Directional deep brain stimulation of the centromedian thalamic nucleus reduces DBS-induced ataxia and dysarthria in Lennox-Gastaut Syndrome: A single case study.

Background: We present a case of a 46-year-old man with Lennox-Gastaut syndrome and drug-resistant epilepsy. An adjunctive neurostimulation therapy strategy was implemented involving bilateral deep brain stimulation (DBS) of the centromedian thalamic nucleus (CMT). Methods: Robotically assisted implantation of bilateral DBS directional lead system with 8 contacts in the CMT was performed. The clinical course was assessed in repeated in-patient follow-ups. Results: Initial DBS stimulation resulted in progressive ataxia and dysarthria significantly beyond the level seen before surgery. Deactivation of DBS coincided with improvement of dysarthria. A DBS stimulation paradigm with reduction of lateral and superior stimulation resulted in improvement and eventually complete resolution of the stimulation side effect. Discussion: This case suggests that stimulation-induced dysarthria in DBS can be improved by targeted reduction of lateral and/or superior thalamic stimulation. When dysarthria and ataxia occur during DBS, directed stimulation to medial thalamic structures and more inferior electrode contacts offers a promising strategy to reduce side effects while maintaining positive effects.

Developmental and epileptic encephalopathies after successful treatment of pediatric ALL: A case series and review of literature.

Successful treatment of acute lymphoblastic leukemia (ALL) requires multiagent chemotherapy regimens and central nervous system prophylaxis, including intrathecal methotrexate. Although acute symptomatic seizures can occur during ALL treatment, epilepsy is less common. Furthermore, drug resistant epilepsy (DRE) is rare, presenting with two phenotypes: focal epilepsy, such as temporal lobe, or epileptic encephalopathies (EE), such as Lennox-Gastaut syndrome (LGS). For ALL survivors, the development of DRE has significant impact on morbidity, mortality, and quality of life. We describe four patients with ALL remission, who developed EEs, of which 3 had LGS. Mean age at ALL diagnosis was 1.9 years; range 1.1-2.5 years. All, but one, had normal development prior to ALL. No patient had CNS leukemic involvement. All patients received CNS prophylaxis with intrathecal methotrexate, without cranial radiotherapy. Three had symptomatic methotrexate neurotoxicity during treatment. The mean age at first seizure was 5.6 years; range 3.9-7.5 years, with a mean latency of 3.7 years from ALL diagnosis. All patients developed drug resistant EEs, moderate intellectual disability, and neuropsychiatric co-morbidities. Two patients had a minimal response to corpus callosotomy (CC), and one did not respond the ketogenic diet. Successful treatment of childhood ALL is rarely associated with the development of DRE and EEs. Young age at ALL diagnosis (<3 years) may be a predisposing factor. Palliative treatments, including ketogenic diet and CC have limited benefit in these patients. Individual genetic susceptibility to MTX toxicity is likely related to epileptogenesis, and further research is required for epilepsy biomarkers.

A Complex Presentation: Psychosis in a Patient Diagnosed With Lennox-Gastaut Syndrome.

Lennox-Gastaut syndrome (LGS) is a form of severe childhood epilepsy, with most children experiencing seizures before reaching the age of eight. Typically, patients have multiple types of seizures, making an accurate diagnosis challenging. While it can be secondary to other causes, often, it is idiopathic. Over time, children develop cognitive impairment, leading to intellectual disability. The mainstay of treatment and management is seizure control. However, management remains challenging due to the complexity of the syndrome, as it is associated with multiple seizure types, intellectual deterioration, and other psychiatric comorbidities. We present the case of a 19-year-old male diagnosed with LGS and treated with various available therapies, who demonstrated multiple breakthrough seizures, significant neurocognitive disabilities, and behavior challenges. Additionally, the patient displayed psychotic features of auditory hallucinations, aggression, and attempts at self-mutilation, a rare clinical presentation in LGS.

Endoscopic transventricular "inside-out" corpus callosotomy: illustrative case.

