ABSTRACT
Objective To explore the mechanism of self-awareness in the heavy smokers(HS)by using regional homogeneity(ReHo)combined with resting-state functional MRI(fMRI).Methods Thirty HS and 31 healthy non-smokers(NS)matched for age and sex underwent a 3.0 T resting-state fMRI.The data were post-processed by SPM 5 and then the ReHo values were calculated by REST software.The ReHo values between the two groups were compared by two-sample t-test.The brain map with significant difference of ReHo value was obtained.Results Compared with that in NS group,the regions with decreased ReHo value included the bilateral precuneus,superior frontal gyrus,medial prefrontal cortex,right angular gyrus,inferior frontal gyrus,inferior occipital gyrus,cerebellum,and left middle frontal gyrus in HS group.The regions of increased ReHo value included the bilateral insula,parahippocampal gyrus,white matter of parietal lobe,pons,left inferior parietal lobule,lingual gyrus,thalamus,inferior orbital gyrus,white matter of temporal-frontal lobe,and cerebellum.The difference was more obvious in the left hemisphere.Conclusions In HS,abnormal ReHo on a resting state which reflects network of smoking addiction.This method may be helpful in understanding the mechanism of self-awareness in HS.
ABSTRACT
Objective To investigate whether abnormalities can be detected in normal-appearing white matter(NAWM)and normal-appearing white matter(NAGM)in patients with clinically isolated syndrome(CIS)and comparing them to the abnormalities in relapsing-remitting multiple sclerosis(RRMS)by using diffusion tensor imaging(DTI)histogram.To detect the potential relationship between DTI indices of NAWM,NAGM and patient's clinical condition.Methods Nineteen patients with CIS,19 clinically diagnosed RRMS patients and 19 sex-and age-matched healthy volunteers were included in this study.Conventional MRI and DTI images were obtained using Siemens 1.5 T Magnetom sonata scanner.DTI histograms of NAWM and NAGM were obtained after post-processing.The mean value,peak height,peak location of the histogram were used for analysis.All data was statistically processed with SPSS for Windows.Results NAWM average MD was higher and FA was lower in RRMS[MD(0.83±0.04)×10-3mm2/s,FA 0.36±0.03]when compared to CIS[MD(0.79±0.02)×10-3mm2/s,FA 0.40±0.02]and control[MD(0.78±0.02)×10-3mm2/s,FA 0.41±0.01](P＜0.01).But no statistically significant difference was found between CIS and control.The peak height of NAWM average MD histogram was significantly lower in CIS than control(P＜0.05),while the peak location of average FA histogram shifted to the left(P＜0.01).Patients with CIS[(1.08±0.06)×10-3mm2/s]showed significantly higher NAGM average MD than control[(1.03±0.05)×10-3mm2/s](P＜0.05),but,lower than RRMS[(1.18±0.12)×10-3mm2/s](P＞0.01).There were no correlation between DTI indices and EDSS scores in patients with CIS.Moderate correlation between NAGM average MD(r=0.568,P＜0.05)and EDSS scores were found in patient with RRMS.Conclusion NAWM and NAGM abnormalities do occur in CIS which can be detected by DTI.The underlying pathological changes in NAWM and NAGM in CIS may be milder than RRMS as demonstrated by DTI histogram.