Prevalence Of Apathy In White Matter Lesions And The Association With Cognitive Impairment

Aims: To investigate the prevalence of apathy in patients with white matter leisions and the association with cognitive impairment,moreover,to analyze the possible relationship among those two and the plasma level of total homocysteine(t Hcy)and specific inflammatory cytokines(IL-6、CRP、TNF-α).Methods:1.Fourty-four patients with magnetic resonance imaging(MRI)confirmed white matter lesions and the same number of healthy controls were recruited from the Affiliated Hoszpital of Southwest Medical University.There was no obvious differences in general charactors between the two groups.2.The Modified Apathy Evaluation Scale(MAES)was used in all participates to identify wether there was an apathy(score>14 is defined as positive result).The incidence of apathy in WMLs and control group was caculated respectively,and the patients with WMLs was devided into two groups:apathy and no apathy.3.Fasting venous blood was collected to assess the difference of the t Hcy and specific inflammatory cytokines(IL-6、CRP、T N F-α)lev els in WMLs/co ntro l group and WMLs with/wit hout apathy.4.Mini-mental State Examination and Montreal Cognitive Assessment were used to evaluate the general cognitive function,furthermore,Trail Making Test(TMT)and Stroop Color-Word Test were used to analyse the executive function of participants with WMLs with and without Apathy.Finally,sorted out and analysed all the data collected.Results:1.The patients with WMLs had a higher prevalence of apathy,with significant differences compared to the control group [36.4% VS 15.7%].And the incidence of apathy in moderate/sever WMLs patients was significantly higher than mild WMLs patients [54.5% VS 18.2%].2.The plasma level of t Hcy(11.82±3.17μmol/L),IL-6(99.92±18.43ng/ml)and TNF-α(233.99±84.35ng/ml)in WMLs patients w e r e o b v i o u s h i g h e r t h a n c o n t r o l g r o u p w h i c h w e r e 8.46±1.52μmol/L,37.87±6.40ng/ml and 34.51±6.33ng/ml,respectively(P<0.05 for each).Moreover,the level of t Hcy and IL-6 in sever WMLs patients were significantly higher than mild patients.3.In WMLs patients,people with apathy had a higher level of IL-6(106.34±11.68ng/ml),CRP(5.13±4.29mg/ml)and t Hcy(13.77±3.18μmol/ml)compaired with those without the disorder.Multiple linear regression analysis showed that IL-6(standardized partial regression coefficient b ’=0.542,P=0.000)and CRP(standardized partial regression coefficient b’ =0.349,P=0.002)can significantly affect the MAES score,the higher the level of IL-6 and CRP,the more sever of apathy.4.A significantly lower score of WMLs patients with apathy gained MMSE(18.00±7.16)and Mo CA(13.00±5.89)than those without apathy.Pearson correlation test showed that MMSE and Mo CA scores were negatively correlated with MAES score.5.The reaction time(RT)of Stroop Color-Word Test C,Stroop interference effects(SIE),the completion time for TMT-A/B and the interference index in WMLs patients with apathy were all higher than the cases without apathy(P<0.05).Pearson correlation test showed that the SIE and the interference index of TMT were negatively correlated with MAES score.Conclusions:1.Apathy is a common symptom in patients with white matter leisions,and the more sever the lesions are got,the higher the prevalence of apathy is.2.The plasma levels of t Hcy,IL-6 and TNF-αare closely related to the emergence of white matter lesions,moreover,the levels of t Hcy and IL-6 are correlated with the severity of white matter lesions.3.In WMLs patients,the plasma levels of IL-6,CRP and t Hcy are related to the emergence of apathy,and the higher the levels of IL-6 and CRP are,the more serious the apathy is.4.In WMLs patients,cases with apathy suffer a more sever cognitive and executive function impairnment compared with no apathy cases.