Clinical characteristics and epilepsy outcomes following surgery caused by focal cortical dysplasia (type IIa) in 110 adult epileptic patients

Seizure Outcome After Intraoperative Electrocorticography-Tailored Epilepsy Surgery: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Tailoring epilepsy surgery using intraoperative electrocorticography (ioECoG) has been debated, and modest number of epilepsy surgery centers apply this diagnostic method. We assessed the current evidence to use ioECoG-tailored epilepsy surgery for improving postsurgical outcome.

METHODS

PubMed and Embase were searched for original studies reporting on ≥10 cases who underwent ioECoG-tailored surgery for epilepsy, with a follow-up of at least 6 months. We used a random-effects model to calculate the overall rate of patients achieving favorable seizure outcome (FSO), defined as Engel class I, ILAE class 1, or seizure-free status. Meta-regression was used to investigate potential sources of heterogeneity. We calculated the odds ratio (OR) for estimating variables on FSO:ioECoG vs non-ioECoG-tailored surgery (if included studies contained patients with non-ioECoG-tailored surgery), ioECoG-tailored epilepsy surgery in children vs adults, temporal (TL) vs extratemporal lobe (eTL), MRI-positive vs MRI-negative, and complete vs incomplete resection of tissue that generated interictal epileptiform discharges (IEDs). A Bayesian network meta-analysis was conducted for underlying pathologies. We assessed the evidence certainty using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE).

RESULTS

Eighty-three studies (82 observational studies, 1 trial) comprising 3,631 patients with ioECoG-tailored surgery were included. The overall pooled rate of patients who attained FSO after ioECoG-tailored surgery was 74% (95% CI 71-77) with significant heterogeneity, which was predominantly attributed to pathologies and seizure outcome classifications. Twenty-two studies contained non-ioECoG-tailored surgeries. IoECoG-tailored surgeries reached a higher rate of FSO than non-ioECoG-tailored surgeries (OR 2.10 [95% CI 1.37-3.24]; p < 0.01; very low certainty). Complete resection of tissue that displayed IEDs in ioECoG predicted FSO better compared with incomplete resection (OR 3.04 [1.76-5.25]; p < 0.01; low certainty). We found insignificant difference in FSO after ioECoG-tailored surgery in children vs adults, TL vs eTL, or MRI-positive vs MRI-negative. The network meta-analysis showed that the odds of FSO was lower for malformations of cortical development than for tumors (OR 0.47 95% credible interval 0.25-0.87).

DISCUSSION

Although limited by low-quality evidence, our meta-analysis shows a relatively good surgical outcome (74% FSO) after epilepsy surgery with ioECoG, especially in tumors, with better outcome for ioECoG-tailored surgeries in studies describing both and better outcome after complete removal of IED areas.

Stereo-electroencephalography (SEEG)-Guided Surgery in Epilepsy With Cingulate Gyrus Involvement: Electrode Implantation Strategies and Postoperative Seizure Outcome

SUMMARY

Surgical treatment of cingulate gyrus epilepsy is associated with good results on seizures despite its rarity and challenging aspects. Invasive EEG monitoring is often mandatory to assess the epileptogenic zone in these patients. To date, only small surgical series have been published, and a consensus about management of these complex cases did not emerge. The authors retrospectively analyzed a large surgical series of patients in whom at least part of the cingulate gyrus was confirmed as included in the epileptogenic zone by means of stereo-electroencephalography and was thus resected. One hundred twenty-seven patients were selected. Stereo-electroencephalography-guided implantation of intracerebral electrodes was performed in the right hemisphere in 62 patients (48.8%) and in the left hemisphere in 44 patients (34.7%), whereas 21 patients (16.5%) underwent bilateral implantations. The median number of implanted electrodes per patient was 13 (interquartile range 12-15). The median number of electrodes targeting the cingulate gyrus was 4 (interquartile range 3-5). The cingulate gyrus was explored bilaterally in 19 patients (15%). Complication rate was 0.8%. A favorable outcome (Engel class I) was obtained in 54.3% of patients, with a median follow-up of 60 months. The chance to obtain seizure freedom increased in cases in whom histologic diagnosis was type-IIb focal cortical dysplasia or tumor (mostly ganglioglioma or dysembryoplastic neuroepithelial tumor) and with male gender. Higher seizure frequency predicted better outcome with a trend toward significance. Our findings suggest that stereo-electroencephalography is a safe and effective methodology in achieving seizure freedom in complex cases of epilepsy with cingulate gyrus involvement.

Clinical characteristics and surgical outcomes in children with mild malformation of cortical development and oligodendroglial hyperplasia in epilepsy

OBJECTIVE

Mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE) is a new and rare histopathological entity of cortical developmental malformations. The clinical characteristics of MOGHE remain challenging.

METHODS

Children with histologically confirmed MOGHE were retrospectively studied. The clinical findings, electroclinical and imaging features, and postoperative outcomes were analyzed, and previously published studies were reviewed up to June 2022.

