Genetic Testing to Inform Epilepsy Treatment Management From an International Study of Clinical Practice

Importance

It is currently unknown how often and in which ways a genetic diagnosis given to a patient with epilepsy is associated with clinical management and outcomes.

Objective

To evaluate how genetic diagnoses in patients with epilepsy are associated with clinical management and outcomes.

Design, Setting, and Participants

This was a retrospective cross-sectional study of patients referred for multigene panel testing between March 18, 2016, and August 3, 2020, with outcomes reported between May and November 2020. The study setting included a commercial genetic testing laboratory and multicenter clinical practices. Patients with epilepsy, regardless of sociodemographic features, who received a pathogenic/likely pathogenic (P/LP) variant were included in the study. Case report forms were completed by all health care professionals.

Exposures

Genetic test results.

Main Outcomes and Measures

Clinical management changes after a genetic diagnosis (ie, 1 P/LP variant in autosomal dominant and X-linked diseases; 2 P/LP variants in autosomal recessive diseases) and subsequent patient outcomes as reported by health care professionals on case report forms.

Results

Among 418 patients, median (IQR) age at the time of testing was 4 (1-10) years, with an age range of 0 to 52 years, and 53.8% (n = 225) were female individuals. The mean (SD) time from a genetic test order to case report form completion was 595 (368) days (range, 27-1673 days). A genetic diagnosis was associated with changes in clinical management for 208 patients (49.8%) and usually (81.7% of the time) within 3 months of receiving the result. The most common clinical management changes were the addition of a new medication (78 [21.7%]), the initiation of medication (51 [14.2%]), the referral of a patient to a specialist (48 [13.4%]), vigilance for subclinical or extraneurological disease features (46 [12.8%]), and the cessation of a medication (42 [11.7%]). Among 167 patients with follow-up clinical information available (mean [SD] time, 584 [365] days), 125 (74.9%) reported positive outcomes, 108 (64.7%) reported reduction or elimination of seizures, 37 (22.2%) had decreases in the severity of other clinical signs, and 11 (6.6%) had reduced medication adverse effects. A few patients reported worsening of outcomes, including a decline in their condition (20 [12.0%]), increased seizure frequency (6 [3.6%]), and adverse medication effects (3 [1.8%]). No clinical management changes were reported for 178 patients (42.6%).

Conclusions and Relevance

Results of this cross-sectional study suggest that genetic testing of individuals with epilepsy may be materially associated with clinical decision-making and improved patient outcomes.

Safety and efficacy of ganaxolone in patients with CDKL5 deficiency disorder: results from the double-blind phase of a randomised, placebo-controlled, phase 3 trial

BACKGROUND

CDKL5 deficiency disorder (CDD) is a rare, X-linked, developmental and epileptic encephalopathy characterised by severe global developmental impairment and seizures that can begin in the first few months after birth and are often treatment refractory. Ganaxolone, an investigational neuroactive steroid, reduced seizure frequency in an open-label, phase 2 trial that included patients with CDD. We aimed to further assess the efficacy and safety of ganaxolone in patients with CDD-associated refractory epilepsy.

METHODS

In the double-blind phase of this randomised, placebo-controlled, phase 3 trial, done at 39 outpatient clinics in eight countries (Australia, France, Israel, Italy, Poland, Russia, the UK, and the USA), patients were eligible if they were aged 2-21 years with a pathogenic or probably pathogenic CDKL5 variant and at least 16 major motor seizures (defined as bilateral tonic, generalised tonic-clonic, bilateral clonic, atonic, or focal to bilateral tonic-clonic) per 28 days in each 4-week period of an 8-week historical period. After a 6-week prospective baseline period, patients were randomly assigned (1:1) via an interactive web response system to receive either enteral adjunctive ganaxolone or matching enteral adjunctive placebo (maximum dose 63 mg/kg per day for patients weighing ≤28 kg or 1800 mg/day for patients weighing >28 kg) for 17 weeks. Patients, caregivers, investigators (including those analysing data), trial staff, and the sponsor (other than the investigational product manager) were masked to treatment allocation. The primary efficacy endpoint was percentage change in median 28-day major motor seizure frequency from the baseline period to the 17-week double-blind phase and was analysed (using a Wilcoxon-rank sum test) in all patients who received at least one dose of trial treatment and for whom baseline data were available. Safety (compared descriptively across groups) was analysed in all patients who received at least one dose of trial treatment. This study is registered with ClinicalTrials.gov, NCT03572933, and the open-label extension phase is ongoing.

