Paediatric epilepsy surgery in the posterior cortex: a study of 62 cases

Abstract

Past surgical series have emphasized the diagnostic complexity of posterior cortex epilepsy. Available data are sparse, especially in children, and most published series report a high number of surgical failures and post‐operative neurological deficits. In this article, we present a paediatric cohort of 62 children who underwent surgery for drug resistant posterior cortex epilepsy before the age of 16 years with a mean post‐operative follow‐up of 6.94 years (range: 2–16). Mean age at epilepsy onset was 3.2 years and 28 children (45%) had onset before 1 year of age. The mean age at surgery was 7.9 years (range: 1–16). Daily seizures were present in 63% of children. MRI was positive in 58 cases (93.5%) and invasive stereo‐EEG was judged mandatory in 24/62 (39%) of patients. Surgery was confined to the parietal lobe in 11 children, the occipital lobe in 8, the occipito‐parietal region in four, the occipito‐temporal region in 18, and involved both the temporal and parietal lobes in the remaining 21. Following surgery, 53 subjects (85.5%) remained seizure‐free and among those who underwent a SEEG procedure, 75% achieved seizure freedom. Focal cortical dysplasia was the most frequent histopathological diagnosis (50%), followed by tumoural (24%) and gliotic lesions (14.5%). An older age at epilepsy onset, the presence of a rather restricted epileptogenic area, and a complete resection of the epileptogenic zone were predictive of a favourable surgical outcome. These results demonstrate that a good surgical outcome is possible in children with drug resistant posterior cortex epilepsy. Accurate analysis of the chronology of ictal semiology and electrophysiological features, viewed in the context of the complete electroclinical pattern, provides a topographical orientation for posterior cortex epilepsy and, together with the presence of a lesion detectable on imaging, may improve the rate of surgical success of posterior cortex epilepsy at paediatric age.

Drug‐resistant parietal lobe epilepsy: clinical manifestations and surgery outcome

“…Our study showed that scalp EEG monitoring is often misleading or non‐localizing in patients with PLE. This finding has also been observed in previous studies (Cascino et al ., ; Salanova et al ., ; Kim et al ., ; Binder et al ., ; Bartolomei et al ., ; Liava et al ., ; Francione et al ., ) ( table ). Interictal and ictal scalp EEG recordings in patients with PLE have lower localizing value compared with temporal lobe epilepsy patients (Ristic et al ., ).…”

“…Similarly, other aura types, including those often attributed to other lobes ( e.g . epigastric aura), could be seen in patients with PLE (Tufenkjian and Lüders, ; Liava et al ., ; Francione et al ., ). There is no pathognomonic clinical manifestation in patients with PLE.…”

“…Parietal lobe epilepsy (PLE) accounts for approximately 5% of all focal epilepsies (Salanova, ). The parietal lobe has rich connections with the adjacent lobes (Akimura et al ., ; Kamali et al ., ) and as a consequence, clinical symptoms and seizure semiology in PLEs are diverse and the EEG findings are often mislocalizing (Salanova et al ., ; Binder et al ., ; Ristic et al ., ; Liava et al ., ; Francione et al ., ).…”

Recent developments in the surgical management of paediatric epilepsy

“…Liava et al 25 described 62 children with DRE and focal seizures from the posterior cerebral cortex, including 24 patients in whom SEEG facilitated localisation of the epileptogenic zone. Among patients who underwent SEEG, 75% achieved seizure freedom.…”

Temporal lobe epilepsy? Things are not always what they seem

“…This patient is a typical example of what has been described as pseudo‐temporal epilepsy, in which seizures start in extra‐temporal lobe structures and later spread over the temporal lobe region, therefore mimicking temporal semiology (Andermann, ). Extra‐temporal lobe regions include the orbito‐frontal cortex (Shihabuddin et al ., ), the insula (Isnard et al ., ), and the parieto‐occipital regions (Williamson et al ., ; Palmini et al ., ; Liava et al ., ; Francione et al ., ), especially the posterior cingulate (Devinsky et al ., ; Alkawadri et al ., ; Enatsu et al ., ). Alkawadri et al .…”