BACKGROUND: Tonic and atonic "drop attack" seizures are a classic and morbid semiology in Lennox-Gastaut syndrome, resulting in frequent injuries and emergency room visits, in addition to neurocognitive sequelae. Recent years have seen a growing interest in less invasive techniques for performing the classic surgical treatment for drop attacks in Lennox-Gastaut syndrome, that is, corpus callosotomy. OBSERVATIONS: A 5-year-old boy with Lennox-Gastaut syndrome presented for surgical evaluation. He experienced up to 20 daily tonic seizures despite multiple antiseizure medications. Preoperative imaging revealed highly abnormal anatomy with severe ventriculomegaly and thinning of the cortex and corpus callosum. Open microsurgery or an interhemispheric bimanual endoscopic approach to corpus callosotomy posed a risk for ventricular collapse and subdural hematoma, and the corpus callosum was too thin for laser ablation. A fully endoscopic transventricular "inside-out" complete corpus callosotomy was performed through a 7-mm burr hole via a single working channel without intraoperative complications. The patient continues to experience daily seizures but with a reduced frequency and intensity and a family-reported increased quality of life. LESSONS: In cases of drug-resistant tonic and atonic seizures associated with ventriculomegaly, a fully endoscopic transventricular complete corpus callosotomy can be performed safely, potentially limiting the risk of ventricular collapse and subdural bleeding. https://thejns.org/doi/10.3171/CASE24160.

Successful use of Fenfluramine in super-refractory status epilepticus in a patient with tuberous sclerosis complex and Lennox-Gastaut syndrome.

A 24-year-old female patient with pre-existing refractory epilepsy caused by tuberous sclerosis (TSC) and electroclinical features of Lennox-Gastaut syndrome (LGS) was referred to our hospital from an external clinic. Upon arrival, she presented with super-refractory status epilepticus (SRSE) since anaesthetics had already been used in the referring clinic. Despite various changes in ASM-treatment and continuous administration of anaesthetics for more than two weeks, SRSE could not be terminated. On treatment day 24, we started Fenfluramin (FFA) which was soon titrated to a dose of 0,7 mg/kg/day. A few days after beginning the treatment with FFA, EEG and clinical situation improved dramatically. The following 6 weeks of treatment went without reported seizures. This case illustrates the successful use of FFA in SRSE in TSC and LGS and, to the best of our knowledge, represents the first report of FFA in this clinical context.

Efficacy and Safety of Vagus Nerve Stimulation in Lennox-Gastaut Syndrome: A Scoping Review.

Lennox-Gastaut syndrome (LGS) is a severe developmental and epileptic encephalopathy characterized by drug-resistant seizures, cognitive impairments, and abnormal electroencephalographic patterns. Vagus nerve stimulation (VNS) is a widely used neuromodulation therapy for LGS, but its effects on seizure outcomes, different seizure types, non-seizure outcomes, and adverse events in this population have not been comprehensively reviewed. To conduct a scoping review on the use of VNS in LGS, a literature search was performed in PubMed, OVID, Web of Science, and Embase from inception to 9 June 2024, using relevant keywords and without restrictions on study design. The search yielded forty eligible studies (twenty-four retrospective cohorts, fourteen prospective cohorts, and two registry analyses) comprising 1400 LGS patients treated with VNS. No randomized controlled trials were identified. Across studies, the median seizure reduction ranged from 20.6% to 65%, with 0% to 100% of patients achieving a ≥50% seizure reduction. No consistent preoperative biomarker of VNS responsiveness was identified in LGS. Although inconsistent among different studies, tonic, atonic, and tonic-clonic seizures responded best, while focal seizures responded worst. Improvements in seizure severity, alertness, and quality of life were reported in some studies, but cognitive and adaptive functioning generally remained unchanged. Adverse events were mostly mild and transient, including hoarseness, cough, and paresthesia. Device-related complications and infections were uncommon. In conclusion, further research is needed to better understand VNS's position in the evolving LGS treatment landscape and its cost effectiveness.

Comprehensive scoping review of fenfluramine's role in managing generalized tonic-clonic seizures in developmental and epileptic encephalopathies.

