Three patients were adults (mean age 43, median age 37), and one was a child (10 years). Two had generalized forms of epilepsy (acquired Lennox-Gastaut Syndrome due to diffuse bilateral polymicrogyria; generalized non-lesional epilepsy characterized by absence and myoclonic seizures). One patient had unilateral hemispheric epilepsy due to dual pathology (adult-onset Rasmussen's encephalitis and focal cortical dysplasia) and prior frontal topectomy. The last patient presented with non-lesional multifocal epilepsy and a history of left parietal topectomy. The DBS for two types of generalized epilepsy targeted bilateral CMN, while the other two targeted bilateral ATN.
Generalized ictal patterns involving the four contacts of both thalamic nuclei have been identified as ictal patterns. In contrast, in hemispheric or multifocal epilepsies, only unilateral thalamic nuclei exhibited ictal EEG changes. Ictal EEG alterations consisted of a combination of rhythmic activity and sharp waves or rhythmic spiking activity. Our figures depict the ictal thalamic recordings with the corresponding ictal thalamic waves.