Correlation between Patterns of Focal Epileptiform Discharges and Brain Lesions in Children with Focal Epilepsy

Kim, Tae Hyoung; Lee, Yun Jin; Kim, Young Mi; Nam, Sang Ook

Abstract

PURPOSE
The objective of this study was to evaluate the correlation between patterns of focal epileptiform discharge (ED) and brain lesions diagnosed by MRI in children with focal epilepsy.
METHODS
We retrospectively reviewed routine scalp EEGs, medical records, and results from brain MRIs in 149 children who had been diagnosed as epilepsy with focal epileptiform discharges in our hospital between 2008 and 2010. We classified the patterns of focal ED into spikes, sharp waves, and polyspikes. EEGs with homogenous patterns of ED were termed single-form ED and those with heterogenous patterns of ED were termed multi-form ED. We evaluated the relationship between the specific patterns of focal ED and brain lesions in pediatric epilepsy.
RESULTS
Fifty-six of 149 (37.6%) patients had brain lesions on brain MRI. 67.8% (101/149) patients exhibited single-form ED and 32.2% (48/149) patients revealed multi-form ED. Thirty of 48 patients (62.5%) with multi-form ED showed brain lesions, which was higher than those for patients with single-form ED (25.7%, 26/101) (P <0.001). 27.5% (41/149) patients had and 25/41 (61.0%) also had brain lesion, which was higher than those for patients without polyspikes (28.7%, 31/108) (P <0.001). 19 of 82 patients (23.2%) with single-form ED with spikes only had brain lesion on brain MRI, which was significantly lower than those of remaining patients (55.2%, 37/67) (P <0.001).
CONCLUSION
We suggest that a heterogenous pattern of ED or polyspikes lead to a higher incidence of brain lesions in children with focal epilepsy.