Developmental and epileptic encephalopathies (DEEs) are characterized by pharmacoresistant seizures and developmental delay. Patients with DEEs experience multiple seizure types, including tonic-clonic seizures (TCS) that can be generalized tonic-clonic (GTCS) or focal evolving to bilateral tonic-clonic (FBTCS). Fenfluramine (FFA) has demonstrated efficacy in reduction of TCS in patients with Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and other DEEs. Using the PRISMA-ScR (Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Review) guidelines, we performed a scoping review to describe changes in TCS in patients treated with FFA. A comprehensive search of five literature databases was conducted up to February 14, 2023. Studies were included if they reported change in GTCS or TCS (but not FBTCS) after treatment with FFA in patients with DEEs. Duplicate patients and studies with unclear efficacy data were excluded. Fourteen of 422 studies met the eligibility criteria. Data extracted and evaluated by expert clinicians identified 421 unique patients with DS (in nine studies), CDKL5 deficiency disorder, SCN8A-related disorder, LGS, SCN1B-related disorder, and other DEEs. The median percent reduction in GTCS or TCS from baseline was available in 10 studies (n = 328) and ranged from 47.2% to 100%. Following FFA treatment, 10 studies (n = 144) reported ≥50% reduction in GTCS or TCS from baseline in 72% of patients; in nine of those (n = 112), 54% and 29% of patients achieved ≥75% and 100% reduction in GTCS or TCS from baseline, respectively. Overall, this analysis highlighted improvements in GTCS or TCS frequency when patients were treated with FFA regardless of the DEE evaluated. Future studies may confirm the impact of FFA on TCS reduction and on decreased premature mortality risk (including sudden unexpected death in epilepsy), improvement in comorbidities and everyday executive function, decreased health care costs, and improvement in quality of life.

The emotional burden of caring for patients with Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex-associated epilepsy: A qualitative study in Japan.

INTRODUCTION: Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare, childhood-onset conditions associated with severe, treatment-resistant epilepsy and developmental issues, including motor and cognitive impairment. Tuberous sclerosis complex (TSC) is a rare genetic disease commonly associated with epilepsy and other neuropsychiatric disorders. This cross-sectional, interview-based study examined the qualitative impact of caring for patients with LGS, DS, and TSC-associated epilepsy on caregivers in Japan, from the perspective of both caregivers and physicians. METHODS: The survey included a pre-interview worksheet to describe caregivers' emotional journeys, followed by a ≤ 60-minute one-on-one interview. Eligible participants were Japanese caregivers of patients with LGS, DS, or TSC treated for epilepsy symptoms, and Japan-residing pediatricians or neurologists treating ≥ 3 patients with LGS, DS, and/or TSC. Interview question responses were subjected to content analysis to identify the most common response tendencies and themes. RESULTS: Twenty-six caregivers responded (mean [standard deviation (SD)] age, 45.9 [9.5] years; age range 29-68; 92 % female), caring for patients with LGS (n = 5), DS (n = 10), and TSC (n = 11); patient mean (SD) age, 13.6 (10.0) years; age range 2-44; 27 % adults; 50 % female. Nineteen physicians, treating patients with LGS (n = 9), DS (n = 7), and TSC (n = 10), participated. Caregivers and physicians generally aligned on the factors affecting caregivers' emotional states / quality of life (QoL). The most frequently reported caregiver emotions at the time of diagnosis were shock and discouragement, anxiety for the future, and relief at receiving a diagnosis. Negative emotions throughout disease progression up until the time of survey were mainly caused by worsening of seizures, burden of constant caregiving / lack of free time, and patient's developmental issues. Positive emotions were linked to effective treatment / reduced seizures; more free time owing to the use of facilities, services, or other caregiving support; and developmental progress. Physicians acknowledged that caregivers required consultation services to support their emotional needs. In terms of unmet needs, caregiver and physician responses were aligned on the insufficient availability of services/facilities, the lack of effective treatments, and the uncertainties of adult patient care. CONCLUSIONS: Caregivers of patients with LGS, DS, or TSC-associated epilepsy in Japan reported a high degree of emotional burden related to frequent seizures, developmental issues, and constant caregiving. The burden of suboptimal treatment effectiveness, limited access to support services, and uncertainties in long-term care emphasize important unmet treatment needs.

A systematic review of electroencephalographic findings in Lennox-Gastaut syndrome.

