Figure 2
Presurgical evaluation and surgical approach in a five-year-old patient with a TSC1 genetic variant. Epilepsy onset occurred at four months of age, with epileptic spasms without clear-cut clinical lateralization. Afterwards, the patient started to present with focal seizures characterized by right head deviation and diffuse tonic contraction (left>right), followed by subtle epileptic spasms (mild head deviation). Psychomotor development was moderately delayed, language was strongly delayed, and autistic features were evident. Video-EEG showed right multifocal continuous interictal epileptiform abnormalities. (A) Intracranial SEEG exploration of the right hemisphere using 18 electrodes: four electrodes (A, B, C, O) were used to explore the frontal lobe, both basal and dorsal surface; six electrodes (D, E, H, I, N, G) for the temporal lobe; and three electrodes (F, L, M) for the posterior parietal area. (B) Preoperative brain MRI showing multiple bilateral tubers with hyperintensity on FLAIR-weighted sequences. (C) Post-operative brain MRI showing that the resection area corresponded to the right fronto-basal region which was identified by the SEEG study. Three years post-surgery, the patient was seizure-free, with improvement in language and interaction. (D) The SEEG recording showing a focal seizure starting with a low-voltage fast discharge over electrodes B, C, O, followed by rhythmic theta activity at the same electrodes and over electrode A; soon after, the ictal discharge involved temporal electrodes (D, E, H, M, N) with spike and spike-and-wave complexes. (E) The focal seizure was followed by a cluster of epileptic spasms characterized by pseudorhythmic complexes of spikes, followed by a high-voltage slow wave, mixed with fast activity evident at electrodes A3-4. The clinical counterpart was subtle (mild bilateral muscular activation on polygraphic traces).