Long-term seizure outcomes in patients with drug resistant epilepsy

Predictors of medical intractability in children with epilepsy onset during the first two years of life, excluding infantile epileptic spasm syndrome

PURPOSE

Early childhood epilepsy presents a significant challenge, with approximately 30 % of individuals experiencing treatment failure. This study aimed to identify predictors of medical intractability in children with epilepsy onset during the first two years of life, excluding infantile epileptic spasm syndrome.

METHODS

A total of 323 children were retrospectively evaluated. The analyses included a review of medical records for demographic, laboratory, radiological, and electroencephalographic (EEG) findings. Children were diagnosed with drug-resistant epilepsy (DRE) according to the ILAE diagnostic criteria. Twenty-one potential prognostic predictors were examined in relation to medical intractability.

RESULTS

Among the 323 children (56.7 % male), 119 (36.8 %) had unknown epilepsy, 131 (40.6 %) had structural epilepsy, 53 (16.4 %) had genetic epilepsy, and 20 (6.2 %) had metabolic epilepsy. Over a median follow-up of 68 months, 55.4 % of the children achieved ≥6 months of seizure freedom, 33.1 % developed DRE, and the remaining 11.5 % had rare ongoing seizures but did not meet the criteria for DRE because they were only treated with one antiseizure medication at the last follow-up. Univariate logistic regression analyses identified ten risk factors significantly associated with DRE. Multivariate logistic regression analyses revealed that the presence of developmental delay at epilepsy onset (p = 0.000; OR 7.890; 95 %CI 2.713 to 22.945), history of status epilepticus (p = 0.000; OR 8.247; 95 %CI 3.619 to 18.793), number of antiseizure medications (ASMs) at the sixth month of diagnosis (p = 0.000; OR 20.585; 95 %CI 8.993 to 47.117), and initial EEG findings (p = 0.046; OR 2.366; 95 %CI 1.015 to 5.518) were predictors of medical intractability. Nineteen (5.9 %) children died during follow-up for various reasons, including progressive neurogenetic or neurodegenerative disorders.

CONCLUSION

Developmental delay at epilepsy onset, a history of status epilepticus, the use of two or more ASMs in the sixth month of diagnosis, and abnormal initial EEG findings were associated with medical intractability.

Downregulation of Ubiquitin-Specific Protease 15 (USP15) Does Not Provide Therapeutic Benefit in Experimental Mesial Temporal Lobe Epilepsy

Structural epilepsies display complex immune activation signatures. However, it is unclear which neuroinflammatory pathways drive pathobiology. Transcriptome studies of brain resections from mesial temporal lobe epilepsy (mTLE) patients revealed a dysregulation of transforming growth factor β, interferon α/β, and nuclear factor erythroid 2-related factor 2 pathways. Since these pathways are regulated by ubiquitin-specific proteases (USP), in particular USP15, we hypothesized that USP15 blockade may provide therapeutic relief in treatment-resistant epilepsies. For validation, transgenic mice which either constitutively or inducibly lack Usp15 gene expression underwent intrahippocampal kainate injections to induce mTLE. We show that the severity of status epilepticus is unaltered in mice constitutively lacking Usp15 compared to wild types. Cell death, reactive gliosis, and changes in the inflammatory transcriptome were pronounced at 4 days after kainate injection. However, these brain inflammation signatures did not differ between genotypes. Likewise, induced deletion of Usp15 in chronic epilepsy did not affect seizure generation, cell death, gliosis, or the transcriptome. Concordantly, siRNA-mediated knockdown of Usp15 in a microglial cell line did not impact inflammatory responses in the form of cytokine release. Our data show that a lack of USP15 is insufficient to modulate the expression of relevant neuroinflammatory pathways in an mTLE mouse model and do not support targeting USP15 as a therapeutic approach for pharmacoresistant epilepsy.

Standardized hierarchical adaptive Lp regression for noise robust focal epilepsy source reconstructions

OBJECTIVE

To investigate the ability of standardization to reduce source localization errors and measurement noise uncertainties for hierarchical Bayesian algorithms with L1- and L2-norms as priors in electroencephalography and magnetoencephalography of focal epilepsy.