Lennox-Gastaut syndrome (LGS) is a severe form of childhood onset epileptic encephalopathy characterized by multiple drug-resistant seizures, cognitive impairment, and diffuse slow spike and wave (SSW), and generalized paroxysmal fast activity (GPFA) on electroencephalogram (EEG). Systematic review following the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) guidelines was done to investigate EEG findings in LGS. PubMed and MEDLINE were systematically searched for English-language studies published until15th may 2023. Original articles and research with patients between age group 1-30 years, and studies with description of EEG findings were included. Search identified 20 studies with 1167 patients. In this analysis 62.6 % of patients were male. The median age was 9.6 years. Etiology was structural abnormality in 42.6 %, genetic in 8.7 % but was unknown in 48.7%. Tonic seizures (74.5 %) were most frequent followed by atypical absences (44.3 %), myoclonic (39.2 %), generalized (38.5 %), atonic (34.8 %), epileptic spasm (15.9 %), focal (11.4 %) and non-convulsive status epilepticus (7.0 %). Out of 20 studies, only 15 studies mentioned GPFA in 46.6 % patients and SSW in 91.7 % patients. Unilateral and focal discharges were more common in patients with unilateral structural abnormalities. Seizure discharges on EEG longer than 10 second duration correlated with seizure diary counts. Combination of atonic, tonic, and atypical absence seizures correlated with SSW, and myoclonic seizures correlated with GPFA. EEG helps in diagnosis and prognosis of LGS. SSW is present in almost all EEG, and GPFA in 46.6 % patients. Longer duration of SSW discharges and disorganized background are associated with poor outcome.

Clinical features and underlying etiology of children with Lennox-Gastaut syndrome.

OBJECTIVE: Lennox-Gastaut Syndrome (LGS) is characterized by the presence of multiple seizure types and encompasses a heterogenous group of etiologies. The aim of our study was to evaluate the etiological profile of LGS and investigate seizure outcomes based on different clinical variables. METHODS: The clinical features, neuroimaging findings, genetic testing and other testing results of LGS patients were systematically reviewed. The identifiable etiology was categorized as either acquired or nonacquired. Univariate and multivariate regression analyses were performed to explore the association between clinical variables and seizure outcome at the last follow-up. RESULTS: We enrolled 156 patients diagnosed with LGS, of whom 66% were male. The mean age of patients was 34.2 months and the median follow-up duration was 29.5 months (interquartile range = 14-56.25 months). The initial seizure type was epileptic spasm in 61 patients, among which 33 of them met the criteria for infantile epileptic spasm syndrome. All patients underwent neuroimaging test, with 25% falling into the acquired structural category. Etiology could be identified in 84 individuals, including pathogenetic variants found in 34 out of 117 patients with nonacquired etiology. CHD2 mutations were most frequently observed among these pathogenetic variants. At the last follow-up, favorable outcomes were observed in 27 patients. The identification of etiology emerged as a significant determinant influencing LGS outcome; specifically, patients with unknown etiology had a higher likelihood of experiencing favorable outcomes compared to those with known cause (p = 0.041). Early onset age and longer epilepsy duration significantly increased the odds of an unfavorable outcome (p = 0.006 and 0.024). SIGNIFICANCE: We present novel data on the clinical and etiological spectrum of LGS, with determined etiology observed in over half of the patients. Epileptic spasms were found to be more prevalent than tonic seizures as seizure onset types in LGS. The presence of a known etiology, earlier age at onset, and longer duration of epilepsy were associated with a poorer long-term epileptological outcome.

Practical considerations for the use of fenfluramine to manage patients with Dravet syndrome or Lennox-Gastaut syndrome in clinical practice.

Fenfluramine (FFA), an antiseizure medication (ASM) with serotonergic and sigma-1 receptor activity, is used to manage patients with developmental and epileptic encephalopathies (DEEs). It is approved in the US for treating seizures associated with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) in patients ≥2 years old and as add-on therapy for seizures associated with DS and LGS in the EU, UK, and Japan in similarly aged patients. Consensus guidelines for treatment of DS have recommended FFA to be an early-line ASM, and it has also shown efficacy in managing seizures associated with LGS. DS and LGS are DEEs associated with a range of seizure types, developmental impairments, and multiple comorbidities. Here we provide case vignettes describing 4 patients (3 DS and 1 LGS) aged 4-29 years old in whom up to 14 ASMs had previously failed, to illustrate real-world practice issues encountered by neurologists. This review provides guidance on the use of FFA in the context of ASM polytherapy and drug-drug interactions (DDIs), behavioral issues, dose titration, and adverse events. Along with data from the clinical trial program, these case vignettes emphasize the low risk of DDIs, a generally well-tolerated safety profile, and other seizure and nonseizure benefits (eg, improved cognition and sleep) associated with the use of FFA in DS or LGS. PLAIN LANGUAGE SUMMARY: Fenfluramine is used to treat seizures in individuals with Dravet syndrome and Lennox-Gastaut syndrome, but there are a range of issues that clinicians may face when treating patients. This review highlights four patients from the authors' everyday clinical work and offers guidance and practical considerations by neurologists with expertise in managing these complex conditions related to drug interactions, dosing, and side effects associated with fenfluramine.

