrations were compared two groups of subjects when the task was completed.Results: In the verbal fluency task,compared with the normal control group,the average peak time of oxy-Hb,deoxy-Hb and total-Hb concentration of 52 channels in the vascular dementia group was delayed(P>0.05),but there is no significant difference in delaying time.Subject group’s various channels of integral value in left central anterior gyrus,left and right central posterior gyrus,left and right frontal poles,left middle frontal gyrus,bilateral inferior frontal gyrus,left orbital frontal lobe,and right superior temporal gyrus were much higher than that of thecontrol group’s(P<0.05),yet ?Hb O in right frontal pole,left and right middle frontal gyrus,left orbitofrontal lobe,right posterior central gyrus were lower(P<0.05).The results indicates that the stimulation intensity required for activation of oxy-Hb,deoxy-Hb and total-Hb was significantly higher than hat of the normal control group.Conclusion: In patients with vascular dementia,there may be delays in the activation of the prefrontal and temporal cortex when performing speech fluency tasks,and the required stimulation intensity increases dorrespondingly.