DTI Assessment Of Brain White Matter Structural Changes In Nicotine Dependent Population

Background and purposeTobacco is one of the public health problem for the greatest impact of human in the world today.Smoking is the most important risk factor for chronic diseases of people.Smoking is next to hypertension as the second most factor in the global disease risk factors.Previous studies have shown that smoking can lead to multiple organs including respiratory system,nervous system and other organs and can also cause malignant diseases such as lung cancer and nasopharyngeal carcinoma.Although most nicotine dependence population have a strong desire to quit smoking,most individuals who quit smoking are relapsing within a short time generally.Previous studies of smoking focus on brain function,and the impact on brain structure is controversial.Diffusion tensor imaging(DTI)is currently the only noninvasive method that can detect brain microstructure in vivo from cellular and molecular level.It can display the microstructure,morphology and density of white matter fibers without trauma.The purpose is to study the changes of white matter microstructure use tract-based spatial statisticas(TBSS)of DTI technique in nicotine dependence population,and to analyze the FA correlation with smoking index,smoking age and daily smoking quantity.Materials and methodsIn this study,124 nicotine dependent population and 52 non-nicotine dependent healthy volunteers were scanned with Siemens Skyro 3.0T magnetic resonance scanner.The nicotine dependence population were divided into mild nicotine dependence group(FTND<6)and severe nicotine dependence group(FTND?6),subjects to check the matters needing attention.Conventional MRI(to exclude intracranial lesions)sequence and DTI sequence were performed in all subjects.DTI data were processed by TBSS preprocessing method.Age and education level were used as covariates.The SPSS 17.0 software was used to make Spearman correlation analysis between different nicotine dependence group and control group and smoking data.ResultsCompared with the control group,mild nicotine dependence group in genu and body of corpus callosum,left anterior corona radiata,right superior corona radiata,right posterior corona radiata,bilateral posterior thalamic radiation(include optic radiation),the left superior longitudinal fasciculus multiple brain regions significantly decreased FA value,these brain regions FA negative related with smoking index,smoking age,smoking amount.Compared with the control group,the severe nicotine dependence group except the right cingulate cortex,the cerebral white matter fiber bundle FA decreased,which genu of corpus callosum,bilateral anterior corona radiata,bilateral superior longitudinal fasciculus,bilateral posterior thalamic radiation(include optic radiation),posterior limb of internal capsule FA value negative related with the smoking index,smoking age,smoking amount.With mild nicotine dependence group contrast,the severe nicotine dependence group in genu of corpus callosum,bilateral anterior limb of internal capsule,left retrolenticular part of internal capsule,bilateral anterior corona radiata,left posterior thalamic radiation(include optic radiation),bilateral external capsule,left superior longitudinal fasciculus,right uncinate fasciculus multiple brain regions decreased FA.These brain regions FA negative related with smoking index,smoking age,smoking amount.ConclusionsSmoking has a certain effect on the white matter structure for different degree of nicotine dependent patients.The severe nicotine dependence group white matter structure damage is more serious,and these changes of white matter structure affect the function of corresponding brain regions.There was a negative correlation between the FA value of white matter structure and smoking index,smoking age and smoking amount in different regions of nicotine dependence,indicating that nicotine had a cumulative effect on the structure of white matter.