Efficacy of enteral feeding by gastrostomy tube placement in patients with Lennox-Gastaut syndrome on body weight and days of hospitalization: A retrospective case series.

BACKGROUND: Lennox-Gastaut syndrome (LGS) is a severe form of drug-resistant epilepsy that begins during childhood and frequently leads to significant neurological impairments. Patients with LGS are likely to receive improper oral nutrition because of issues such as dysphagia and aspiration risk, potentially resulting in long-term tube feeding and eventual gastrostomy tube placement. Therefore, we investigated the effects of gastrostomy tube placement on nutrition outcomes and frequency of hospitalization in LGS. METHODS: We retrospectively examined 67 patients diagnosed with LGS who had undergone gastrostomy tube placement between January 2005 and August 2022. Comprehensive clinical data and complications arising from the procedure were collected. Patients' nutrition condition and frequency of hospitalizations were analyzed before and after gastrostomy tube placement. RESULTS: Gastrostomy tube placement was performed for the following reasons: high risk of aspiration (50 out of 67, 74.6%), dysphagia (13 out of 67, 25.4%), persistent nasogastric tube feeding (2 out of 67, 3.0%), and severe malnutrition (2 out of 67, 3.0%). After the procedure, z scores for weight-for-age improved significantly, shifting from -3.35 ± 3.57 to -2.54 ± 2.70 over a 2-year interval (P < 0.001). Additionally, the total days of hospitalization and days of hospitalization due to respiratory symptoms reduced significantly from 41.94 ± 51.76 to 15.27 ± 26.68 (P < 0.001) and from 23.75 ± 36.92 to 10.52 ± 22.98 (P = 0.009), respectively. Among the patients, 50 (74.6%) experienced complications resulting from gastrostomy, with a relatively small proportion of major complications (11 out of 67, 16.4%) and no mortality. CONCLUSION: Gastrostomy tube placement is a relatively safe procedure with favorable effects on nutrition status and hospitalization rates in patients with LGS.

Have epilepsy outcomes changed for children with tuberous sclerosis complex in Queensland, Australia?

OBJECTIVE: Historically, epilepsy has been the most frequently presenting feature of tuberous sclerosis complex (TSC). Advances in TSC health care have occurred over the past decade; thus, we studied whether TSC epilepsy outcomes have changed. METHOD: A retrospective chart review was undertaken for all children with TSC in Queensland, Australia. Epilepsy outcome and TSC diagnosis data were extracted, and data were compared between children born before 2012 with those born in or after 2012. RESULTS: In this retrospective cohort, TSC diagnosis in children born in or after 2012 is now predominantly antenatal (51%, p < .05). Most patients with epilepsy are now known to have TSC before they develop epilepsy. Despite earlier TSC diagnosis, the frequency of epilepsy (85%) has not changed (p = .92), but diagnosis trends toward an earlier age (median = 3 months for patients born in or after 2012 vs. 5.5 months for those born before 2012, p = .23). Most (95%) patients had focal seizures as their initial clinical seizure type; it was rare (5%) for epileptic spasms (ES) to be the initial seizure type. The frequency of ES was lower in patients born in or after 2012 (36% vs. 50%, p = .27). Infantile (<24 months) onset ES was not associated with worse epilepsy outcome. Late onset ES was seen in 14%, and these patients had a lower rate of epilepsy remission. Lennox-Gastaut syndrome was seen in 7%. Febrile/illness-related status epilepticus occurred in 12% of patients, between 1 and 4 years of age. Despite many (78%) patients having multiple daily seizures at maximal seizure frequency, and 74% meeting criteria for treatment-refractory epilepsy, most patients achieved epilepsy remission (66%), either with epilepsy surgery (47%) or with age (53%). At the time of inclusion in this study, only 21% of patients had uncontrolled frequent (daily to 3 monthly) seizures and 14% had uncontrolled infrequent (3 monthly to <2 yearly) seizures. SIGNIFICANCE: This study provides updated information that informs the counseling of parents of newly diagnosed pediatric TSC patients.