METHODS

Description of the standardization methodology relying on the Hierarchical Bayesian framework, referred to as the Standardized Hierarchical Adaptive Lp-norm Regularization (SHALpR). The performance was tested using real data from two focal epilepsy patients. Simulated data that resembled the available real data was constructed for further localization and noise robustness investigation.

RESULTS

The proposed algorithms were compared to their non-standardized counterparts, Standardized low-resolution brain electromagnetic tomography, Standardized Shrinking LORETA-FOCUSS, and Dynamic statistical parametric maps. Based on the simulations, the standardized Hierarchical adaptive algorithm using L2-norm was noise robust for 10 dB signal-to-noise ratio (SNR), whereas the L1-norm prior worked robustly also with 5 dB SNR. The accuracy of the standardized L1-normed methodology to localize focal activity was under 1 cm for both patients.

CONCLUSIONS

Numerical results of the proposed methodology display improved localization and noise robustness. The proposed methodology also outperformed the compared methods when dealing with real data.

SIGNIFICANCE

The proposed standardized methodology, especially when employing the L1-norm, could serve as a valuable assessment tool in surgical decision-making.

Short and long term prediction of seizure freedom in drug-resistant focal epilepsy surgery

BACKGROUND

The selection of candidates for drug-resistant focal epilepsy surgery is essential to achieve the best post-surgical outcomes.

OBJECTIVE

To develop two prediction models for seizure freedom in the short and long-term follow-up and from them to create a risk calculator in order to individualize the selection of candidates for surgery and future therapies in each patients.

METHODS

A sample of 64 consecutive patients who underwent epilepsy surgery at two Cuban tertiary health institutions between 2012 and 2020 constituted the basis for the prediction models. Two models were obtained through the novel methodology, based on biomarker selection reached by resampling methods, cross-validation and high-accuracy index measured through the area under the receiving operating curve (ROC) procedure.

RESULTS

The first, to pre-operative model included five predictors: epilepsy type, seizures per month, ictal pattern, interictal EEG topography and normal or abnormal magnetic resonance imaging,. it's precision was 0.77 at one year, and with four years and more 0.63. The second model including variables from the trans-surgical and post-surgical stages: the interictal discharges in the post-surgical EEG, incomplete or complete resection of the epileptogenic zone, the surgical techniques employed and disappearance of the discharge in post-resection electrocorticography; the precision of this model was 0.82 at one year, and with four years and more 0.97.

CONCLUSIONS

The introduction of trans-surgical and post-surgical variables increase the prediction of the pre-surgical model. A risk calculator was developed using these prediction models, which could be useful as an accurate tool to improve the prediction in epilepsy surgery.

Psychogenic Nonepileptic Seizures-High Mortality Rate Is a 'Wake-Up Call'

Patients with epilepsy have an elevated mortality rate compared to the general population and now studies are showing a comparable death ratio in patients diagnosed with psychogenic nonepileptic seizures. The latter is a top differential diagnosis for epilepsy and the unexpected mortality rate in these patients underscores the importance of an accurate diagnosis. Experts have called for more studies to elucidate this finding but the explanation is already available, embedded in the existing data. To illustrate, a review of the diagnostic practice in epilepsy monitoring units, of the studies examining mortality in PNES and epilepsy patients, and of the general clinical literature on the two populations was conducted. The analysis reveals that the scalp EEG test result, which distinguishes a psychogenic from an epileptic seizure, is highly fallible; that the clinical profiles of the PNES and epilepsy patient populations are virtually identical; and that both are dying of natural and non-natural causes including sudden unexpected death associated with confirmed or suspected seizure activity. The recent data showing a similar mortality rate simply constitutes more confirmatory evidence that the PNES population consists largely of patients with drug-resistant scalp EEG-negative epileptic seizures. To reduce the morbidity and mortality in these patients, they must be given access to treatments for epilepsy.

