Surgical outcomes and prognostic factors of drug-resistant epilepsy secondary to encephalomalacia

Clinical characteristics of cystic encephalomalacia in children

Purpose

To investigate the primary causes and clinical characteristics of cystic encephalomalacia (CE) in children.

Methods

The clinical data of 50 children who were admitted to our hospital due to CE between January 2008 and December 2020 were retrospectively reviewed. Their primary causes, clinical manifestations and cranial magnetic resonance imaging features were analyzed.

Results

Among all patients, 5 had prematurity, 19 had hypoxic-ischemic encephalopathy (HIE), 13 had intracranial infection, 14 had traumatic brain injury and hemorrhage, 4 had cerebral infarction, 2 had congenital genetic diseases, and 1 had hypoglycemia. The average time from primary disease onset to CE diagnosis was 70.1 ± 61.0 days. The clinical manifestations included speech or motor developmental delay (n = 33), epilepsy (n = 31), dystonia (n = 27), limb paralysis (n = 16), and visual or auditory impairment (n = 5). Patients with HIE as the primary cause of CE had a significantly higher occurrence of dystonia, while a significantly higher incidence of paralysis was observed in those with cerebral infarction as the primary cause.

Conclusion

CE in children is mainly caused by HIE, intracranial infection, and cerebral hemorrhage. The major clinical manifestations included speech or motor developmental delay, epilepsy, and dystonia. Magnetic resonance imaging is an important tool for the diagnosis of CE.

Surgical treatment for drug-resistant epilepsy due to early brain injury in children

BACKGROUND

The study aimed to summarize the indications and clinical features of pediatric drug-resistant epilepsy associated with early brain injury, surgical outcomes, and prognostic factors.

METHODS

We retrospectively analyzed children diagnosed with drug-resistant epilepsy due to early brain injury, who had undergone surgery at the Pediatric Epilepsy Center of Peking University First Hospital from May 2014 to May 2021. Clinical data of vasculogenic and non-vasculogenic injuries from early brain damage were compared and analyzed. The surgical outcomes were assessed using the Engel grading system.

RESULTS

The median ages at acquiring injury, seizure onset, and surgery among 65 children were 19.0 (0-120) days, 8.6 (0-136.5) months, and 62.9 (13.5-234) months, respectively. Of the 14 children with non-vasculogenic injuries, 12 had posterior ulegyria. Unilateral or bilateral synchronous interictal epileptiform discharges were located mainly in the posterior quadrant in 10 children (71 %), and unilateral posterior quadrant or non-lateralized ictal region in eight children (57 %). The surgical approach was mainly temporo-parieto-occipital or parieto-occipital disconnection in nine children. Of 49 children with vasculogenic injuries, magnetic resonance imaging revealed hemispheric abnormalities in 38. Unilaterally hemispheric or bilateral interictal epileptiform discharges were observed in 36 children (73 %), whereas 42 (86 %) had unilateral hemispheric or non-lateralized ictal onset. The surgical procedure involved hemispherotomy in 38 children (78 %) and lobectomy or disconnection, multilobectomy or disconnection and hemispherotomy in 5, 20, and 40 children, respectively. Fifty-five patients (84.6 %) achieved remission from seizure during follow-up at 5.4 years. Age at surgery (odds ratio = 1.022, 95 % confidence interval = 1.003-1.042, P = 0.023) and etiology (odds ratio = 17.25, 95 % confidence interval = 2.778-107.108, P = 0.002) affected the seizure outcomes.

CONCLUSION

Children with drug-resistant epilepsy due to early brain injury can successfully be treated with surgery after rigorous preoperative screening. Good surgical outcomes are associated with an early age at surgery and an etiology of vasculogenic injury.