FINDINGS

Between June 25, 2018, and July 2, 2020, 114 patients were screened for eligibility, of whom 101 (median age 6 years [IQR 3 to 10]) were randomly assigned to receive either ganaxolone (n=50) or placebo (n=51). All patients received at least one dose of a study drug, but seizure frequency for one patient in the ganaxolone group was not recorded at baseline and so the primary endpoint was analysed in a population of 100 patients. There was a median percentage change in 28-day major motor seizure frequency of -30·7% (IQR -49·5 to -1·9) in the ganaxolone group and of -6·9% (-24·1 to 39·7) in the placebo group (p=0·0036). The Hodges-Lehmann estimate of median difference in responses to ganaxolone versus placebo was -27·1% (95% CI -47·9 to - 9·6). Treatment-emergent adverse events occurred in 43 (86%) of 50 patients in the ganaxolone group and in 45 (88%) of 51 patients in the placebo group. Somnolence, pyrexia, and upper respiratory tract infections occurred in at least 10% of patients in the ganaxolone group and more frequently than in the placebo group. Serious adverse events occurred in six (12%) patients in the ganaxolone group and in five (10%) patients in the placebo group. Two (4%) patients in the ganaxolone group and four (8%) patients in the placebo group discontinued the trial. There were no deaths in the double-blind phase.

INTERPRETATION

Ganaxolone significantly reduced the frequency of CDD-associated seizures compared with placebo and was generally well tolerated. Results from what is, to our knowledge, the first controlled trial in CDD suggest a potential treatment benefit for ganaxolone. Long-term treatment is being assessed in the ongoing open-label extension phase of this trial.

FUNDING

Marinus Pharmaceuticals.

Impact of Nonclinical Factors on Treatment Decisions: What Can and Cannot Be Done and Why?

This clinical scenario describes a situation where drug-resistant focal epilepsy could have been treated with specific surgery, but a mixture of nonclinical factors led to a different management. The epilepsy started at the age of 6 years and the assessment for other treatment options by this team was done at the age of 12 years. Financial factors were important in the decisions that had to be made and effectively perhaps decisive.

Recent developments in the surgical management of paediatric epilepsy

Among the 1% of children affected by epilepsy, failure of pharmacological therapy and early age of seizure onset can lead to worse long-term cognitive outcomes, mental health disorders and impaired functional status. Surgical management often improves functional and cognitive outcomes in children with medically refractory epilepsy, especially when seizure remission is achieved. However, surgery remains underused in children with drug-resistant epilepsy, creating a large treatment gap. Several recent innovations have led to considerable improvement in surgical technique, including the recent development of minimally invasive diagnostic and therapeutic techniques such as stereotactic EEG, transcranial magnetic stimulation, MRI-guided laser ablation, as well as novel paradigms of neurostimulation. This article discusses the current landscape of surgical innovation in the management of paediatric epilepsy, leading to a paradigm shift towards minimally invasive therapy and closing the treatment gap in children suffering from drug-resistant seizures.

Research conference summary from the 2014 International Task Force on ATP1A3-Related Disorders

Objective:

ATP1A3-related neurologic disorders encompass a broad range of phenotypes that extend well beyond initial phenotypic criteria associated with alternating hemiplegia of childhood (AHC) and rapid-onset dystonia parkinsonism.

Methods:

In 2014, the Alternating Hemiplegia of Childhood Foundation hosted a multidisciplinary workshop intended to address fundamental challenges surrounding the diagnosis and management of individuals with ATP1A3-related disorders.

Results:

Workshop attendees were charged with the following: (1) to achieve consensus on expanded diagnostic criteria to facilitate the identification of additional patients, intended to supplement existing syndrome-specific diagnostic paradigms; (2) to standardize definitions for the broad range of paroxysmal manifestations associated with AHC to disseminate to families; (3) to create clinical recommendations for common recurrent issues facing families and medical care providers; (4) to review data related to the death of individuals in the Alternating Hemiplegia of Childhood Foundation database to guide future efforts in identifying at-risk subjects and potential preventative measures; and (5) to identify critical gaps where we most need to focus national and international research efforts.

Conclusions:

This report summarizes recommendations of the workshop committee, highlighting the key phenotypic features to facilitate the diagnosis of possible ATP1A3 mutations, providing recommendations for genetic testing, and outlining initial acute management for common recurrent clinical conditions, including epilepsy.

Rasmussen encephalitis with dual pathology in a patient without seizures: case report and literature review

PURPOSE

Rasmussen encephalitis without seizures is rare. We report a case of Rasmussen encephalitis and cortical dysplasia without epilepsy as well as describe the imaging, pathology, and clinical course and review the literature to investigate whether this may represent a rare subset of Rasmussen encephalitis.

CASE REPORT

We report the case of a 12-year-old girl with a history of cognitive decline and right arm weakness. Magnetic resonance imaging demonstrated diffuse left hemispheric cortical and subcortical atrophy suggestive of Rasmussen encephalitis. The patient had no clinical history of seizures, and electroencephalography did not demonstrate epileptiform abnormalities. Craniotomy for open brain biopsy was performed, and histopathologic evaluation identified Rasmussen encephalitis with cortical dysplasia (dual pathology).

CONCLUSIONS

To the best of our knowledge, this is the third case of Rasmussen encephalitis diagnosed by both imaging and histopathology that had no clinical or electroencephalographic evidence of seizures and is the only case of Rasmussen encephalitis with cortical dysplasia without epilepsy.

