Chu, Catherine J

Abstract Objective This study was undertaken to evaluate the response to second treatments for infantile epileptic spasms syndrome (IESS). Methods Infants aged 2–24 months with IESS were prospectively enrolled in the National Infantile Spasms Cohort study at 21 pediatric epilepsy centers in the United States from 2012 to 2018. We analyzed data from infants who initially received standard treatment (hormonal therapy [adrenocorticotropic hormone, high‐dose prednisolone] or vigabatrin), had continued or recurring epileptic spasms, and received a second treatment. We excluded those with tuberous sclerosis. Treatment groups included hormonal therapy followed by vigabatrin (reference), hormonal‐to‐hormonal, hormonal‐to‐nonstandard, vigabatrin‐to‐hormonal, and vigabatrin‐to‐nonstandard. Nonstandard treatments included other antiseizure medications and dietary therapy. Treatment groups were tested for differences in 3‐month clinical remission using a binary logistic regression to estimate odds ratios (ORs). Results There were 153 infants with IESS who received second treatments. The highest rates of 3‐month remission were among infants in the hormonal‐to‐vigabatrin (22/65, 34%) and vigabatrin‐to‐hormonal (9/26, 35%) groups, followed by vigabatrin‐to‐nonstandard (3/10, 30%), hormonal‐to‐hormonal (4/22, 18%), and hormonal‐to‐nonstandard (1/30, 3.3%). Compared to the hormonal‐to‐vigabatrin group (reference), fewer infants had remission in the hormonal‐to‐nonstandard group (OR = .07, 95% confidence interval [CI] = .01–.53), and there was a trend toward fewer infants in the hormonal‐to‐hormonal group (OR = .43, 95% CI = .13–1.4, p = .17). Following initial hormonal treatment, the number needed to treat was three infants for one additional infant to have remission when treated with vigabatrin compared to nonstandard therapy as the second treatment. Significance This updated analysis with an expanded sample size provided power for additional subgroup analysis. Overall response rates were low, and at best only one third had remission after second treatment. Results support a clinical strategy of switching mechanism of action when selecting a second medication for epileptic spasms (i.e., use vigabatrin after hormonal therapy, or hormonal therapy after vigabatrin). Our findings also support the use of standard over nonstandard therapies.

Abstract We evaluated whether spike ripples, the combination of epileptiform spikes and ripples, provide a reliable and improved biomarker for the epileptogenic zone compared with other leading interictal biomarkers in a multicentre, international study. We first validated an automated spike ripple detector on intracranial EEG recordings. We then applied this detector to subjects from four centres who subsequently underwent surgical resection with known 1-year outcomes. We evaluated the spike ripple rate in subjects cured after resection [International League Against Epilepsy Class 1 outcome (ILAE 1)] and those with persistent seizures (ILAE 2–6) across sites and recording types. We also evaluated available interictal biomarkers: spike, spike-gamma, wideband high frequency oscillation (HFO, 80–500 Hz), ripple (80–250 Hz) and fast ripple (250–500 Hz) rates using previously validated automated detectors. The proportion of resected events was computed and compared across subject outcomes and biomarkers. Overall, 109 subjects were included. Most spike ripples were removed in subjects with ILAE 1 outcome (P < 0.001), and this was qualitatively observed across all sites and for depth and subdural electrodes (P < 0.001 and P < 0.001, respectively). Among ILAE 1 subjects, the mean spike ripple rate was higher in the resected volume (0.66/min) than in the non-removed tissue (0.08/min, P < 0.001). A higher proportion of spike ripples were removed in subjects with ILAE 1 outcomes compared with ILAE 2–6 outcomes (P = 0.06). Among ILAE 1 subjects, the proportion of spike ripples removed was higher than the proportion of spikes (P < 0.001), spike-gamma (P < 0.001), wideband HFOs (P < 0.001), ripples (P = 0.009) and fast ripples (P = 0.009) removed. At the individual level, more subjects with ILAE 1 outcomes had the majority of spike ripples removed (79%, 38/48) than spikes (69%, P = 0.12), spike-gamma (69%, P = 0.12), wideband HFOs (63%, P = 0.03), ripples (45%, P = 0.01) or fast ripples (36%, P < 0.001) removed. Thus, in this large, multicentre cohort, when surgical resection was successful, the majority of spike ripples were removed. Furthermore, automatically detected spike ripples localize the epileptogenic tissue better than spikes, spike-gamma, wideband HFOs, ripples and fast ripples.

ObjectiveThe aim of this study was to determine whether selection of treatment for children with infantile spasms (IS) varies by race/ethnicity.MethodsThe prospective US National Infantile Spasms Consortium database includes children with IS treated from 2012 to 2018. We examined the relationship between race/ethnicity and receipt of standard IS therapy (prednisolone, adrenocorticotropic hormone, vigabatrin), adjusting for demographic and clinical variables using logistic regression. Our primary outcome was treatment course, which considered therapy prescribed for the first and, when needed, the second IS treatment together.ResultsOf 555 children, 324 (58%) were non‐Hispanic white, 55 (10%) non‐Hispanic Black, 24 (4%) non‐Hispanic Asian, 80 (14%) Hispanic, and 72 (13%) other/unknown. Most (398, 72%) received a standard treatment course. Insurance type, geographic location, history of prematurity, prior seizures, developmental delay or regression, abnormal head circumference, hypsarrhythmia, and IS etiologies were associated with standard therapy. In adjusted models, non‐Hispanic Black children had lower odds of receiving a standard treatment course compared with non‐Hispanic white children (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.20–0.89; p = 0.02). Adjusted models also showed that children with public (vs. private) insurance had lower odds of receiving standard therapy for treatment 1 (OR, 0.42; CI, 0.21–0.84; p = 0.01).InterpretationNon‐Hispanic Black children were more often treated with non‐standard IS therapies than non‐Hispanic white children. Likewise, children with public (vs. private) insurance were less likely to receive standard therapies. Investigating drivers of inequities, and understanding the impact of racism on treatment decisions, are critical next steps to improve care for patients with IS. ANN NEUROL 2022;92:32–44

