Complete prefrontal lobe isolation surgery for recurrent epilepsy: A case report

Seizure outcomes of large volume temporo-parieto-occipital and frontal surgery in children with drug-resistant epilepsy

OBJECTIVE

In this study, we investigate the seizure outcomes of temporo-parieto-occipital (TPO) and frontal disconnections or resections in children with drug-resistant epilepsy (DRE) in order to determine factors which may predict surgical results.

METHODS

Children with DRE, who underwent either TPO or frontal disconnection or resection at Great Ormond Street Hospital for Children between 2000 and 2017, were identified from a prospectively collated operative database. Demographic data, age at surgery, type of surgery, scalp EEGs and operative histopathology were collected. Magnetic resonance imaging (MRI) was assessed to determine completeness of disconnection and presence of radiological lesion beyond the disconnection margins. Seizure outcome at 6, 12, and 24 months post-surgery was assessed using the Engel Scale (ES). Logistic regression was used to identify relationships between data variables and seizure outcome.

RESULTS

46 children (males = 28, females = 18; age range 0.5-16.6 years) who underwent TPO (n = 32, including a re-do disconnection) or frontal disconnection or resection (n = 15) were identified. Patients in the TPO treatment group had more favourable seizure outcomes than those in the frontal treatment group (ES I-II in 56 %vs 47 % at 6 months, 52 % vs 46 % at 12 months). Presence of the lesion beyond disconnection boundaries and older age at the time of surgery were associated with poorer seizure outcome. Gender, surgery type, completeness of disconnection, scalp EEG findings and underlying pathology were not related to seizure outcome, but subgroup numbers were small.

CONCLUSIONS

Both TPO and frontal disconnection are effective treatments for selected children with posterior multi-lobar or diffuse frontal lobe epilepsy. Confinement of the MRI lesion within the disconnection margins and a younger age at surgery are associated with favourable seizure outcomes. Further studies are required to elucidate these findings.

Frontal disconnection surgery for drug-resistant epilepsy: Outcome in a series of 16 patients

OBJECTIVE

To evaluate the effectiveness of frontal disconnection surgery in seizure control and related consequences in a consecutive patient series.

METHODS

We conducted a retrospective analysis of patients who underwent frontal disconnection surgery for drug-resistant epilepsy (DRE). Baseline epilepsy characteristics, detailed presurgical evaluation including epileptogenic zone (EZ) localization, magnetic resonance imaging (MRI) detection of epileptogenic lesion, and pathological findings were reviewed. Patients were followed postoperatively for seizure outcome at 1 year.

RESULTS

A total of 16 patients were identified (six children and 10 adults). Most patients had a childhood onset of DRE with a median duration of epilepsy of 6.5 years (interquartile range 3.5-17.5 years) before surgery. In 10 (62.5%) patients, the EZ was localized to the frontal lobe, while in six patients, the EZ involved also adjacent lobes or consisted of multiple foci. In 10 (62.5%) patients, an epileptogenic lesion was detected on presurgical MRI, four of which (40%) had all MRI abnormalities confined to the frontal lobe. Two-thirds of the patients (11/16; 68.8%) underwent isolated frontal disconnection procedure, while remaining patients had frontal disconnection combined with resection of an adjacent lobe. Of the 12 patients in whom biopsy was taken from the disconnected frontal lobe, six (50%) had pathology-proven focal cortical dysplasia. We observed surgical-related complications in three (18.8%) cases, neurological deficits in other three (18.8%) patients, and worsening cognitive abilities in one (6.3%) patient. Overall, eight (50%) patients became completely seizure-free (ILAE 1) at one-year follow-up.

SIGNIFICANCE

Frontal disconnection surgery for DRE can result in seizure freedom in certain patients, especially when the EZ is strictly limited to the ipsilateral frontal region, and the MRI shows an epileptogenic lesion that is purely frontal in location. Frontal lobe disconnection procedure is safe and has a limited complication rate. However, further studies with larger patient population will yield more significance.