Effect of education level on cognitive function in patients with Parkinson′s disease / 中华神经科杂志

ABSTRACT

Objective To investigate the relationship between educational level and cognitive function in patients with non?dementia Parkinson′s disease (PD). Methods Forty non?dementia PD patients and forty healthy controls (HC) enrolled in Beijing Hospital from January to December 2018 were collected for the study. The two groups were divided into three subgroups (low, medium and high) according to their years of education. HC group and PD group were matched in age, gender, years of education, and Mini?Mental State Examination score. All subjects underwent three tests of executive function: the Trail Making Test (TMT?A and TMT?B), the Verbal Fluency Test (VFT) and the WAIS digital span test (forward and backward). Results There were statistically significant differences in the error number of TMT?A (0.00 (0.00, 1.00),0.00 (0.00, 0.00), 0.00 (0.00, 0.00); χ2=10.11, P=0.006), the time of TMT?B ((81.17±36.83) s, (52.10 ± 27.88) s, (47.72 ± 23.18) s; F=5.16, P=0.011), the error number of TMT?B (3.00 (0.00, 4.00), 1.00 (0.00, 3.50), 0.00 (0.00, 0.00); χ2=7.16, P=0.028) and the number of backward (3.17±0.72, 3.50±1.08, 4.00± 0.77; F=3.68, P=0.035) among the three subgroups of PD group. There were statistically significant differences between the PD group and the HC group in the time of TMT?A (PD: (64.03±15.96) s, HC: (53.00± 19.50) s; t=2.77, P=0.007), the time (PD: (58.85±31.91) s, HC: (37.35±19.42) s; t=3.64, P=0.001) and error number (PD: 0 (0, 4), HC: 0 (0, 0); Z=-3.15, P=0.002) of TMT?B, the number of backward (PD: 3.63±0.90, HC: 4.98±1.21; t=-5.67, P=0.000) and VFT (PD: 14.48±3.37, HC: 16.15±2.03; t=-2.69, P=0.009). In the low and medium education level subgroups, the PD group showed worse results in three tests of executive function than the HC group, some with statistically significant differences (P<0.05). There was no statistically significant difference in the results of three tests of executive function between two subgroups of high education in the PD group and the HC group (P>0.05). Conclusions Executive functions of non?dementia PD patients are impaired. Education level may have a certain impact on cognitive function of PD patients.