Effectiveness of Highly Purified Cannabidiol in Refractory and Super-Refractory Status Epilepticus: A Case Series.

INTRODUCTION: Refractory and super-refractory status epilepticus are medical emergencies that must be promptly treated in consideration of their high mortality and morbidity rate. Nevertheless, the available evidence of effective treatment of these conditions is scarce. Among novel antiseizure medications (ASMs), highly purified cannabidiol (hpCBD) has shown noteworthy efficacy in reducing seizures in Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and Tuberous Sclerosis Complex (TSC). CASE PRESENTATION: Here, we present two cases of effective use of hpCBD in both refractory and super- refractory status epilepticus. The administration of the nasogastric tube permitted the resolution of status epilepticus without adverse events. At 6-month follow-up, both patients were on hpCBD treatment, which continued to be efficacious for treating seizures. CONCLUSION: According to our experience, hpCBD should be taken into consideration as an add-on therapy of RSE and SRSE while also considering the possibility of maintaining this treatment during the follow-up of patients. However, more studies and real-world experiences are needed to better understand its effectiveness in this setting and the interaction with other ASMs.

The Association Between Serum Levels of Glial Biomarkers, Clinical Severity and Electro-encephalography Features in Idiopathic West and Lennox-Gastaut Syndromes.

Introduction: Although the contribution of enhanced glial activity in seizure induction is increasingly recognized, the role of glia-induced neuroinflammation in the physiopathology of epileptic encephalopathy (EE) has been scarcely investigated. Methods: To delineate the contribution of glial activity in EE, we measured levels of glia-derived mediators with previously described biomarker value, including glial fibrillary acidic protein (GFAP), high mobility group box 1 (HMGB1), chitinase-3-like protein 1 (CHI3L1), soluble CD163 (sCD163) and triggering receptor expressed on myeloid cells 2 (TREM2) by ELISA in sera of patients with idiopathic West syndrome (WS, n=18), idiopathic Lennox-Gastaut syndrome (LGS, n=13) and healthy controls (n=31). Results: Patients with EE showed significantly higher CHI3L1 levels compared to healthy controls. Levels of HMGB1, CHI3L1, sCD163 and TREM2 were higher in LGS patients than WS patients and/or healthy controls. One or more of the investigated mediators were associated with treatment responsiveness, disease severity and presence of pathological features on electroencephalography (EEG). Conclusions: To our knowledge, our findings provide the initial patient-based evidence that astrocyte- and microglia-mediated neuroinflammation might be involved in the pathogenesis of LGS and WS. Moreover, glial mediators may serve as prognostic biomarkers in patients with idiopathic EE.

Is adjunctive Cannabidiol effective in controlling seizures for adult patients with Lennox-Gastaut Syndrome? - A single centre long term follow up study.

Epileptic encephalopathies are a disabling and life-limiting cause of childhood-onset epilepsy. Lennox Gastaut syndrome (LGS) is a characteristic example. In spite of the development of multiple medical and surgical therapies, many patients with these conditions remain treatment refractory Cannabidiol was licenced by The National Institute for Health and Care Excellence (NICE) in December 2019 for the adjunctive treatment of seizures associated with Lennox Gastaut syndrome [TA 615]. As the largest complex epilepsy centre in the Midlands, we describe our findings from a single centre retrospective study in 50 adults (aged 16 and over) with LGS- associated epilepsy. Our outcome measure was the efficacy of Cannabidiol on seizures of differing types over a 6-24-month period. Patients were treated with adjunctive Cannabidiol (with Clobazam, as per NICE recommendations). Each patient's usual anti-seizure medications (ASMs) were continued. Patients with a Vagal Nerve Stimulator (VNS) in situ remained on this treatment. Gradual titration of Cannabidiol from 1 mg/kg/day up to 10 mg/ kg/ day reduced the frequency of both focal and generalised seizures with ≥ 50 % seizure reduction in 76 % of the cohort. No patients became seizure free. Cannabidiol was well tolerated; 94 % of the cohort remained on the drug at last follow up.

