A Study Of Cerebral Blood Flow Changes Of SPECT And TCD In Mild Cognitive Impairment Patients

Objective Applying single photon emission computed tomography(SPECT)andtranscranial Doppler(TCD)to investigate the changes of regional cerebral blood flow(rCBF) and brain hemodynamic in patients with mild cognitive impairment(MCI), toanalyze the relationship between the clinical characteristics of patients and rCBF,hemodynamic changes, as well as the cognitive changes, explore the underlying causeof the MCI patients, and provide a better basis for the early diagnosis of MCI andreasonable precautions for the purpose of delaying or prevention of dementia.Methods30cases of MCI group (male16, female14) were recruited. The age of thisgroup ranged from56to76, with an average age of68.45±9.65years; the years ofschooling ranged from4to16, with an average of9.30±3.96years. And20cases ofcontrol group (male12, female8) were recruited. The age of this group ranged from52to78, with an average age of63.56±10.26years; the years of schooling ranged from5to17, with an average of10.13±2.20years. All subjects underwent a generalexamination, neuropsychological score including Mini Mental State Examination(MMSE), Clinical Dementia Rating Scale (CDR), Activities of Daily Living Scale(ADL), Hamilton Depression Scale, and improved Hanchinski table (Loeb ratings), thena brain SPECT perfusion imaging and TCD examination were performed.Results Compared with the control group, the rCBF in the bilateral frontal lobe, the leftparietal lobe and the bilateral interior temporal in the MCI group were significantlyreduced (P<0.05). Within the group of MCI, the rCBF in the left frontal, left superior parietal lobule, and left temporal lobe was significantly reduced compared with the rightcorresponding parts (P<0.01). The incidence of one or more abnormal TCDhemodynamics parameters including the peak flow velocity (Vp), mean flow velocity(Vm), the systolic-diastolic ratio of blood flow velocity (S/D), pulsatility index (PI),resistance index (RI) and frequency spectrum changes increased significantly in theMCI group (60%) compared with the control group (20%)(χ~2=5.92, P<0.05). Vp andVm in the middle cerebral artery (MCA) and anterior cerebral artery (ACA) reducedsignificantly and S/D, PI and RI increased significantly in the MCI group (P<0.05).Conclusion①In MCI patients there is a certain degree of brain perfusion reduced inthe part of the brain regions, which located in the frontal, parietal, and medial temporallobe, especially on the left side.②In MCI patients there is an abnormal TCD cerebralhemodynamics changes. In MCA and ACA of the anterior circulation systems, there is adecrease of cerebral blood flow velocity and an increase of PI and RI, with an abnormalfrequency spectrum.③SPECT and TCD have a certain value to detect the underlyingcause of MCI patients, and are useful to the prediction of the patients′conversion.