Computational EEG attributes predict response to therapy for epileptic spasms.

OBJECTIVE: We set out to evaluate whether response to treatment for epileptic spasms is associated with specific candidate computational EEG biomarkers, independent of clinical attributes. METHODS: We identified 50 children with epileptic spasms, with pre- and post-treatment overnight video-EEG. After EEG samples were preprocessed in an automated fashion to remove artifacts, we calculated amplitude, power spectrum, functional connectivity, entropy, and long-range temporal correlations (LRTCs). To evaluate the extent to which each feature is independently associated with response and relapse, we conducted logistic and proportional hazards regression, respectively. RESULTS: After statistical adjustment for the duration of epileptic spasms prior to treatment, we observed an association between response and stronger baseline and post-treatment LRTCs (P = 0.042 and P = 0.004, respectively), and higher post-treatment entropy (P = 0.003). On an exploratory basis, freedom from relapse was associated with stronger post-treatment LRTCs (P = 0.006) and higher post-treatment entropy (P = 0.044). CONCLUSION: This study suggests that multiple EEG features-especially LRTCs and entropy-may predict response and relapse. SIGNIFICANCE: This study represents a step toward a more precise approach to measure and predict response to treatment for epileptic spasms.

Epileptic spasms relapse is associated with response latency but not conventional attributes of post-treatment EEG.

OBJECTIVE: Relapse of epileptic spasms after initial treatment of infantile epileptic spasms syndrome (IESS) is common. However, past studies of small cohorts have inconsistently linked relapse risk to etiology, treatment modality, and EEG features upon response. Using a large single-center IESS cohort, we set out to quantify the risk of epileptic spasms relapse and identify specific risk factors. METHODS: We identified all children with epileptic spasms at our center using a clinical EEG database. Using the electronic medical record, we confirmed IESS syndrome classification and ascertained treatment, response, time to relapse, etiology, EEG features, and other demographic factors. Relapse-free survival analysis was carried out using Cox proportional hazards regression. RESULTS: Among 599 children with IESS, 197 specifically responded to hormonal therapy and/or vigabatrin (as opposed to surgery or other second-line treatments). In this study, 41 (21%) subjects exhibited relapse of epileptic spasms within 12 months of response. Longer duration of IESS prior to response (>3 months) was strongly associated with shorter latency to relapse (hazard ratio = 3.11; 95% CI 1.59-6.10; p = 0.001). Relapse was not associated with etiology, developmental status, or any post-treatment EEG feature. SIGNIFICANCE: This study suggests that long duration of IESS before response is the single largest clinical predictor of relapse risk, and therefore underscores the importance of prompt and successful initial treatment. Further study is needed to evaluate candidate biomarkers of epileptic spasms relapse and identify treatments to mitigate this risk. PLAIN LANGUAGE SUMMARY: Relapse of infantile spasms is common after initially successful treatment. With study of a large group of children with infantile spasms, we determined that relapse is linked to long duration of infantile spasms. In contrast, relapse was not associated with the cause of infantile spasms, developmental measures, or EEG features at the time of initial response. Further study is needed to identify tools to predict impending relapse of infantile spasms.

Long-term treatment with ganaxolone for seizures associated with cyclin-dependent kinase-like 5 deficiency disorder: Two-year open-label extension follow-up.

OBJECTIVE: In the placebo-controlled, double-blind phase of the Marigold study (NCT03572933), ganaxolone significantly reduced major motor seizure frequency (MMSF) in patients with cyclin-dependent kinase-like 5 deficiency disorder (CDD). We report 2-year safety and clinical outcomes data from the open-label extension (OLE) phase of Marigold. METHODS: Patients with CDD who completed the double-blind phase were eligible to continue in the OLE. Efficacy assessments included MMSF reduction from prerandomization baseline, responder rates, and Clinical Global Impression-Improvement scores, including assessment of seizure intensity and duration (CGI-CSID). Safety assessments included treatment-emergent adverse events (TEAEs) and TEAEs leading to discontinuation. RESULTS: Of 101 patients who enrolled in Marigold, 88 (87.1%) entered the OLE (median age = 5 years, 79.5% female). Median 28-day MMSF at baseline was 50.6. At 2 years in the OLE (months 22-24), MMSF was reduced by a median of 48.2% (n = 50); when missing data were imputed, median reduction in MMSF was 43.8% using a mixed effects model and 27.4% using a last observation carried forward model. During months 22-24, 23 of 50 (46.0%) patients experienced reductions in MMSF of ≥50%; 12 of 50 (24.0%) patients experienced MMSF reductions of ≥75%. During months 22-24, 40 of 49 (81.6%) patients were rated by caregivers as having improvement in seizure-related outcomes based on CGI-CSID scores. Thirty-seven patients discontinued ganaxolone due to lack of efficacy (n = 13), withdrawal by caregiver (n = 12), adverse event (n = 10), physician decision (n = 1), or death (n = 1; unrelated to study drug). The most common treatment-related TEAEs were somnolence (17.0%), seizure (11.4%), and decreased appetite (5.7%). Patients reported serious TEAEs (n = 28, 31.8%); those reported in ≥3% of patients were seizure (n = 6), pneumonia (n = 5), acute respiratory failure (n = 3), aspiration pneumonia (n = 3), and dehydration (n = 3). SIGNIFICANCE: Sustained reductions in MMSF at 2 years in the OLE support the efficacy of ganaxolone in seizures associated with CDD. Safety findings in the OLE were consistent with the double-blind phase.

