Purpose: Atypical childhood epilepsy with centro-temporal spikes (ECTS) have less favorable outcomes than typical ECTS, and thus should be accurately identified for adequate treatment. We aimed to investigate the glucose metabolic differences between typical and atypical ECTS using 18F-fluorodeoxyglucose positron emission tomography ([18F]FDG PET) imaging, and explore the differences in brain metabolic network disorders in terms of metabolic connectivity between the two types of ECTS.
Methods: Sixty-eight patients with typical ECTS, 44 patients with atypical ECTS and 25 controls who underwent [18F]FDG PET examination were retrospectively involved. Absolute asymmetry index (|AI|) was applied to evaluate the severity of metabolic abnormality, and its correlation with clinical variables was analyzed. Correlation analysis between variables was performed using Pearson or Spearman rank correlation method. Multivariate linear regression analysis was used to evaluate the effect of clinical epilepsy-related factors on |AI|. Glucose metabolic differences were investigated among typical ECTS, atypical ECTS, and controls by using statistical parametric mapping (SPM). Moreover, the metabolic networks of typical ECTS, atypical ECTS, and controls were also constructed and analyzed based on graph theoretical analysis to explore topological alterations.
Results: The |AI| was found significantly higher in atypical ECTS than in typical ECTS (P = 0.000). Forty (59%) children with typical ECTS were found with hypo- metabolism, while children with atypical ECTS had a significantly different metabolic pattern (P = 0.028) with 31 (70%) hypo-metabolism and 5 (11%) hyper-metabolism. Multivariate linear regression analysis showed that onset age was the only significant factor for |AI| (Beta = -0.232, P = 0.016). Atypical ECTS showed more hypo-metabolism regions than typical ECTS, mainly located in the frontal lobe and lenticular nucleus. In the network analysis, both ECTS groups showed suboptimal topological organization, characterized by decreased global efficiency and increased modularity (P < 0.05). Atypical ECTS displayed more pronounced network disruption.
Conclusion: Compared with typical ECTS, atypical ECTS showed more widespread and severe hypo-metabolism, and presented more obvious brain network disorder, depending on which the two groups can be well distinguished. Metabolic characteristics can provide important value for the classification of ECTS.
 

Image/Figure:

Click to view full size

Image/Figure Caption:

a Overview of preprocessing and statistical analysis steps. b Differences in metabolic patterns. |AI| differences between typical and atypical ECTS, mono-therapy and poly-therapy ECTS. Correlation analysis between the |AI| and clinical variables. The significant glucose metabolic differences among three groups. c Differences in metabolic connectivity. The visualized metabolic networks of the three groups. Global network properties in different groups.

Author