Vagus nerve stimulation for pharmacoresistant epilepsy secondary to encephalomalacia: A single-center retrospective study

Objective

Vagus nerve stimulation (VNS) is an adjunctive treatment for pharmacoresistant epilepsy. Encephalomalacia is one of the most common MRI findings in the preoperative evaluation of patients with pharmacoresistant epilepsy. This is the first study that aimed to determine the effectiveness of VNS for pharmacoresistant epilepsy secondary to encephalomalacia and evaluate the potential predictors of VNS effectiveness.

Methods

We retrospectively analyzed the seizure outcomes of VNS with at least 1 year of follow-up in all patients with pharmacoresistant epilepsy secondary to encephalomalacia. Based on the effectiveness of VNS (≥50% or <50% reduction in seizure frequency), patients were divided into two subgroups: responders and non-responders. Preoperative data were analyzed to screen for potential predictors of VNS effectiveness.

Results

A total of 93 patients with epilepsy secondary to encephalomalacia who underwent VNS therapy were recruited. Responders were found in 64.5% of patients, and 16.1% of patients achieved seizure freedom at the last follow-up. In addition, the responder rate increased over time, with 36.6, 50.5, 64.5, and 65.4% at the 3-, 6-, 12-, and 24-month follow-ups, respectively. After multivariate analysis, seizure onset in adults (>18 years old) (OR: 0.236, 95%CI: 0.059-0.949) was found to be a positive predictor, and the bilateral interictal epileptic discharges (IEDs) (OR: 3.397, 95%CI: 1.148-10.054) and the bilateral encephalomalacia on MRI (OR: 3.193, 95%CI: 1.217-8.381) were found to be negative predictors of VNS effectiveness.

Conclusion

The results demonstrated the effectiveness and safety of VNS therapy in patients with pharmacoresistant epilepsy secondary to encephalomalacia. Patients with seizure onset in adults (>18 years old), unilateral IEDs, or unilateral encephalomalacia on MRI were found to have better seizure outcomes after VNS therapy.

Screening of Risk Factors for Poor Prognosis in Patients with Refractory Epilepsy Secondary to Encephalomalacia

Objective

The study was aimed at screening the independent prognostic risk factors for refractory epilepsy associated with encephalomalacia (REAE).

Methods

Patients with REAE treated in the First People's Hospital of Linping District from January 2018 to December 2019 were selected. The prognosis was represented by Engel grading. Clinical data of the patients were collected, including age, sex, BMI, lesion sites, number of lesion sites, lesion size, seizure frequency, epilepsy type, and treatment methods. Independent risk factors for poor prognosis were screened by logistic regression analysis. The receiver operating characteristic curve (ROC) was used to evaluate the prognostic efficacy of independent risk factors.

Results

A total of 48 patients were included in this study, including 31 patients (64.58%) in the good prognosis group and 17 patients (35.42%) in the poor prognosis group. The mean age of the poor prognosis group was higher than that of the good prognosis group (P = 0.002). The proportion of patients with multisite lesions in the poor prognosis group was higher than that in the good prognosis group (P = 0.016). The proportion of patients with cerebral malacia lesion diameter ≥ 3 cm in the poor prognosis group was higher than that in the good prognosis group (P = 0.002). The proportion of patients with attack frequency ≥ 2 times/month in the poor prognosis group was higher than in the good prognosis group (P = 0.002). The proportion of patients receiving surgical treatment in the poor prognosis group was lower than that in the good prognosis group (P < 0.001). Age, number of lesion sites, size of encephalomalacia, and seizure frequency were independent risk factors for the prognosis of patients with REAE (OR > 1, P < 0.05). Surgical treatment was an independent protective factor associated with the prognosis of patients with REAE (OR < 1, P < 0.05). The area under the ROC curve of surgical treatment was 0.83 (P = 0.004). The area under the ROC curve of the size of encephalomalacia was 0.72 (P = 0.008). There was a positive correlation between age and size of encephalomalacia and Engel grade (r > 0, P < 0.05). Surgical treatment was negatively correlated with Engel grade (r < 0, P < 0.05). The number of lesion sites and seizure frequency had no significant correlation with Engel (P > 0.05). The proportion of Engel I patients treated with surgery was higher than that treated with drugs (P = 0.001). The ratio of Engel III and IV patients treated with surgery was lower than that treated with medications (P < 0.05).