Epileptic spasms in CDKL5 deficiency disorder: Delayed treatment and poor response to first-line therapies.

OBJECTIVE: We aimed to assess the treatment response of infantile-onset epileptic spasms (ES) in CDKL5 deficiency disorder (CDD) vs other etiologies. METHODS: We evaluated patients with ES from the CDKL5 Centers of Excellence and the National Infantile Spasms Consortium (NISC), with onset from 2 months to 2 years, treated with adrenocorticotropic hormone (ACTH), oral corticosteroids, vigabatrin, and/or the ketogenic diet. We excluded children with tuberous sclerosis complex, trisomy 21, or unknown etiology with normal development because of known differential treatment responses. We compared the two cohorts for time to treatment and ES remission at 14 days and 3 months. RESULTS: We evaluated 59 individuals with CDD (79% female, median ES onset 6 months) and 232 individuals from the NISC database (46% female, median onset 7 months). In the CDD cohort, seizures prior to ES were common (88%), and hypsarrhythmia and its variants were present at ES onset in 34%. Initial treatment with ACTH, oral corticosteroids, or vigabatrin started within 1 month of ES onset in 27 of 59 (46%) of the CDD cohort and 182 of 232 (78%) of the NISC cohort (p < .0001). Fourteen-day clinical remission of ES was lower for the CDD group (26%, 7/27) than for the NISC cohort (58%, 106/182, p = .0002). Sustained ES remission at 3 months occurred in 1 of 27 (4%) of CDD patients vs 96 of 182 (53%) of the NISC cohort (p < .0001). Comparable results were observed with longer lead time (≥1 month) or prior treatment. Ketogenic diet, used within 3 months of ES onset, resulted in ES remission at 1 month, sustained at 3 months, in at least 2 of 13 (15%) individuals with CDD. SIGNIFICANCE: Compared to the broad group of infants with ES, children with ES in the setting of CDD often experience longer lead time to treatment and respond poorly to standard treatments. Development of alternative treatments for ES in CDD is needed.

Automated preprocessing and phase-amplitude coupling analysis of scalp EEG discriminates infantile spasms from controls during wakefulness.

OBJECTIVE: Delta-gamma phase-amplitude coupling in EEG is useful for localizing epileptic sources and to evaluate severity in children with infantile spasms. We (1) develop an automated EEG preprocessing pipeline to clean data using artifact subspace reconstruction (ASR) and independent component (IC) analysis (ICA) and (2) evaluate delta-gamma modulation index (MI) as a method to distinguish children with epileptic spasms (cases) from normal controls during sleep and awake. METHODS: Using 400 scalp EEG datasets (200 sleep, 200 awake) from 100 subjects, we calculated MI after applying high-pass and line-noise filters (Clean 0), and after ASR followed by either conservative (Clean 1) or stringent (Clean 2) artifactual IC rejection. Classification of cases and controls using MI was evaluated with Receiver Operating Characteristics (ROC) to obtain area under curve (AUC). RESULTS: The artifact rejection algorithm reduced raw signal variance by 29-45% and 38-60% for Clean 1 and Clean 2, respectively. MI derived from sleep data, with or without preprocessing, robustly classified the groups (all AUC > 0.98). In contrast, group classification using MI derived from awake data was successful only after Clean 2 (AUC = 0.85). CONCLUSIONS: We have developed an automated EEG preprocessing pipeline to perform artifact rejection and quantify delta-gamma modulation index.

Potential induction of epileptic spasms by nonselective voltage-gated sodium channel blockade: Interaction with etiology.