Anticonvulsant effect of quercetin in pentylenetetrazole (PTZ)-induced seizures in male mice: The role of anti-neuroinflammatory and anti-oxidative stress

BACKGROUND

Epilepsy is one of the major neurological disorders. The inflammatory process and oxidative stress are closely related to seizure progression. Quercetin is a flavonoid with anti-inflammatory and antioxidant properties as well as neuroprotective effects. We aimed to evaluate the effect of quercetin on pentylenetetrazole- (PTZ-) induced seizures in male mice focusing on its possible anti-neuroinflammatory and anti-oxidative stress.

METHODS

In this study, 50 male NMRI mice were divided into five groups (n = 10) and given the following treatments: normal saline, quercetin at doses of 10, 20, and 40 mg/kg, and diazepam at a dose of 10 mg/kg. In order to induce seizures, PTZ was administered intravenously. Drugs were administered intravenously 60 min before the seizure induction. The seizure threshold was measured, and finally, malondialdehyde (MDA), total antioxidant capacity (TAC), and the gene expression of IL-1β, TNF-α, NLRP3, and iNOS were determined in the prefrontal cortex.

RESULTS

It was confirmed that quercetin increased the seizure threshold. And quercetin increased TAC, and decreased levels of MDA as well as gene expression of TNF- α, NLRP3, IL-1β, and iNOS in the prefrontal cortex at the time of seizure induction.

CONCLUSION

It was suggested that the anticonvulsant effect of quercetin in PTZ-induced seizures in mice may be due to the reduction of inflammatory responses and oxidative stress in the prefrontal cortex.

Factors associated with initiation of the modified Atkins diet in adults with drug-resistant epilepsy

Ketogenic diets are promising therapies for drug-resistant epilepsy (DRE). Diet adherence is a major concern in adults, so a less restrictive diet like the modified Atkins diet (MAD) is preferred. The objective of this study was to explore factors associated with MAD initiation in adults with DRE. It is a retrospective cohort study that includes participants aged ≥ 16 years with at least two failing antiseizure medications (ASM). We compared clinical and demographic variables between those patients who initiated the MAD and those who did not. A total of 136 patients were included and 52 participants initiated a MAD. After 3 months, only 28 patients (58%) continued on the MAD. For those who initiated a MAD trial: 1) the average number of current ASMs (3 ± 1 vs 2 ± 1, p < 0.008) and the average lifetime ASMs (6 ± 3 vs 5 ± 2, p < 0.008) was higher, 2) they had an earlier age of epilepsy onset (9 vs 13 years, p < 0.006) and 3) there was a greater proportion of patients with a history of status epilepticus (OR = 3.89, 95% CI = 1.16-13.01). In contrast, temporal lobe epilepsy onset had a negative association with MAD trial initiation (OR = 0.32, 95% CI = 0.12-0.88). In conclusion, five factors are associated with MAD initiation in adults with DRE. Chronic DRE may be the major motivation for MAD initiation. Nonetheless, adults with a history of status epilepticus could be a target population to initiate the MAD early.

Individuals who develop drug-resistant epilepsy within a year after initial diagnosis have higher burden of mental and physical diseases one-year prior to epilepsy diagnosis as compared to those whose seizures were controlled during the same interval

INTRODUCTION

Epilepsy is a neurological disease characterized by recurrent, unprovoked seizures and its impact on biological, cognitive, psychological, and social outcomes. An unmet need for finding effective treatment options exists. Identifying medical diagnoses present prior to a diagnosis of epilepsy is an important step in increasing our understanding of how people with epilepsy may respond to therapy, help guide clinicians in managing associated comorbid conditions, and inform future research.

METHODS

A population-based retrospective comparative cohort study was conducted using administrative claims data to explore differences in medical diagnoses prior to an initial diagnosis of epilepsy between patients with and without drug-resistant epilepsy (DRE) identified within one-year post diagnosis by evaluating standardized mean differences between the groups.

RESULTS

A total of 205,183 patients with newly diagnosed epilepsy were identified. Of those, 4.1% (n = 8340) were considered drug resistant one-year post diagnosis. Pain and mood disorders were the common physical and psychiatric diagnoses in both cohorts. Differences between the newly diagnosed epilepsy and DRE cohorts were observed. Patients in the DRE cohort were younger, had more encounters with the healthcare system, and higher burden of disease for both physical (e.g., headache, neuropathy, muscular-skeletal disorders, and traumatic brain injury) and psychiatric diagnoses (e.g., depression, anxiety, bipolar disorder, suicidal thoughts, drug dependency, and sleep disorders).