Summary: High-density EEG (HD-EEG) recordings use a higher spatial sampling of scalp electrodes than a standard 10-20 low-density EEG montage. Although several studies have demonstrated improved localization of the epileptogenic cortex using HD-EEG, widespread implementation is impeded by cost, setup and interpretation time, and lack of specific or sufficient procedural billing codes. Despite these barriers, HD-EEG has been in use at several institutions for years. These centers have noted utility in a variety of clinical scenarios where increased spatial resolution from HD-EEG has been required, justifying the extra time and cost. We share select scenarios from several centers, using different recording techniques and software, where HD-EEG provided information above and beyond the standard low-density EEG. We include seven cases where HD-EEG contributed directly to current clinical care of epilepsy patients and highlight two novel techniques which suggest potential opportunities to improve future clinical care. Cases illustrate how HD-EEG allows clinicians to: case 1—lateralize falsely generalized interictal epileptiform discharges; case 2—improve localization of falsely generalized epileptic spasms; cases 3 and 4—improve localization of interictal epileptiform discharges in anatomic regions below the circumferential limit of standard low-density EEG coverage; case 5—improve noninvasive localization of the seizure onset zone in lesional epilepsy; cases 6 and 7—improve localization of the seizure onset zone to guide invasive investigation near eloquent cortex; case 8—identify epileptic fast oscillations; and case 9—map language cortex. Together, these nine cases illustrate that using both visual analysis and advanced techniques, HD-EEG can play an important role in clinical management.

OBJECTIVES: We assessed the adherence to neuroimaging guidelines and the diagnostically relevant yield of neuroimaging in newly presenting early life epilepsy (ELE). METHODS: There were 775 children with a new diagnosis of epilepsy (<3 years old at onset) who were recruited through the ELE study at 17 US pediatric epilepsy centers (2012–2015) and managed prospectively for 1 year. The data were analyzed to assess the proportion of children who underwent neuroimaging, the type of neuroimaging, and abnormalities. RESULTS: Of 725 children (93.5%) with neuroimaging, 714 had an MRI (87% with seizure protocols) and 11 had computed tomography or ultrasound only. Etiologically relevant abnormalities were present in 290 individuals (40%) and included: an acquired injury in 97 (13.4%), malformations of cortical development in 56 (7.7%), and other diffuse disorders of brain development in 51 (7.0%). Neuroimaging was abnormal in 160 of 262 (61%) children with abnormal development at diagnosis versus 113 of 463 (24%) children with typical development. Neuroimaging abnormalities were most common in association with focal seizure semiology (40%), spasms (47%), or unclear semiology (42%). In children without spasms or focal semiology with typical development, 29 of 185 (16%) had imaging abnormalities. Pathogenic genetic variants were identified in 53 of 121 (44%) children with abnormal neuroimaging in whom genetic testing was performed. CONCLUSIONS: Structural abnormalities occur commonly in ELE, and adherence to neuroimaging guidelines is high at US pediatric epilepsy centers. These data support the universal adoption of imaging guidelines because the yield is substantially high, even in the lowest risk group.

SummaryObjectiveThe multicenter National Infantile Spasms Consortium prospective cohort was used to compare outcomes and phenotypic features of patients with infantile spasms with and without hypsarrhythmia.MethodsPatients aged 2 months to 2 years were enrolled prospectively with new‐onset infantile spasms. Treatment choice and categorization of hypsarrhythmia were determined clinically at each site. Response to therapy was defined as resolution of clinical spasms (and hypsarrhythmia if present) without relapse 3 months after initiation.ResultsEighty‐two percent of patients had hypsarrhythmia, but this was not associated with gender, mean age, preexisting developmental delay or epilepsy, etiology, or response to first‐line therapy. Infants with hypsarrhythmia were more likely to receive standard treatment (adrenocorticotropic hormone, prednisolone, or vigabatrin [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.4–4.7] and preexisting epilepsy reduced the likelihood of standard treatment (OR3.2, 95%CI1.9–5.4). Hypsarrhythmia was not a determinant of response to treatment. A logistic regression model demonstrated that later age of onset (OR1.09 per month, 95%CI1.03–1.15) and absence of preexisting epilepsy (OR1.7, 95%CI1.06–2.81) had a small impact on the likelihood of responding to the first‐line treatment. However, receiving standard first‐line treatment increased the likelihood of responding dramatically: vigabatrin (OR5.2 ,95%CI2–13.7), prednisolone (OR8, 95%CI3.1–20.6), and adrenocorticotropic hormone (ACTH;OR10.2, 95%CI4.1–25.8) .SignificanceFirst‐line treatment with standard therapy was by far the most important variable in determining likelihood of response to treatment of infantile spasms with or without hypsarrhythmia.