Clinical and chronotopographic psychomotor seizure patterns (SEEG study with reference to postoperative results)

In 29 selected patients who underwent stereo-electroencephalographic exploration because of uncontrolled psychomotor epilepsy, 213 seizures were recorded. These seizures were analyzed in 10-second-intervals with respect to the sequence of clinical signs and the electrical chronotopographic patterns. By the aid of a computerized cluster analysis four comparatively distinct localization-patterns were found: a) opercular, b) frontobasal-cingular, c) temporobasal-limbic and d) posterior temporal neocortical. The lowest trend for propagation to the opposite hemisphere is found in a) followed by d). Fairly strong tendency for contralateral propagation is seen in c). Strategically important structures for contralateral propagation are: 1. amygdala and hippocampus, and to a lesser degree 2. the frontal cortex. Seizures propagating to the parietal cortex very often involve the frontal area of the same side before affecting the opposite hemisphere. For each of these "epileptic clusters" the characteristic clinical signs are pointed out. Special emphasis was put on the primictal symptom-sequence. By this and a similar study with Bancaud et al. we show that significantly better postoperative results are found, when strategy for surgery was based on the evidence of several SEEG recorded spontaneous seizures. In some patients belonging to the "temporobasal-limbic" cluster stereotactic procedures proved successful.