CONCLUSION

Physical and psychiatric diagnoses are common one year prior to first diagnosis of epilepsy in administrative claims data. Compared to patients without DRE, those who develop DRE within one-year post initial diagnosis demonstrated a higher burden of disease.

Predictive factors of Status Epilepticus and its recurrence in patients with adult-onset seizures: A multicenter, long follow-up cohort study

PURPOSE

Status epilepticus (SE) is associated with high morbidity and mortality. This multicenter retrospective cohort study aims to identify the factors associated with the occurrence of SE and the predictors of its recurrence in patients with adult-onset seizures.

METHODS

We retrospectively analyzed data of 1115 patients with seizure onset>18 years, observed from 1983 to 2020 in 7 Italian Centers (median follow-up 2.1 years). Data were collected from the databases of the Centers. Patients with SE were consecutively recruited, and patients without SE history were randomly selected in a 2:1 ratio. To assess determinants of SE, different clinical-demographic variables were evaluated and included in univariate and multivariate logistic regression model.

RESULTS

Three hundred forty-seven patients had a SE history, whereas the remaining 768 patients had either isolated seizures or epilepsy without SE history. The occurrence of SE was independently associated with increasing age at onset of disease (OR 1.02, 95% CI 1.01--1.03, p<0.001), female sex (OR 1.39, 95% CI 1.05--1.83, p=0.02) and known etiology (OR 3.58, 95% CI 2.61--4.93, p<0.001). SE recurred in 21% of patients with adult-onset SE and recurrence was associated with increasing number of anti-seizure medications taken at last follow-up (OR 1.88, 95% CI 1.31--2.71, p<0.001).

CONCLUSIONS

In patients with adult-onset seizures, SE occurrence is associated with known etiologies, advanced age and female sex. Patients with recurrent SE are likely to have a refractory epilepsy, deserving careful treatment to prevent potentially fatal events.

Non-Pharmacological and Non-Surgical Treatment of Refractory Childhood Epilepsy

Nearly 20-40% of patients with epilepsy are likely to have drug resistant epilepsy (DRE). Add-on antiseizure drugs do not produce optimal seizure control in these patients. Among the non-pharmacological options, only resective surgery is curative. However, a large majority of patients are not candidates for resective epilepsy surgery. For these children with DRE, non-pharmacological non-surgery "palliative" options should be considered early than late. These include dietary therapies and neuromodulation. While there are numerous clinical trials supporting the efficacy of dietary therapies (viz ketogenic diet, modified Atkins diet and low glycemic index therapy), the evidence for neuromodulation is still evolving. Neuromodulation techniques include vagal nerve stimulation, deep brain stimulation, and transcranial magnetic stimulation. Each of the options, whether diet or neuromodulation, has its own advantages, disadvantages and adverse events profile. These have to be considered and discussed with the family before deciding the modality being chosen.

The functional connectivity study on the brainstem-cortical/subcortical structures in responders following cervical vagus nerve stimulation

BACKGROUND

Cervical vagus nerve stimulation (VNS) is an effective neuromodulation therapy for patients with drug-resistant epilepsy (DRE). The previous studies reported that VNS may reduce seizures by regulating the functional connectivity (FC) between cortical and subcortical regions. However, no studies on brainstem have been done in responders who achieved ≥50% seizure reduction following VNS.

METHODS

Eight healthy controls and eight patients who became responders after 3 months of operation were enrolled in this study. Resting-state functional MRI (rs-fMRI) was performed, and two sample and paired sample t test were, respectively, used to detect altered FC between brainstem and cortical/subcortical regions between controls and patients, between preoperative and postoperative patients.

RESULTS

In the control group, regions with highest FC to brainstem included bilateral anterior cingulate gyri, left basal ganglia, left insula, left cuneus, right precuneus, and bilateral cerebellum. In preoperative patients, right frontal middle gyrus, bilateral basal ganglia, and right cerebellum were showed highest FC to brainstem. Compared with the controls, preoperative patients exhibited increased FC in bilateral inferior frontal gyri, right temporal cortex, while decreased FC in left insula, left postcentral gyrus, right posterior cingulate gyrus, right precuneus, and left superior parietal gyrus. In postoperative patients, regions with increased FC to brainstem were left insula, left precuneus and left cuneus, and those with decreased FC were right inferior occipital gyrus and right cerebellum.

