Relationship of Lennox-Gastaut syndrome with perinatal event: A cross-sectional study

A comprehensive systematic literature review of the burden of illness of Lennox-Gastaut syndrome on patients, caregivers, and society

Fully elucidating the burden that Lennox-Gastaut syndrome (LGS) places on individuals with the disease and their caregivers is critical to improving outcomes and quality of life (QoL). This systematic literature review evaluated the global burden of illness of LGS, including clinical symptom burden, care requirements, QoL, comorbidities, caregiver burden, economic burden, and treatment burden (PROSPERO ID: CRD42022317413). MEDLINE, Embase, and the Cochrane Library were searched for articles that met predetermined criteria. After screening 1442 deduplicated articles and supplementary manual searches, 113 articles were included for review. A high clinical symptom burden of LGS was identified, with high seizure frequency and nonseizure symptoms (including developmental delay and intellectual disability) leading to low QoL and substantial care requirements for individuals with LGS, with the latter including daily function assistance for mobility, eating, and toileting. Multiple comorbidities were identified, with intellectual disorders having the highest prevalence. Although based on few studies, a high caregiver burden was also identified, which was associated with physical problems (including fatigue and sleep disturbances), social isolation, poor mental health, and financial difficulties. Most economic analyses focused on the high direct costs of LGS, which arose predominantly from medically treated seizure events, inpatient costs, and medication requirements. Pharmacoresistance was common, and many individuals required polytherapy and treatment changes over time. Few studies focused on the humanistic burden. Quality concerns were noted for sample representativeness, disease and outcome measures, and reporting clarity. In summary, a high burden of LGS on individuals, caregivers, and health care systems was identified, which may be alleviated by reducing the clinical symptom burden. These findings highlight the need for a greater understanding of and better definitions for the broad spectrum of LGS symptoms and development of treatments to alleviate nonseizure symptoms.

Efficacy and Safety of Fenfluramine for the Treatment of Seizures Associated With Lennox-Gastaut Syndrome: A Randomized Clinical Trial

Question

Is adjunctive fenfluramine effective in patients with Lennox-Gastaut syndrome (LGS)?

Findings

In this randomized clinical trial of 263 patients with LGS, use of 0.7-mg/kg/d fenfluramine resulted in a greater reduction in drop seizures than with placebo, more patients achieving a 50% or greater reduction in drop seizure frequency, and greater reduction in generalized tonic-clonic seizure frequency. Treatment-emergent adverse events included decreased appetite, but no patient developed valvular heart disease or pulmonary hypertension.

Meaning

Findings from this trial suggest that fenfluramine may be a safe and effective treatment option for patients with LGS.

Importance

New treatment options are needed for patients with Lennox-Gastaut syndrome (LGS), a profoundly impairing, treatment-resistant, developmental and epileptic encephalopathy.

Objective

To evaluate the efficacy and safety of fenfluramine in patients with LGS.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled, parallel-group randomized clinical trial was conducted from November 27, 2017, to October 25, 2019, and had a 20-week trial duration. Patients were enrolled at 65 study sites in North America, Europe, and Australia. Included patients were aged 2 to 35 years with confirmed diagnosis of LGS and experienced 2 or more drop seizures per week during the 4-week baseline. Using a modified intent-to-treat method, data analysis was performed from November 27, 2017, to October 25, 2019. The database lock date was January 30, 2020, and the date of final report was September 11, 2021.

Interventions

Patients were randomized to receive either a 0.7-mg/kg/d or 0.2-mg/kg/d (maximum 26 mg/d) dose of fenfluramine or placebo. After titration (2-week period), patients were taking their randomized dose for 12 additional weeks.

Main Outcomes and Measures

Primary efficacy end point was percentage change from baseline in drop seizure frequency in patients who received 0.7 mg/kg/d of fenfluramine vs placebo.

Results

A total of 263 patients (median [range] age, 13 [2-35] years; 146 male patients [56%]) were randomized to the 0.7-mg/kg/d fenfluramine group (n = 87), 0.2-mg/kg/d fenfluramine group (n = 89), or placebo group (n = 87). The median percentage reduction in frequency of drop seizures was 26.5 percentage points in the 0.7-mg/kg/d fenfluramine group, 14.2 percentage points in the 0.2-mg/kg/d fenfluramine group, and 7.6 percentage points in the placebo group. The trial met its primary efficacy end point: patients in the 0.7-mg/kg/d fenfluramine group achieved a −19.9 percentage points (95% CI, −31.0 to −8.7 percentage points; P = .001) estimated median difference in drop seizures from baseline vs placebo. More patients in the 0.7-mg/kg/d fenfluramine group achieved a 50% or greater response (22 of 87 [25%]; P = .02) vs placebo (9 of 87 [10%]). Site investigators and caregivers gave a much improved or very much improved rating on the Clinical Global Impression of Improvement scale to more patients in the 0.7-mg/kg/d fenfluramine group than patients in the placebo group (21 [26%] vs 5 [6%]; P = .001). The seizure subtype that appeared most responsive to fenfluramine was generalized tonic-clonic seizure (120 of 263 [46%]), with a decrease in frequency of 45.7% in the 0.7-mg/kg/d fenfluramine group and 58.2% in the 0.2-mg/kg/d fenfluramine group compared with an increase of 3.7% in the placebo group. Most common treatment-emergent adverse events included decreased appetite (59 [22%]), somnolence (33 [13%]), and fatigue (33 [13%]). No cases of valvular heart disease or pulmonary arterial hypertension were observed.

Conclusions and Relevance

Results of this trial showed that, in patients with LGS, fenfluramine compared with placebo provided a significantly greater reduction in drop seizures and may be a particularly advantageous choice in patients who experience generalized tonic-clonic seizures.

Trial Registration

ClinicalTrials.gov Identifier: NCT03355209

Lennox-Gastaut Syndrome: A Prospective Follow-up Study

Objectives:

Lennox–Gastaut syndrome is a catastrophic epileptic encephalopathy. In Lennox–Gastaut syndrome, seizures are resistant to pharmacological treatment. In this prospective study, we evaluated the clinical features, neuroimaging, and response to treatment.

Materials and Methods:

Forty-three consecutive newly diagnosed patients of Lennox–Gastaut syndrome were enrolled in the study. Baseline clinical assessment included seizure semiology, seizure frequency, electroencephalography, and neuroimaging. Patients were treated with combinations of preferred antiepileptic drugs (sodium valproate [VPA], clobazam [CLB], levetiracetam [LVT], lamotrigine [LMT], and topiramate [TPM]). Patients were followed for 6 months. The outcome was assessed using modified Barthel index.

Results:

Tonic and generalized tonic-clonic forms were the most common seizures types. Features suggestive of hypoxic-ischemic encephalopathy (37.2%) were most frequent neuroimaging abnormality. Neuroimaging was normal in 32.6% of patients. With a combination valproic acid (VPA), CLB, and LVT, in 81.4% of patients, we were able to achieve >50% reduction in seizure frequency. Eleven (25.58%) patients showed an improvement in the baseline disability status.

Conclusions:

A combination of VPA, CLB, and LVT is an appropriate treatment regimen for patients with Lennox–Gastaut syndrome.