Objective To study the association between serum homocysteine (Hcy) level and cognitive impairment in PD patients.Methods Eighty-one PD patients admitted to our hospital were divided into normal cognition group (n=25),mild cognitive impairment group (n=32) and dementia group (n=24) with 19 healthy persons undergoing physical examination served as a control group.Their cognitive impairment was assessed according to their medical history,detailed physical examination data,Hoehn-Yahr scale score,MMSE score,and CDR score.Their serum levels of Hcy,folic acid and vitamin B12 were measured.The association of serum Hcy,folic acid and vitamin B12 levels with cognitive impairment was analyzed.Results The serum Hcy level was significantly higher in normal cognition group,mild cognitive impairment group and dementia group than in control group (P＜0.05,P＜0.01) and in dementia group than in normal cognition group (14.8±3.9 μmol/L vs 12.5±3.3 μmol/L,P＜0.05).The serum Hcy level was associated with oral levodopa and oral benserazide daily dose,oral levodopa and oral benserazide taking time,course of PD and age (r=0.298,P=0.000;r=0.280,P=0.000;r=0.301,P=0.000;r=0.184,P=0.019) but not associated with the severity of PD.Conclusion High serum Hcy level is one of the risk factors for cognitive impairment in PD patients,and control of oral levodopa dose contributes to the prevention and treatment of dementia in PD patients.

Objective To analyze the association ofdopamine receptor D2 (DRD2) TaqIA gene polymorphism with persistent postural-perceptual dizziness (PPPD) and explore the molecular mechanism of this disease.Methods The study group consisted of 43 patients diagnosed as having PPPD was chosen in our hospital from January 2017 to June 2017;45 gender-and age-matched control subjects were selected randomly from acute vertigo patients who were fully recovered within 3 months without selective serotonin reuptake inhibitors (SSRIs) or serotonin norepinephrine reuptake inhibitors (SNRIs) medication and were normal at 6 months of follow up.Personality characteristics of the two groups were analyzed by adult Essen personality inventory.Frequencies of DRD2 TaqIA gene polymorphism were detected with polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).Results Percentage of neurotic individuals in study group (67.4％) was significant higher than that of control subjects (37.8％,P＜0.05).Genotype distribution ofA1/A1,A1/A2,and A2/A2 showed significant difference between the two groups (P＜0.05).In the study group,A1 and A2 allele frequencies in the DRD2 TaqIA gene were 65.1％ and 34.9％ respectively,which had significantly difference as compared with those of control subjects (46.7％ and 53.3％,P＜0.05).Conclusion A 1 allele in DRD2 TaqIA gene may be the susceptibility gene for PPPD.

Objective:To analyze the relation between DNA methylation in the CpG island of dopamine D2 receptor ( DRD2) gene promoter region and persistent postural-perceptual dizziness (PPPD), and explore the molecular mechanism of PPPD. Methods:The disease group consisted of 43 patients diagnosed as having PPPD in our hospital from January 2017 to June 2017, and blood samples were taken at admission. The control group included 45 with acute vestibular peripheral vertigo whose dizziness symptoms did not recrudesce after follow-up for more than 3 months and PPPD diagnosis was excluded in our hospital at the same period; these patients did not take selective serotonin reuptake inhibitors (SSRIs) or serotonin norepinephrine reuptake inhibitors (SNRIs); blood samples in the patients were collected during follow-up. DNA methylation in the CpG island of DRD2 promoter region was detected by disulfite sequencing and the differences between the two groups were compared. Results:The positive rate of DNA methylation in the CpG island of DRD2 promoter region in the disease group was 58.1%, which was significantly higher than that in the control group (15.6%, P<0.05); and the methylation rate of CpG island loci in the disease group (0.15±0.18) was significantly higher than that in the control group (0.04±0.10, P<0.05). Conclusion:The DNA methylation in the CpG island of DRD2 promoter region is associated with onset of PPPD.