Regional Cerebellar Gray Matter Volume Changes In Epilepsy

Background:Epilepsy is a chronic neurological disease,which is caused by abnormal neuronal excitability and dynchronization of discharge and leads to transient cereberal function disorder.Chronic epilepsy leads to inreversible neurologic deficits,resulting in severe cognitive and behavioral impairment.Cerebellum,who plays an important role in motor function,is the control center for maintaining body balance,regulating muscle tone and coordinating movement.Recently,numberous studies demonstrated that cerebellum is also involved in cognitive process,including learning,memory,language,attention and emotion functions.However,the role of cerebellum in epilepsy are still controversial.Previous pathology and imaging study reported the atrophy of cerebellum in epilepsy,with the change of blood perfusion,metabolism and connectivity,indicating that the cerebellar structure and function may be impaired by the paradoxical discharge caused by seizure or cerebellum may involved in the neural networks of epilepsy.Based on the magnetic resonance imaging(MRI),we revealed,in normalized cerebellar space,the difference of total and regional cerebellar gray matter volume(GMV)between epilepsy and control and the relationship with epilepsy type,clinical factors,surgery outcome and cognition.Part Ⅰ:Regional cerebellar gray matter changes in refractory temporal lobe epilepsy and the relationship with surgery outcomeAim:Based on the 3T MRI data,we revealed,in normalized cerebellar space,the cerebellar subregional volume change in refractory temporal lobe epilepsy(TLE)and its relationship with postsurgery outcome.Materials and Methods:we collected the 3D T1 MRI data of 32 patients who were radiologically,EEG and pathology defined as refractory TLE and 16 healthy controls matched for age,gender,handness and education level.All the TLE patients underwent a standard postoperation follow-up and outcome was assessed by using the International League Against Epilepsy(ILAE)outcome classification system.Spatially unbiased infra tentorial template(SUIT)were used to analyze the regional cerebellar GMV changes in TLE,the association with clinical factors and the difference of GMVin patients with different surgery outcome.Results:Total cerebellar GMV were associated with age,seizure frequency and duration,and the former two were independent variable of cerebellar GMV in TLE patients.The TLE patients showed GMV atrophy in a large range of cerebellar lobules including bilateral Ⅰ-Ⅳ,right Ⅴ,bilateral Ⅵ,bilateral crus Ⅰ,bilateral crus Ⅱ,bilateralⅦb,left Ⅷa,bilateral Ⅸ,VermisⅥ,Ⅷa/b,Ⅹ when compared to control.Durationwas significantly correlated with the GMV of ROI in right crus Ⅰ and Ⅱ while seizure frequency was negatively correlated with the GMV of ROI in bilateral Ⅰ-Ⅳ and right crus Ⅰ.Age was negatively correlated with the GMV of ROI in right crus Ⅰ and crusⅡ.No significant difference of cerebellar GMV were found between patients with excellent(ILAE 1)and suboptimal(ILAE 2-6)postoperative outcomes.Conclusion:The widespreaded regional atrophy of cerebellar GMV were found in refractory TLE,and was correlated with duration and seizure frequency,but not with surgery prognosis.Part Ⅱ:Regional cerebellar gray matter changes in extratemporal lobe epilepsyAim:Based on the 3T MRI data,we revealed,in normalized cerebellar space,the cerebellar subregional volume change extratemporal lobe epilepsy(ELE),the difference between TLE cerebellar GMV changes,and its relationship with postsurgery outcome.Materials and Methods:We collected the 3D T1 MRI data of 16 patients who were radiologically,EEG and pathology defined as extratemporal lobe epilepsy(including 9 frontal lobe epilepsy,3 parietal lobe,2 occipital lobe and 2 insula lobe)and 16 healthy controls matched for age,gender,handness and education level.All the ELE patients underwent a standard postoperation follow-up and outcome was assessed by using ILAE outcome classification system.SUIT were used to analyze the regional cerebellar GMV changes in ELE when compared to CTR and TLE,the association with clinical factors and the difference of GMV in patients with different surgery outcome.Results:a.Total cerebellar GMV was associated with age and duration,which were independent variables of cerebellar GMV in ELE patients.b.The ELE patients showed GMV atrophy in a large range of cerebellar lobules including bilateral Ⅰ-Ⅳ,bilateral Ⅴ,bilateral Ⅵ,bilateral crus Ⅰ,bilateral crus Ⅱ,right Ⅶb,bilateral Ⅷa/Ⅷb,bilateral IX,Vermis Ⅷa when compared to control.c.ELE had more frequent seizure when compared to TLE.d.When compared to TLE,the GMV of right Ⅶb/Ⅷa,rightⅧb/Ⅸ and left Ⅷa,left Ⅷb were smaller in ELE.The age was negatively correlated with the GMV of ROI in right Ⅷa.e.No significant difference of cerebellar GMV were found between patients with excellent(ILAE 1)and suboptimal(ILAE 2-6)postoperative outcomes.Conclusion:The ELE patients showed a widespreaded and bilateral cerebellar subregional GMV atrophy,which was similar with the cerebellar subregional GMV atrophy found in TLE expect the Ⅷ.ELE showed smaller bilateralⅧGMV than TLE patients,and the ROI were correlated with age.Cerebellar atrophy did not affect the surgery prognosis in ELE patients.Part Ⅲ:Regional cerebellar gray matter volume changes in chronic epilepsy and the association with cognitionAim:Based on the 3T MRI data,we aimed to figure out whether the cerebellar subregional volume changes in chronic epilepsy were related with cognition.Materials and Methods:We collected the 3D T1 MRI data of 16 chronic epilepsy patients and 16 healthy controls matched for age,gender,handness and education level.A comprehensive neuropsychological battery was used for evaluation covering global cognitive function,memory function,executive function,visual spatial skills,language function.Correlation analysis between the GMV of changed clusters(ROIs)in chronic epilepsy and cognition scales were carried out in SPSS.Results:a.The chronic epilepsy patients showed GMV atrophy in a large range of cerebellar lobules including left Ⅰ-Ⅳ,bilateral Ⅴ,bilateral Ⅵ,bilateral crus Ⅰ,left crus Ⅱ,left Ⅶb,bilateral IX,Vermis Ⅷa and Ⅷb when compared to control,b.For the global cognitive function,MMSE score was positively correlated with the GMV of ROI in left crus Ⅱ.Language function test showed that AVLT2 was positively correlated with the GMV of ROl in left crus I while AVLT3 was positively correlated with the GMV of ROI in vermis Ⅷb.AVLT35 was positively correlated with the GMV of ROI in left crus Ⅰ.AVLT31 was positively correlated with the GMV of ROI in vermis Ⅷb.For the excutive function,TMT A and TMT B was negatively correlted with the GMV of ROI in left IX.In Stroop test,CWTc was negatively correlated with the GMV of ROI in left Ⅶb.SDMT was positively correlated with the GMV of ROI in vermis.For the spartial function,CDT score was positively correlated with the GMV of ROI in left crus Ⅱ.For the language function,BNT score was nearly negatively correlated with the GMV of ROI in right crus I.VFTanimal and VFTvegetabie were both positively correlated with the GMV of ROI in vermis Ⅷb and left IX.Conclusion:Cognitive function might be related with subregional cerebellar gray matter atrophy in the posterior lobe(especially Ⅶ)and posterior vermis in chronic epilepsy.