Determining when to stop antiepileptic drug treatment

The incidence and predictive factors of secondary epilepsy in patients with supratentorial brain metastases (st-BMs) after stereotactic radiosurgery: A multicenter retrospective study

OBJECTIVE

To evaluate the incidence and the independent risk factors of SRS-related epilepsy in patients with supratentorial brain metastases (st-BMs), providing evidences for prevention or reduction secondary epilepsy after SRS.

METHODS

Patients with st-BMs from four gamma knife centers who developed secondary epilepsy after SRS were retrospectively studied between January 1, 2017 and June 31, 2023. The incidence and clinical characteristics of the patients with secondary epilepsy were analyzed. The predictive role of baseline clinical-demographic variables was evaluated according to univariate and multivariate logistic regression model. The impact of secondary epilepsy on patients' OS was evaluated as well by log-rank test.

RESULTS

11.3 % (126/1120) of the patients with totally 158 st-BMs experienced secondary epilepsy after SRS in median 21 days. 61.9 % (78/126) of the patients experienced simple partial seizures. 91.3 % (115/126) patients achieved good seizure control after received 1-2 kinds of AEDs for median 90 days, while 7.1 % (9/126) of the patients suffered from refractory epilepsy. Patients had higher risk of secondary epilepsy if the tumor located in cortex and/or hippocampus, peri-tumor edema larger than 20.3 cm3 before SRS, had epilepsy history, and failed to receive bevacizumab prior to SRS. There was no difference in the OS of patients who experience secondary epilepsy or not after SRS.

CONCLUSIONS

The incidence of SRS-related secondary epilepsy is 11.3 % in patients with st-BMs in this retrospective study. The risk of secondary epilepsy is higher in patients with st-BM located in cortex and/or hippocampus area, peri-tumor edema larger than 20.3 cm3 before SRS, and epilepsy history. Bevacizumab is suggested prior to SRS therapy, as it could be used for the control of peri-tumor edema and SRS-related damage, hence reduce the risk of secondary epilepsy. However, whether or not patients suffered from secondary epilepsy after SRS does not affect their OS.

Risk factors of recurrence after drug withdrawal in children with epilepsy

This study aimed to evaluate the risk factors for recurrence in pediatric patients with epilepsy following normal antiseizure medication (ASM) treatment and drug withdrawal. We retrospectively analyzed 80 pediatric patients who received treatment at the Qilu Hospital of Shandong University between January 2009 and December 2019 after at least 2 years of seizure-free and normal electroencephalography (EEG) before the regular drug reduction. Patients were followed-up for at least 2 years and divided into the recurrence and nonrecurrence groups based on whether relapse occurred. Clinical information was gathered, and the risk variables for recurrence were statistically analyzed. Post 2 years of drug withdrawal, 19 patients showed relapses. The recurrence rate was 23.75%, and the mean time of recurrence was 11.09 ± 7.57 months, where 7 (36.8%) were women and 12 (63.2%) were men. In all, 41 pediatric patients were followed-up until the 3rd year, of which 2 (4.9%) patients experienced a relapse. Among the remaining 39 patients without relapse, 24 were followed-up until the 4th year, and no recurrence occurred. After being monitored for >4 years, 13 patients experienced no recurrence. The differences in the history of febrile seizures, combined use of ≥2 ASMs, and EEG abnormalities after drug withdrawal between the two groups were statistically significant (p < 0.05). Multivariate binary logistic regression analysis revealed that these factors are independent risk factors for recurrence after drug withdrawal in children with epilepsy: history of febrile seizures (OR = 4.322, 95% CI: 1.262-14.804), combined ASM use (OR = 4.783, 95% CI: 1.409-16.238), and EEG abnormalities after drug withdrawal (OR = 4.688, 95% CI: 1.154-19.050). In summary, our results suggest that the probability of seizure recurrence following drug cessation may be greatly increased by a history of febrile seizures, concomitant use of ≥2 ASMs, and EEG abnormalities after drug cessation. The majority of recurrences occurred in the first 2 years following drug discontinuation, whereas the rate of recurrence was minimal thereafter.