RESULTS

Thirty-seven children were included in our cohort. Clinical characteristics included early onset in infancy (94.6% before 3 years), multiple seizure types, and moderate or severe delay. Epileptic spasm is the most common seizure type and initial manifestation. The lesions were mainly multilobar (59.5% multiple lobes and 8.1% hemispheres), and predominance in the frontal lobe was observed. The interictal EEG pattern was circumscribed or widespread. The prominent MRI characteristics were cortical thickening, cortical/subcortical hyperintense T2/FLAIR signal, and blurring at the GM and WM transition. Among the 21 children followed up for more than 1 year after surgery, 76.2% were seizure-free. Preoperative interictal circumscribed discharges and larger resections were significantly associated with a good postoperative outcome. The clinical features of 113 patients in the reviewed studies were similar to those we reported, but the lesions were mainly unilobar (73.5%) and Engel I was achieved in only 54.2% after surgery.

SIGNIFICANCE

Distinct clinical characteristics in MOGHE, especially age at onset, epileptic spasm, and age-related MRI characteristics, can help in early diagnosis. Preoperative interictal discharge and surgical strategy may be predictors of postoperative outcomes.

[The structural basis of epileptogenesis in an adult patient: the comprehensive diagnostics experience]

On the example of the diagnosis of the structural basis of focal epilepsy in an adult patient, the possibilities of a multimodal and interdisciplinary approach to diagnosis, combining the latest methods of neuroimaging with the results of neurophysiological examinations, are considered. The interaction and high qualification of specialists in epileptology, neuroradiology and pathomorphology provide a high probability to determine the cause of the focal forms of epilepsy. Along with the introduction of super-inductive MR systems, it is important to use their capabilities correctly and optimize the scanning protocol for the individual characteristics of the patient. With a long-term pharmacoresistant course of focal epilepsy, accompanied by low quality of life, the progression of neurological deficits and the aggravation of cognitive and personality problems in patients, it becomes obvious that these patients, even with negative results of standard MRI, are candidates for a more in-depth comprehensive examination to identify the structural basis of epileptogenesis and subsequent epileptic surgery. However, the problem of epilepsy pseudoresistance should be considered, when a patient with uncontrolled seizures takes antiepileptic drugs for a long time in inadequate dosages. Modern comprehensive diagnostics offers new rational approaches to antiepileptic therapy indication on the part of the doctor, as well as to improve the patient's compliance to the treatment.

Post-Surgical Outcome and Its Determining Factors in Patients Operated on With Focal Cortical Dysplasia Type II-A Retrospective Monocenter Study

Purpose: Focal cortical dysplasias (FCDs) are a frequent cause of drug-resistant focal epilepsies. These lesions are in many cases amenable to epilepsy surgery. We examined 12-month and long-term post-surgical outcomes and its predictors including positive family history of epilepsy.

Methods: Twelve-month and long-term outcomes regarding seizure control after epilepsy surgery in patients operated on with FCD type II between 2002 and 2019 in the Epilepsy Center of Bonn were evaluated based on patient records and telephone interviews.

Results: Overall, 102 patients fulfilled the inclusion criteria. Seventy-one percent of patients at 12 months of follow-up (FU) and 54% of patients at the last available FU (63 ± 5.00 months, median 46.5 months) achieved complete seizure freedom (Engel class IA), and 84 and 69% of patients, respectively, displayed Engel class I outcome. From the examined variables [histopathology: FCD IIA vs. IIB, lobar lesion location: frontal vs. non-frontal, family history for epilepsy, focal to bilateral tonic–clonic seizures (FTBTCS) in case history, completeness of resection, age at epilepsy onset, age at surgery, duration of epilepsy], outcomes at 12 months were determined by interactions of age at onset, duration of epilepsy, age at surgery, extent of resection, and lesion location. Long-term post-surgical outcome was primarily influenced by the extent of resection and history of FTBTCS. Positive family history for epilepsy had a marginal influence on long-term outcomes only.

Conclusion: Resective epilepsy surgery in patients with FCD II yields very good outcomes both at 12-month and long-term follow-ups. Complete lesion resection and the absence of FTBTCS prior to surgery are associated with a better outcome.

Clinical features and surgical outcomes in young children with focal cortical dysplasia type II

AIMS

To investigate clinical characteristics and surgery outcomes of young children with focal cortical dysplasia (FCD) type II.

METHODS

Young children (onset age ≤6 years) with FCDII who underwent epileptic surgery in Children Epilepsy Center of Peking University First Hospital in 2014-2018 were followed up for at least 6 months after surgery.

RESULTS

One hundred and twelve children with FCDII were included, with median age of onset 0.9 years (0.01-5.9), who underwent surgery at 4.1 years old (0.8-16.2). Focal seizures were most frequent (90.2%) and epileptic spasms presented in 23 (20.5%) cases. Epileptic encephalopathy was not uncommon (12.5%), associated with earlier epilepsy onset and higher rate of bilateral onset on ictal EEG (OR = 0.213, 9.059; P = .041, .004). At the last follow-up, 88.4% achieved seizure-free. Before surgery, 49.1% showed moderate/severe developmental delay, associated with earlier seizure onset and higher rate of history of epileptic encephalopathy (OR = 0.740, 5.160, P = .023, .042). For 48 children with preoperatively moderate/severe developmental delay, DQ rank at 6 months postsurgery was improved in only four cases.

CONCLUSION

For young children with FCDII, they tend to present with epileptic encephalopathies and show moderate/severe developmental delay before surgery. The seizure outcome was favorable after surgery. For children with preoperatively moderate/severe developmental delay, developmental outcome at 6 months after surgery was not satisfactory.