Gray matter density alterations in idiopathic generalized epilepsy patients: a double inversion recovery Magnetic Resonance Imaging study.

BACKGROUND

To investigate gray matter abnormalities in idiopathic generalized epilepsy (IGE) patients using double inversion recovery (DIR) sequence combined with statistical parametric mapping (SPM).

METHODS

We included a total of 31 IGE patients and 31 healthy controls. All participants underwent 3.0T MRI scans of T1WI, T2WI, FLAIR and DIR sequences. In the IGE group, seizure frequency, severity and electroencephalograph performance were recorded in IGE group. Gray matter intensity was analyzed using statistical parametric mapping through individual and group post-processing procedure of DIR images. Spearman analysis and multiple regression analysis were applied for further analysis of clinical factors and regions exhibiting abnormal gray matter intensity.

RESULTS

The individual SPM analysis of DIR images revealed gray matter abnormalities in 15 out of 31 IGE patients, affecting regions including the temporal lobe, frontal lobe, limbic lobe, occipital lobe, brainstem, insular lobe, parietal lobe, thalamus and cerebellum. Intergroup DIR-SPM analysis comparing IGE patients to healthy controls showed a significant increase in gray matter density in the left temporal lobe ( x = -44, y = -56, z = 6, Z score = 4.58, PFWE = 0.041; x = -48, y = -40, z = -12, Z score = 4.54, PFWE = 0.047). Generalized spike wave discharges (GSWDs) were positively correlated with the number of voxels exhibiting significantly altered gray matter intensity in each individual with IGE (PFDR = 0.032). However, the multiple regression model did not identify any significant brain regions influencing the occurrences of GSWDs.

CONCLUSIONS

In the IGE group, various regions exhibited alterations in gray matter density according to either individual or group DIR-SPM analysis. The frequency of GSWDs were correlated with the abnormal voxel count across the entire brain cortex of each individual with IGE.