The Application Of MoCA Test And DTI In Mild Cognitive Impairment

Background and Objective:Mild cognitive impairment(MCI)is now recognized as an intermediate clinical cognitive impairment stage between the normal aging and dementia,which has a high risk to develop into dementia.Early diagnosis of MCI offers possibilities for potential treatment with the aim of delaying or preventing the onset of AD.Therefore,MCI has been considered as the best stage for early diagnosis and intervention of AD.Current neuropsychological assessment commonly depends on Mini-Mental State Examination(MMSE).However,it can not clearly distinguish the normal aging elderly from MCI and early-stage Alzheimer disease(AD)patients because of the low sensitivity and specificity.Recently MoCA has been applied to assess the cognitive function,and valued for higher sensitivity and specificity when compared with MMSE for the early diagnosis of MCI.Diffusion tensor imaging(DTI)is a noval and unique technique that is able to show the brain white matters and their orientation in vivo,and can be used for quantitative studies.Compared with MRI to evaluate the hippocampus volume, DIT has exhibited the significant advantage for early diagnosis of MCI and AD.The ROI-based analysis has been widely used in the DTI study both at home and abroad.However,it is prone to depend on the operator,easily affected by the partial volume effect,and has high variation for the results.Recently-developed whole brain DTI voxel analysis is based on the highly automatic computer technology.It does not need hypothesis of brain regions variation,can rule out the subjective error of operator,and thus represent a comprehensively objective assessment for the whole brain DTI variation.It can evaluate the changes of brain white matter in MCI patients more precisely.In the 19resent study,the scores of MMSE,MoCA along with other cognitive functional tests were compared between the normal elderly and amnestic MCI (aMCI)patients.Additionally,DTI of whole brain voxel analysis was applied to analyze the brain fractional anisotropy(FA)so as to find out the characteristic changes in MCI patients and seek evidence for the early diagnosis of aMCI.Material and Methods:Fourteen retired army officers in Beijing with normal cognitive function together with 13 aMCI patients were included.MoCA,MMSE, CDR and Activity of daily living(ADL)were administered.Other tests including the Words memory,Abstraction,Conceptual thinking,Alternating trail making, Photo memory etc.,were used to assess the cognitive function.Cephalic DTI was scanned by the GE-Hc-3.0 T MRI.All the data were used for the voxel analysis, and the difference of cephalic FA value was compared.Results:The total scores of MMSE in the control and aMCI groups were 28.69±1.03 and 27.50±1.65 respectively,and was considered to be statistically significant(P＜0.05).The total scores of MoCA in control and aMCI groups were 25.85±1.52 and 22.50±1.91.Statistically analysis showed signigicant difference (P＜0.01).The scores of Verbal fluency in the control and aMCI groups were 19.08±4.92 and 15.14±4.66,and had statistically significant difference(P＜0.05). In the control group,the scores of Words memory,Delayed words memory,Words recognization and Photo recall were 5.54±0.88,5.15±1.77,9.15±1.07 and 13.92±2.69,while in aMCI group they were 3.98±1.07,2.14±1.23,7.00±2.04 and 10.57±2.31 respectively.Significant difference was found(P＜0.05).The tests of Conceptual thinking,Alternating trail making,Visuoconstructional Skills(Clock) and Photo naming showed no significant difference(P＞0.05).With a cut-off score of 24,MoCA had a sensitivity and specificity of 78.57%and 76.92%to detect subjects with MCI;MMSE had a sensitivity and specificity of 78.57%and 61.54%if a cut-off value of 28 was used.Significant difference were all found in both of them(P＜0.05).However,the area under ROC curve is dramatically larger in MoCA than in MMSE(0.923 versus 0.728).The DTI of whole brain voxel analysis showed the FA value is lower in aMCI than in contral group,and significant difference was found(P＜0.001).Conclusions:Compared with MMSE,MoCA can review the decline of total or some of the cognitive function in MCI patients more sensitively.It can identify the normal aging from aMCI patients more precisely.The DTI of whole brain voxel analysis can detect abnormal brain white matter in the early stage of cognitive function decline in MCI patients,which highlights its sensitivity when compared with conventional imaging exam in early screening of MCI.MoCA test together with DTI scanning provide new insights for the early non-invasive diagnosis of MCI,and is worth considering for application in the general clinical practice.