Characteristics, surgical outcomes, and influential factors of epilepsy in Sturge-Weber syndrome

Few studies have reported the clinical presentation, surgical treatment, outcomes and influential factors for patients with epilepsy and Sturge-Weber syndrome. This large-scale retrospective study continuously enrolled 132 patients with Sturge-Weber syndrome and epilepsy from January 2008 to December 2018 at our hospital to analyse their characteristics. Among these patients, 90 underwent epilepsy surgery, and their postoperative 2-year follow-up seizure, cognitive and motor functional outcomes were assessed and analysed. Univariable and multivariable logistic analyses were conducted to explore the influential factors. Among the patients with Sturge-Weber syndrome for whom characteristics were analysed (n = 132), 76.52% of patients had their first epileptic seizures within their first year of life. The risk factors for cognitive decline were seizure history ≥ 2 years [adjusted odds ratio (aOR) = 3.829, 95% confidence interval (CI): 1.810-9.021, P = 0.008)], bilateral leptomeningeal angiomas (aOR = 3.173, 95% CI: 1.970-48.194, P = 0.013), age at onset <1 year (aOR = 2.903, 95% CI: 1.230-6.514, P = 0.013), brain calcification (aOR = 2.375, 95% CI: 1.396-5.201, P = 0.021) and left leptomeningeal angiomas (aOR = 2.228, 95% CI: 1.351-32.571, P = 0.030). Of the patients who underwent epilepsy surgery (n = 90), 44 were subject to focal resection, and 46 underwent hemisphere surgery (19 anatomical hemispherectomies and 27 modified hemispherotomies). A postoperative seizure-free status, favourable cognitive outcomes, and favourable motor outcomes were achieved in 83.33%, 44.44% and 43.33% of surgical patients, respectively. The modified hemispherotomy group had similar surgical outcomes, less intraoperative blood loss and shorter postoperative hospital stays than the anatomical hemispherectomy group. Regarding seizure outcomes, full resection (aOR = 11.115, 95% CI: 1.260-98.067, P = 0.020) and age at surgery < 2 years (aOR = 6.040, 95% CI: 1.444-73.367, P = 0.031) were positive influential factors for focal resection. Age at surgery < 2 years (aOR = 15.053, 95% CI: 1.050-215.899, P = 0.036) and infrequent seizures (aOR = 8.426, 95% CI: 1.086-87.442, P = 0.042; monthly versus weekly) were positive influential factors for hemisphere surgery. In conclusion, epilepsy surgery resulted in a good postoperative seizure-free rate and favourable cognitive and motor functional outcomes and showed acceptable safety for patients with epilepsy and Sturge-Weber syndrome. Modified hemispherotomy is a less invasive and safer type of hemisphere surgery than traditional anatomic hemispherectomy with similar surgical outcomes. Early surgery may be helpful to achieve better seizure outcomes and cognitive protection, while the risk of surgery for young children should also be considered.

Biosensors technology for anti-epileptic drugs

A broad group of antiepileptic drugs (AEDs) often controls the frequency of seizures. Given the variability of pharmacokinetics, narrow target range, and the difficulty of identifying signs of toxicity from laboratory responses, therapeutic monitoring of AEDs plays a vital role in optimizing drug administration. Nanomaterials, especially biosensor-based methods, can facilitate the analysis of these agents with unique advantages such as rapid analysis, sensitivity, selectivity, and low cost. This review describes recent advances in biosensors developed to analyze AEDs. First, we described common electrochemical measurement techniques and types of deposited electrode substrates. Additionally, various chemical and biological modifiers to improve the sensitivity and selectivity of the sensor have been categorized and briefly described. Finally, the prospects for developing an electrochemical platform for quantifying AEDs are presented.

Electrophysiological and behavioral properties of 4-aminopyridine-induced epileptic activity in mice

4-aminopyridine (4-AP) is a widely used drug that induces seizure activity in rodents, especially in rats, although there is no consensus in the literature on the dose to be used in mice. The aim of the present study was to investigate the effect of the intraperitoneal administration of 4-AP in two doses (4 and 10 mg/kg) in vivo. EEG, movement, and video recordings were made simultaneously in male B6 mice to specify the details of the seizures and to determine whether there is a suitable non-lethal dose for seizure induction and for further molecular studies. Seizure behavior in mice differs from that seen in rats, with no characteristic stages of epileptic seizures, but with spiking and seizure activity. Seizure activity, although produced at both doses without being lethal, induced different changes of the EEG pattern. Smaller dose induced a lower amplitude seizure activity, decreased spiking activity and later onset of seizures, while higher dose induced a much more intense brain seizure activity and severe trembling. It is concluded that the intraperitoneal administration of 4-AP at a dose of 10 mg/kg induces explicit seizure activity in mice which is repeatable and can be suitable for further molecular research.