Induction of mild hypothermia by noninvasive body cooling in healthy, unanesthetized subjects

The induction of mild hypothermia has been considered as an important means to provide protection against cerebral ischemia. Yet, to date, the relative clinical efficacies of different noninvasive methods for reducing core body temperature have not been thoroughly studied. The aim of the current investigation was to compare the relative effectiveness of several noninvasive cooling techniques for reducing core temperatures in healthy volunteers. Cooling methods included convective/conductive and evaporative/conductive combinations, as well as evaporative cooling alone. Additionally, focal facial warming was employed as a means to suppress involuntary motor activity and thus better enable noninvasive cooling. Core temperatures were measured so to monitor the relative efficiencies of these induced cooling methodologies. With each employed methodology, rectal temperature reductions were induced, with combined evaporative/conductive (n=4, 1.44°C±0.99°C) and convective/conductive (n=4, 1.51°C±0.89°C) approaches yielding the largest decreases: note, that evaporative cooling alone was not as efficient in lowering core body temperature (n=10, 0.56°C±0.20°C; n=16, 0.58°C±0.27°C). In this study on healthy volunteers, the evaporative/conductive and convective/conductive combination methods were more effective in reducing core temperatures as compared with an evaporative approach alone. These therapeutic approaches for the induction of mild hypothermia (including the use of facial warming) could be employed in warranted clinical cases, importantly without the need for administration of anesthetics or paralytics.

Alternating hemiplegia of childhood: early characteristics and evolution of a neurodevelopmental syndrome

OBJECTIVES

Alternating hemiplegia of childhood is a predominantly sporadic neurodevelopmental syndrome of uncertain etiology. In more than 3 decades since its description, little progress has been made in understanding its etiology or in identifying effective treatments. In 1998, in collaboration with the Alternating Hemiplegia of Childhood Foundation, an international registry was established to help document clinical outcomes and promote research efforts.

PATIENTS AND METHODS

We present phenotypic data on 103 patients who met existing diagnostic criteria for alternating hemiplegia of childhood. Although some of these subjects may have been included in previously published reviews, our focus was directed toward the earliest manifestations of symptoms and evolution of features over time. Data sources included written questionnaires, face-to-face and telephone interviews, clinical examination, and medical charts. Characteristics of disease onset, medical comorbidities, episode triggers, diagnostic workup, and treatment are presented.

RESULTS

Paroxysmal eye movements were the most frequent early symptom, manifesting in the first 3 months of life in 83% of patients. Hemiplegic episodes appeared by 6 months of age in 56% of infants. Background slowing shown by electroencephalography during typical paroxysmal events, including hemiplegic, tonic, or dystonic episodes was frequent (21 of 42 cases). Distinct convulsive episodes with altered consciousness believed to be epileptic in nature were reported in 41% of patients. Ataxia (96%) and cognitive impairment (100%) were frequent nonepisodic symptoms. Empiric pharmacologic treatment approaches offered little benefit in most subjects and resulted in adverse effects in 20% of patients. Prolonged episodes were completely or temporarily aborted during sleep in all subjects.

CONCLUSIONS

This descriptive analysis of a large cohort of children indicates that paroxysmal ocular movements are an early, highly suggestive symptom, followed by paroxysmal episodes of focal dystonia or flaccid, alternating hemiplegia in early infancy in the majority of subjects. Current challenges in diagnosis and management contribute to poor outcomes. Early diagnosis and multicenter collaboration are needed to facilitate trials to identify more effective therapies.

Shiver suppression using focal hand warming in unanesthetized normal subjects

BACKGROUND

A decrease of 1 or 2 degrees C in core temperature may provide protection against cerebral ischemia. However, during corporeal cooling of unanesthetized patients, the initiation of involuntary motor activity (shiver) prevents the reduction of core temperature. The authors' laboratory previously showed that focal facial warming suppressed whole-body shiver. The aim of the current study was to determine whether the use of hand warming alone could suppress shiver in unanesthetized subjects and hence potentiate core cooling.

METHODS

Subjects (n = 8; healthy men) were positioned supine on a circulating water mattress (8-15 degrees C) with a convective-air coverlet (14 degrees C) extending from their necks to their feet. A dynamic protocol was used in which focal hand warming was used to suppress involuntary motor activity, enabling noninvasive cooling to decrease core temperatures. The following parameters were monitored: (1) heart rate; (2) blood pressure; (3) core temperature (rectal, tympanic); (4) cutaneous temperature and heat flux; (5) subjective shiver level (SSL scale 0-10) and thermal comfort index (scale 0-10); (6) metabolic data (n = 6); and (7) electromyograms.

RESULTS

During cooling without hand warming, involuntary motor activity increased until it was widespread. After subjects reported whole-body shiver (SSL > or = 7), applied hand warming, in all cases, reduced shiver levels (SSL < o r= 3), decreased electromyographic root mean square amplitudes, and allowed core temperature to decrease from 37.0 +/- 0.2 to 35.9 +/- 0.5 degrees C (measured rectally).

CONCLUSIONS

Focal hand warming seems to be valuable in minimizing or eliminating the need to suppress involuntary motor activity pharmacologically when it is desired to induce or maintain mild hypothermia; it may be used in conjunction with facial warming or in cases in which facial warming is contraindicated.