Application Of CMRI And~1H-MRS In Differential Diagnosis And Assessment Of Cognitive Dysfunction In Multiple System Atrophy

ObjectiveAppling conventional magnetic resonance image (cMRI) technolo-gy to investigate brain structural changes of patients of multiple system atrophy (MSA). Appling1H-proton magnetic resonance spectroscopy (1H-MRS) to investigate the metabolic characteristics of frontal lobe, basal ganglia, cerebellum in MSA patients. To investigate the assessment value of cMRI associated with MRS in diagnosis of MSA subtypes and the severity of MSA patients. To investigate the metabolic changes of different brain regions in MSA patients with cognitive dysfunction.MethodsFirst, cMRI were operated on7cases of MSA with predominantly parkinsonian symptoms (MSA-P) and15cases of MSA with predomi-nantly cerebellar symptoms (MSA-C), and structural changes in different brain regions within the two groups were compared by diameterline measurement and signal detection. Then,1H-MRS were detected in7cases of MSA-P,15cases of MSA-C and48normal controls and the data of N-acetyl aspartate (NAA)/creatine (Cr), choline (Cho)/creatine (Cr), myoinositol (ml)/creatine (Cr) of the frontal lobes, basal ganglia, cerebe-llum was statistical analyzed. In the meantime, using the Unified Multiple System Atrophy Rating Scale (UMSARS) and Montreal Cognitive Asses- sment MoCA Beijing Version (MoCA) to assess scores in22MSA pati-ents. Carrying out correlation analysis between the scores and metabolic changes of different brain regions. At last, compare the brain metabolite changes of the frontal lobes between MSA patients whose MoCA scores were lower than25with48normal controls.Results1. Difference of basal ganglia MRI scan between MSA-P patients and MSA-C patients:the average lateral ventricular diameter of MSA-P group was longer than that of MSA-C group (P<0.05) and the lenticular nucleus in MSA-P group was obviously decreased in size (P<0.05), while the diameter of the third ventricle, the fourth ventricle,the cerebellar hemisphere and the anteroposterior diameter of the pontine had no statistical difference. There was no statistical difference between the two groups in high signal of pontine base and high signal of posterolateraln putamen.2. Difference of1H-MRS among MSA-P, MSA-C and control groups: the NAA/Cr ratio of bilateral frontal lobe and cerebellar hemisphere in MSA-P patients was significantly lower than that of normal control group (P<0.05), and the Cho/Cr ratio of the right side basal ganglia and cerebellar hemisphere was significantly higher (P<0.01).The NAA/Cr ratio of cerebellar hemisphere in MSA-C patients was significantly lower than that of MSA-P patients and normal control group(P<0.05). The Cho/Cr ratio of the right side basal ganglia in MSA-P patients was significantly higher (P<0.05), and the ml/Cr ratio of the cerebellar hemis-phere and the right side basal ganglia in MSA-P patients was significantly higher (P<0.01).3. Correlation analysis of proton magnetic resonance spectroscopy with the course, UMSARS score and MoCA score of the MSA-C patients and the MSA-P patients of different cereberal regions:The ml/Cr ratio of right basal ganglia district was positively correlated with UMSA-RS I score(r=0.786) and negatively correlated with the MoCA score(r=-0.837) in MSA-P patients. The ml/Cr ratio of left basal ganglia district was positively correlated with UMSARS I score(r=0.962) and UMSA-RSII score(r=0.788) and negatively correlated with the MoCA score(r=-0.835); The NAA/Cr ratio of cerebellum was negatively correlated with the course of the disease(r=-0.792) and UMSARS I score(r=-0.912). The ml/Cr ratio of cerebellum was positively correlated with UMSARSII score(r=0.804) and negatively correlated with MoCA score(r=-0.837). The ml/Cr ratio of left frontal lobe was negatively correlated with MoCA score (r=-0.521)in MSA-C patients. The Cho/Cr ratio of right basal ganglia was positively correlated with age of onset(r=0.522) and UMSARS I score(r=0.581), as well as UMSARSII scores(r=0.627),but was negatively correlated with MoCA score(r=-0.659). The ml/Cr ratio of right basal ganglia was negatively correlated with MoCA score(r=-0.542). The Cho/Cr ratio of left basal ganglia was positively correlated with UMSARSII score(r=0.667),but was negatively correlated with MoCA score (r=-0.594). The ml/Cr ratio of left basal ganglia was negatively correlated with MoCA score(r=-0.551), and the NAA/Cr ratio of cerebellum area was negatively correlated with UMSARSII score(r=-0.671).4. The NAA/Cr ratio of frontal lobe in MSA patients with cognitive dysfunction was significantly lower than that of normal control group (P<0.05).Conclusions1. The combination of cMRI and1H-MRS can help diagnose and classify the MSA patients.2. The cerebellar NAA/Cr ratio and the Cho/Cr ratio and ml/Cr ratio of basal ganglia and cerebellar can well reflect the severity of the MSA patients.3. The decrease of NAA/Cr ratio in frontal lobe may be correlated with MSA patients with cognitive dysfunction.