Table 1.
Independent firing and interaction of the frontal-parietal neocortical and hippocampal epileptic foci as observed by paired epidural and depth-electrode recordings 6.5−7 months post-FPI.
| Type of occurrence | Proportion | Evidence for focus in: | ||
|---|---|---|---|---|
 |
Grade 1 seizures in absence of hippocampal discharge: | 66.7% | Frontal-parietal cortex | |
| Grade 1 seizures leading hippocampal discharge: | 13.9% | Frontal-parietal cortex | ||
| Grade 1 seizures simultaneous to hippocampal discharge: | 19.4% | Undefined | ||
| Grade 1 seizures led by hippocampal discharge: | 0.0% | Not hippocampus | ||
 |
Grade 2 seizures in absence of hippocampal discharge: | 2.2% | Frontal-parietal cortex | |
| Grade 2 seizures leading hippocampal discharge: | 80.4% | Frontal-parietal cortex | ||
| Grade 2 seizures simultaneous to hippocampal discharge: | 17.4% | Undefined | ||
| Grade 2 seizures led by hippocampal discharge: | 0.0% | Not hippocampus | ||
 |
Grade 3 seizures in absence of hippocampal discharge: | 0.0% | Not frontal-parietal cortex | |
| Grade 3 seizures leading hippocampal discharge: | 0.0% | Not frontal-parietal cortex | ||
| Grade 3 seizures simultaneous to hippocampal discharge: | 56.3% | Undefined | ||
| Grade 3 seizures led by hippocampal discharge: | 43.7% | Hippocampus | ||
 |
Anterior hippocampus in absence of posterior hippocampus: | 71% | Anterior hippocampus | |
| Anterior hippocampus leading posterior hippocampus: | 7.9% | Anterior hippocampus | ||
| Anterior hippocampus simultaneous to posterior hippocampus: | 21.1% | Undefined | ||
| Anterior hippocampus led by posterior hippocampus: | 0.0% | Not posterior hippocampus | ||
| w/ s.e. | w/o s.e. | |||
 |
Frontal-parietal seizures in absence of hippocampal discharge: | 14.6% | 24.4% | Frontal-parietal cortex |
| Frontal-parietal seizures leading hippocampal discharge: | 16.1% | 26.9% | Frontal-parietal cortex | |
| Hippocampal seizures in absence of cortical discharge: | 1.8% | 3.0% | Hippocampus | |
| Hippocampal seizures recruiting only frontal-parietal cortex: | 0.0% | 0.0% | Hippocampus | |
| Hippocampal seizures recruiting neocortex: | 27.4% | 45.7% | Hippocampus | |
| Events simultaneous in cortex and hippocampus: | 40.1% | — | Undefined |
The relative proportion of cortical and hippocampal involvement is shown for each type of seizure (grades 1, 2, 3 and hippocampal). Interaction refers to the reciprocal recruitment of neocortex and hippocampus and it is computed by combining all seizure types and including (w/s.e.) or not (w/o s.e.) events with simultaneous hippocampal and cortical discharge.