Rationale:
Rolandic epileptiform discharges (EDs) with tangential dipole (T-dipole) configurations are associated with favorable prognosis. Whether the same is true for T-dipole EDs in other brain regions is less established and is the objective of this study.
Methods: Over 20 years, patients with EDs were identified as follows:
frontal (F=176), temporal (T=196), central (C=201), parietal (P=120), and occipital (O=205). T-dipoles were documented.
Clinical features of children with and without T-dipole were compared both regardless of brain region and separately for each brain region.
Results: The prevalence of T-dipoles was 232/898 (25.8%) overall, and within different regions: T = 104 (53.1%), O = 51 (24.9%), P = 23 (19.2%), C = 35 (17.4%) and F = 19 (10.8%). Most had epilepsy: [T-dipole: 193 (83.2%) and non-dipole: 532 (79.9%)]. Regardless of region, T-dipole was associated with less drug-resistant epilepsy (DRE) [11 (4.7%) vs 202 (30.3%) p< 0.001], developmental delay (DD) [57 (24.6%) vs 436 (51.0%), p< 0.001), school-performance difficulties (SPD) [101 (43.5%) vs 410 (61.6%), p< 0.001], autism [30 (12.9%) vs 127 (19.1%), p=0.037] and abnormal examination [28 (12.1%) vs 257 (38.6%), p< 0.001)]. Within different brain regions, on logistic regression, T-dipole was associated with lower odds of DRE (F, T, C, P, and O), DD (F, T, C, and P), SPD (F, T, and C), autism (F, and T), abnormal examination (F, T, C, and O), and abnormal neuroimaging (T, C, P, and O).
Conclusions: On routine EEG analysis, focal EDs with T-dipoles, regardless of brain region, are associated with a more favorable clinical course.
Funding: The author received no financial support for the research, authorship, or support of this abstract.