Microstructural features of the cerebral cortex: Implications for predicting epilepsy relapse after drug withdrawal

A considerable portion of patients with well-controlled seizures and visually normal brain structures experience seizure recurrence after anti-seizure medication is withdrawn. Microstructural abnormalities of the cortex may play an essential role in epilepsy relapse. Patients with idiopathic/cryptogenic epilepsy were registered. At the follow-up endpoint, 18 patients with relapse (PR+ group), 20 patients without relapse (PR- group), and 30 healthy controls were included. High-resolution T1-weighted images were obtained at the time of drug withdrawal. Microstructural features including cortical thickness, surface area, cortical volume and mean curvature in 68 cortical areas were calculated. A general linear model was applied to investigate intergroup differences, and then post hoc analysis was performed. Additionally, factor analysis was conducted to extract components from imaging measures showing a difference between PR- and PR+ groups, and independent associations between components and epilepsy relapse were assessed using a logistic regression model. Cortical thickness of the left paracentral lobule, left temporal pole and right superior frontal gyrus; surface area of the bilateral lingual gyrus and bilateral pericalcarine cortex; and cortical volume of the bilateral pericalcarine cortex had significant intergroup differences (false discovery rate correction, P < 0.05). All measures, except for cortical thickness of the left temporal pole, showed differences between PR- and PR+ groups. Two dominant components were extracted from these measures, and both were independently associated with epilepsy relapse. In conclusion, epilepsy patients with relapse presented distinct microstructural features of cortex at the time of drug withdrawal, which may serve as a potential biomarker for predicting seizure recurrence.

Epilepsy Research in Mali: A Pilot Pharmacokinetics Study on First-Line Antiepileptic Drug Treatment

Background and Purpose

The indication and benefit of plasma level of antiepileptic (AEDs) has been debating in the monitoring of people living with epilepsy and the epilepsy treatment gap has largely been documented in developed countries. This study was aimed to highlight the epilepsy treatment gap between rural and urban Mali.

Methods

We conducted a pilot study on AEDs treatment from September 2016 to May 2019. For 6 months, 120 children and young adults living with epilepsy (rural site, 90; urban site, 30) received phenobarbital, valproic acid and/or carbamazepine. At our rural study site, we determined the AED plasma levels, monitored the frequency, severity and the duration of seizure, and administered monthly the McGill quality of life questionnaire. At our urban study site, each patient underwent an electroencephalogram and brain computed tomography scan without close monitoring.

Results

At the rural study site, patients were mostly on monotherapy; AED levels at 1 month (M1) (n=90) and at 3 months (M3) (n=27) after inclusion were normal in 50% at M1 versus 55.6% at M3, low in 42.2% at M1 versus 33.3% at M3 and high in 7.8% at M1 versus 11.1% at M3. AED levels at M1 and at M3 were significantly different p<0.0001. By M3, seizures (n=90) were <1/month in 26.7%, and lasted less than 1 minute in 16.7%. After a yearlong follow up, all 90 patients reported a good or excellent quality of life. At our urban study site, patients (n=30) were on carbamazepine and valproid acid in 66.67% and monotherapy (carbamazepine) in 33.33%. By November 2018, only six out 30 patients (on bi-therapy) were still taking their medications.

Conclusions

Epilepsy diagnostic and treatment are a real concern in Mali. Our data showed appropriate AED treatment with close follow up resulted in a better quality of life of patients in rural Mali. We will promote the approach of personalized medicine in AED treatment in Mali.

Patients' attitude toward AED withdrawal: A survey among individuals who had been seizure-free for over 2 years

OBJECTIVE

The study aimed to evaluate the attitudes of seizure-free patients toward the antiepileptic drug (AED) withdrawal and to highlight the factors that affect their perspectives.

METHODS

The study participants were recruited among the individuals attending the epilepsy outpatient clinic of a university hospital in Skopje between January 2018 and April 2019. Patients with epilepsy who had been seizure-free for at least 2 years on stable monotherapy were included.

RESULTS

Among the 90 participants, 43 were female, and the mean age was 36.3 years. The mean duration of active epilepsy before remission was 7.9 years, and the length of the seizure-free period at the time of evaluation was 2-20 years. Forty-four percent of participants aimed to taper their antiseizure medications because of concerns about the potential long-term side effects and teratogenicity, the burden of taking medication daily, stigma, as well as the impression of no longer having a chronic disease after withdrawal. The majority of them preferred slow versus rapid withdrawal. On the other side, 55% of patients choose to continue AED treatment, mainly feeling well-adjusted to it and being concern about possible seizure recurrence after withdrawal and subsequent loss of driving license or even their jobs. Previous unsuccessful attempts to discontinue AED together with previously uncontrolled seizures were additional motives against withdrawal. The patients' views toward stopping or withholding AED were significantly associated with their gender and marital status (male patients as well as single ones favored medication withdrawal). Patients' age to some extent, though not significantly, affected their viewpoints (younger participants tended to question the further necessity of AEDs and were more concerned about the potential adverse consequences). No other demographic or epilepsy-related data considerably predisposed the decisions.

CONCLUSIONS

More than half of the patients with epilepsy preferred to continue their AED after 2 years of seizure freedom. Male gender, being single, and somewhat younger age were associated preferences to withdraw AED.