CONCLUSIONS

Recurrent seizures caused disturbances in brainstem-cortical/subcortical FC, especially in motor executive function related regions and default mode network. VNS could reorganize the altered FC between brainstem and insula, precuneus, and cerebellum in responders.

Genetic generalized and focal epilepsy prevalence in the North American SUDEP Registry

Objective

To assess relative rates and clinical features of patients with genetic generalized epilepsy (GGE), focal epilepsy (FE), and developmental encephalopathic epilepsy (DEE) in the North American SUDEP Registry (NASR).

Methods

We identified all adjudicated definite, definite plus, and probable sudden unexpected death in epilepsy (SUDEP) cases (n = 262) and determined epilepsy type (GGE, FE, or DEE) from medical record review including history, imaging and EEG results, genetics, and next-of-kin interviews.

Results

Of the 262 SUDEP cases, 41 occurred in GGE, 95 in FE, 24 in DEE, and 102 were unclassifiable. GGE cases comprised 26% of NASR cases with an epilepsy syndrome diagnosis. The relative frequency of FE:GGE was slightly lower (2.3:1) than in population cohorts (2.1–6:1). Compared to patients with FE, patients with GGE had similar (1) ages at death and epilepsy onset and rates of (2) terminal and historical antiseizure medication adherence; (3) abnormal cardiac pathology; (4) illicit drug/alcohol use histories; and (5) sleep state when SUDEP occurred.

Conclusions

GGE cases were relatively overrepresented in NASR. Because GGEs are less often treatment-resistant than FE or DEE, seizure type rather than frequency may be critical. Many people with GGE predominantly have generalized tonic-clonic seizures (GTCS) when they have uncontrolled or breakthrough seizures, whereas patients with FE more commonly experience milder seizures. Future mechanistic SUDEP studies should assess primary and focal-to-bilateral GTCS to identify potential differences in postictal autonomic and arousal disorders and to determine the differential role that lifestyle factors have on breakthrough seizures and seizure types in GGE vs FE to effectively target SUDEP mechanisms and prevention.

Antiepileptic and anti-neuroinflammatory effects of red ginseng in an intrahippocampal kainic acid model of temporal lobe epilepsy demonstrated by electroencephalography

Background

Chronic inflammation can lower the seizure threshold and have influence on epileptogenesis. The components of red ginseng (RG) have anti-inflammatory effects. The abundance of peripherally derived immune cells in resected epileptic tissue suggests that the immune system is a potential target for anti-epileptogenic therapies. The present study used continuous electroencephalography (EEG) to evaluate the therapeutic efficacy of RG in intrahippocampal kainic acid (IHKA) animal model of temporal lobe epilepsy.

Methods

Prolonged status epilepticus (SE) was induced in 7-week-old C57BL/6J mice via stereotaxic injection of kainic acid (KA, 150 nL; 1 mg/mL) into the right CA3/dorsal hippocampus. The animals were implanted electrodes and monitored for spontaneous seizures. Following the IHKA injections, one group received treatments of RG (250 mg/kg/day) for 4 weeks (RG group, n=7) while another group received valproic acid (VPA, 30 mg/kg/day) (VPA group, n=7). Laboratory findings and pathological results were assessed at D29 and continuous (24 h/week) EEG monitoring was used to evaluate high-voltage sharp waves on D7, D14, D21, and D28.

Results

At D29, there were no differences between the groups in liver function test but RG group had higher blood urea nitrogen levels. Immunohistochemistry analyses revealed that RG reduced the infiltration of immune cells into the brain and EEG analyses showed that it had anticonvulsant effects.

Conclusion

Repeated treatments with RG after IHKA-induced SE decreased immune cell infiltration into the brain and resulted in a marked decrease in electrographic seizures. RG had anticonvulsant effects that were similar to those of VPA without serious side effects.