Targeting thalamocortical circuits for closed-loop stimulation in Lennox-Gastaut syndrome.

This paper outlines the therapeutic rationale and neurosurgical targeting technique for bilateral, closed-loop, thalamocortical stimulation in Lennox-Gastaut syndrome, a severe form of childhood-onset epilepsy. Thalamic stimulation can be an effective treatment for Lennox-Gastaut syndrome, but complete seizure control is rarely achieved. Outcomes may be improved by stimulating areas beyond the thalamus, including cortex, but the optimal targets are unknown. We aimed to identify a cortical target by synthesizing prior neuroimaging studies, and to use this knowledge to advance a dual thalamic (centromedian) and cortical (frontal) approach for closed-loop stimulation. Multi-modal brain network maps from three group-level studies of Lennox-Gastaut syndrome were averaged to define the area of peak overlap: simultaneous EEG-functional MRI of generalized paroxysmal fast activity, [18F]fluorodeoxyglucose PET of cortical hypometabolism and diffusion MRI structural connectivity associated with clinical efficacy in a previous trial of thalamic deep brain stimulation. The resulting 'hotspot' was used as a seed in a normative functional MRI connectivity analysis to identify connected networks. Intracranial electrophysiology was reviewed in the first two trial patients undergoing bilateral implantations guided by this hotspot. Simultaneous recordings from cortex and thalamus were analysed for presence and synchrony of epileptiform activity. The peak overlap was in bilateral premotor cortex/caudal middle frontal gyrus. Functional connectivity of this hotspot revealed a distributed network of frontoparietal cortex resembling the diffuse abnormalities seen on EEG-functional MRI and PET. Intracranial electrophysiology showed characteristic epileptiform activity of Lennox-Gastaut syndrome in both the cortical hotspot and thalamus; most detected events occurred first in the cortex before appearing in the thalamus. Premotor frontal cortex shows peak involvement in Lennox-Gastaut syndrome and functional connectivity of this region resembles the wider epileptic brain network. Thus, it may be an optimal target for a range of neuromodulation therapies, including thalamocortical stimulation and emerging non-invasive treatments like focused ultrasound or transcranial magnetic stimulation. Compared to thalamus-only approaches, the addition of this cortical target may allow more rapid detections of seizures, more diverse stimulation paradigms and broader modulation of the epileptic network. A prospective, multi-centre trial of closed-loop thalamocortical stimulation for Lennox-Gastaut syndrome is currently underway.

Functional brain network analysis using electroencephalography in late-onset Lennox-Gastaut syndrome.

OBJECTIVE: We aimed to explore the clinical characteristics and functional network properties of patients with late-onset Lennox-Gastaut syndrome (LGS). METHODS: Late-onset LGS was defined by the appearance of LGS features after 8 years of age. We reviewed the medical charts of 9 patients with late-onset LGS, and performed electroencephalography connectivity analysis using graph theory. We assessed the clustering coefficient (CC) and characteristic path length (CPL), which are common basic measures of functional networks that represent local segregation and global integration. The characteristics and brain parameters of late-onset LGS were compared with a typical age-onset LGS group. RESULTS: Late onset LGS subjects were older than typical age onset LGS at the time of testing, but otherwise there were no significant differences in clinical characteristics. The late-onset group showed higher median CC values in the alpha (p = 0.045) and beta (p < 0.001) bands over brain regions implicated in cognitive processing. There were no significant differences in CPL between the LGS groups. CONCLUSIONS: Higher clustering coefficient values, in alpha/beta bands over brain regions implicated in cognitive processing, are consistent with increased cognitive network segregation in late onset LGS compared to typical age-onset LGS. Given network segregation is a normal aspect of brain maturation, these results imply that this process is less disturbed when the LGS process begins later in childhood.

Real-world use of the updated refractory epilepsy screening tool for Lennox-Gastaut syndrome.