Conclusion

Age, number of lesion sites, size of encephalomalacia, and seizure frequency are independent risk factors for the prognosis of patients with REAE. Surgical treatment is an independent prognostic factor for patients with REAE. Surgical treatment can significantly improve patient outcomes.

Focal cortical dysplasia links to sleep-related epilepsy in symptomatic focal epilepsy

OBJECTIVE

In sleep-related epilepsy (SRE), epileptic seizures predominantly occur during sleep, but the clinical characteristics of SRE remain elusive. We aimed to identify the clinical features associated with the occurrence of SRE in a large cohort of symptomatic focal epilepsy.

METHODS

We retrospectively included patients with four etiologies, including focal cortical dysplasia (FCD), low-grade tumors (LGT), temporal lobe epilepsy with hippocampal sclerosis (TLE-HS), and encephalomalacia. SRE was defined as more than 70% of seizures occurring during sleep according to the seizure diary. The correlation between SRE and other clinical variables, such as etiology of epilepsy, pharmacoresistance, seizure frequency, history of bilateral tonic-clonic seizures, and seizure localization was analyzed.

RESULTS

A total of 376 patients were included. Among them 95 (25.3%) were classified as SRE and the other 281(74.7%) as non-SRE. The incidence of SRE was 53.5% in the FCD group, which was significantly higher than the other three groups (LGT: 19.0%; TLE-HS: 9.9%; encephalomalacia: 16.7%; P < 0.001). The etiology of FCD (p < 0.001) was significantly associated with SRE (OR: 9.71, 95% CI: 3.35-28.14) as an independent risk factor. In addition, small lesion size (p = 0.009) of FCD further increased the risk of SRE (OR: 3.18, 95% CI: 1.33-7.62) in the FCD group.

SIGNIFICANCE

Our data highlight that FCD markedly increased the risk of sleep-related epilepsy independently of seizure localization. A small lesion of FCD further increased the risk of sleep-related epilepsy by 2.18 times in the FCD group.

The impact of MEG results on surgical outcomes in patients with drug-resistant epilepsy associated with focal encephalomalacia: a single-center experience

PURPOSE

To analyze the impact of magnetoencephalography (MEG) results on surgical outcomes in patients with drug-resistant epilepsy secondary to encephalomalacia.

METHODS

We retrospectively reviewed 121 patients with drug-resistant epilepsy associated with encephalomalacia who underwent MEG followed by resection surgery. Patients were subdivided into concordant MEG group and dis-concordant MEG group for analysis based on whether the MEG results were in concordance with epileptogenic zones or not.

RESULTS

121 patients were included in the present study. The MEG spike sources of 73 (60.33%) patients were in concordance with epileptogenic zones while the MEG spike sources of the other 48 (39.67%) were in dis-concordance with epileptogenic zones. Favorable seizure outcomes were achieved in 79.45% (58 of 73) of patients with concordant MEG results while only 62.50% (30 of 48) of patients with dis-concordant MEG results were seizure free with a follow-up of 2-10 years. The differences of seizure-free rate between patients with concordant MEG results and dis-concordant MEG results were statistically significant. For patients with concordant MEG results, bilateral lesions on MRI are the only independent predictor of unfavorable seizure outcomes. For patients with discordant MEG results, duration of seizures is the only independent predictor of unfavorable seizure outcomes.

CONCLUSIONS

Concordant MEG results are associated with favorable seizure outcomes. Bilateral lesions on MRI independently predict unfavorable seizure outcomes in patients with concordant MEG results while longer seizure durations independently predict unfavorable seizure outcomes in patients with dis-concordant MEG results.