OBJECTIVE: To evaluate the Refractory Epilepsy Screening Tool for Lennox-Gastaut Syndrome (REST-LGS) for real-world identification of LGS in adults and to develop a scoring system for the tool. METHODS: A retrospective chart review of adults with drug resistant epilepsy (DRE) and intellectual development disorder (IDD) was conducted by 2 primary care providers blinded to diagnosis. The REST-LGS was designed via the Modified Delphi Consensus and was previously validated. This tool consists of 8 criteria (4 major, 4 minor) considered indicative of LGS. To account for missing data in the earlier validation study and to evaluate applicability in a real-world setting, the REST-LGS was refined to include a scoring system in which major criteria were more heavily weighted than minor criteria, producing categories of "likely" (>11 points), "possible" (8-11 points), and "unlikely" (<8 points) LGS. Statistical analyses were descriptive. RESULTS: Of the 100 patients included in the analysis, data for slow spike-waves in electroencephalography and seizure onset age - both major REST-LGS criteria - were missing for 46% and 42% of patients, respectively. The majority of patients met 4 of the 8 REST-LGS criteria (cognitive impairment since childhood, 71%; persistent seizures despite a trial of ≥2 antiseizure medications, 65%; seizure onset before the age of 12 years, 57%; ≥2 seizure types, 56%). All 4 major criteria were met in 22 patients (22%). The percentages of patients considered "likely," "possible," or "unlikely" to have LGS were 26%, 30%, and 44%, respectively. Of the 74 patients without a previous LGS diagnosis, 42 (57%) were identified as "possible" or "likely" to have LGS using REST-LGS. SIGNIFICANCE: In this analysis, the validated REST-LGS was evaluated in a real-world setting. The majority of previously undiagnosed patients were identified via REST-LGS as "possible" or "likely" to have LGS. Extensive missing data highlights challenges of LGS diagnosis in adults. PLAIN LANGUAGE SUMMARY: There is a need to identify adult patients with Lennox-Gastaut syndrome (LGS) so they can receive appropriate treatment. The Refractory Epilepsy Screening Tool for LGS (REST-LGS) questionnaire was designed by experts to identify whether patients with seizures that are not controlled by medications may have LGS. In this study, 2 physicians completed the REST-LGS using charts for 100 patients who experience seizures not controlled by medications. Of the patients who were previously diagnosed as not having LGS, the majority were "likely" or "possible" to have LGS based on the REST-LGS; therefore, the REST-LGS can identify patients for further evaluation.

Optimal dose of fenfluramine in adjuvant treatment of drug-resistant epilepsy: evidence from randomized controlled trials.

Objective: Several clinical trials have suggested that fenfluramine (FFA) is effective for the treatment of epilepsy in Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS). However, the exploration of its optimal target dose is ongoing. This study aimed to summarize the best evidence to inform this clinical issue. Materials and methods: We searched PubMed, Embase (via Ovid), and Web of Science for relevant literature published before December 1st, 2023. Randomized, double-blind, placebo-controlled studies that evaluated the efficacy, safety, and tolerability of FFA in DS and LGS were identified and meta-analysis was performed according to doses. The study was registered with PROSPERO (CRD42023392454). Results: Six hundred and twelve patients from four randomized controlled trials were enrolled. The results demonstrated that FFA at 0.2, 0.4, or 0.7 mg/kg/d showed significantly greater efficacy compared to placebo in terms of at least 50% reduction (p < 0.001, p < 0.001, p < 0.001) and at least 75% reduction (p < 0.001, p = 0.007, p < 0.001) in monthly seizure frequency from baseline. Moreover, significantly more patients receiving FFA than placebo were rated as much improved or very much improved in CGI-I by both caregivers/parents and investigators (p < 0.001). The most common treatment-emergent adverse events were decreased appetite, diarrhea, fatigue, and weight loss, with no valvular heart disease or pulmonary hypertension observed in any participant. For dose comparison, 0.7 mg/kg/d group presented higher efficacy on at least 75% reduction in seizure (p = 0.006) but not on at least 50% reduction. Weight loss (p = 0.002), decreased appetite (p = 0.04), and all-cause withdrawal (p = 0.036) were more common in 0.7 mg/kg/d group than 0.2 mg/kg/d. There was no statistical difference in other safety parameters between these two groups. Conclusion: The higher range of the licensed dose achieves the optimal balance between efficacy, safety, and tolerability in patients with DS and LGS. Clinical trial registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023392454.