PURPOSE: Epileptic spasms are often preceded by focal (or multifocal) seizures. Based on a series of case reports suggesting that carbamazepine and oxcarbazepine may induce epileptic spasms, we set out to rigorously evaluate the potential association between exposure to voltage-gated sodium channel blockade and latency to epileptic spasms. METHODS: We identified 50 cases (children with focal seizures and evolution to epileptic spasms) and 50 controls (children with focal seizures without evolution to epileptic spasms). For each patient, we reviewed all sequential neurology encounters between onset of epilepsy and emergence of epileptic spasms. For each encounter we recorded seizure-frequency and all anti-seizure therapy exposures. Using multivariable Cox proportional hazards regression, we evaluated the association between voltage-gated sodium channel exposure (carbamazepine, oxcarbazepine, lacosamide, or phenytoin) and latency to epileptic spasms onset, with adjustment for etiology and seizure-frequency. RESULTS: Latency to epileptic spasms onset was independently associated with exposure to sodium channel blockade (hazard ratio = 2.4; 95% CI 1.1-5.2; P = 0.03) and high-risk etiology (hazard ratio = 2.8; 95% CI 1.5-5.1; P = 0.001). With assessment for interaction between sodium channel blockade and etiology, we identified an estimated 7-fold increased risk of epileptic spasms with the combination of sodium channel blockade and high-risk etiology (hazard ratio = 7.0, 95% CI 2.5-19.8; P < 0.001). CONCLUSION: This study suggests that voltage-gated sodium channel blockade may induce epileptic spasms among children at risk on the basis of etiology. Further study is warranted to replicate these findings, ascertain possible drug- and dose-specific risks, and identify potential mechanisms of harm.

Limited efficacy of zonisamide in the treatment of refractory infantile spasms.

A series of relatively small studies collectively suggest that zonisamide may be effective in the treatment of infantile spasms. Using a large single-center cohort of children with infantile spasms, we set out to evaluate the efficacy and safety of zonisamide. We retrospectively identified all patients with infantile spasms who were treated with zonisamide at our center. For each patient, we recorded dates of birth, infantile spasms onset, response (if any), and most recent follow-up. To quantify zonisamide exposure, we recorded daily dosage and patient weight at each sequential encounter so as to allow calculation of peak and weighted-average weight-based dosage. We identified 87 children who were treated with zonisamide, of whom 78 had previously been treated with hormonal therapy or vigabatrin. Peak and weighted-average zonisamide dosage were 7.1 (interquartile range 3.6, 10.2) and 5.4 (interquartile range 3.0, 8.9) mg/kg/day, respectively. Whereas five (6%) patients exhibited resolution of epileptic spasms, only two (2%) patients exhibited video-EEG confirmed resolution of both epileptic spasms and hypsarrhythmia (electroclinical response). Importantly, both electroclinical responders had not previously been treated with hormonal therapy or vigabatrin; in contrast, none of the 78 children with prior failure of hormonal therapy or vigabatrin subsequently responded to zonisamide. Zonisamide was well tolerated, and there were no deaths. This study suggests that zonisamide exhibits favorable tolerability but very limited efficacy among patients who do not respond to first-line therapy.

Felbamate in the treatment of refractory epileptic spasms.

Several small case series provide conflicting impressions of the efficacy of felbamate for treatment of epileptic spasms. Using a large single-center cohort of children with epileptic spasms, we retrospectively evaluated the efficacy and safety of felbamate. We identified all patients with video-EEG confirmed epileptic spasms who were treated with felbamate at our center. We quantified felbamate exposure by calculating peak and weighted-average weight-based dose. Clinical response was defined as resolution of epileptic spasms for at least 28 days, beginning not more than 3 months after felbamate initiation. Electroclinical response was defined as clinical response accompanied by overnight video-EEG demonstrating freedom from epileptic spasms and hypsarrhythmia. Among a cohort of 476 infants, we identified 62 children who were treated with felbamate, of whom 58 had previously failed treatment with hormonal therapy or vigabatrin. Median peak and weighted-average felbamate dosages were 47 and 40 mg/kg/day, respectively. Five (8%) children were classified as clinical responders and two (3%) children were classified as electroclinical responders. Among 17 patients with latency from epileptic spasms onset to felbamate initiation of less than 12 months, we observed 4 (24%) clinical responders. This study suggests that felbamate may be efficacious for treatment of epileptic spasms and that further rigorous study is warranted.

Prospective observational study: Fast ripple localization delineates the epileptogenic zone.

OBJECTIVE: To investigate spatial correlation between interictal HFOs and neuroimaging abnormalities, and to determine if complete removal of prospectively identified interictal HFOs correlates with post-surgical seizure-freedom. METHODS: Interictal fast ripples (FRs: 250-500 Hz) in 19 consecutive children with pharmacoresistant focal epilepsy who underwent extra-operative electrocorticography (ECoG) recording were prospectively analyzed. The interictal FRs were sampled at 2000 Hz and were visually identified during 10 min of slow wave sleep. Interictal FRs, MRI and FDG-PET were delineated on patient-specific reconstructed three-dimensional brain MRI. RESULTS: Interictal FRs were observed in all patients except one. Thirteen out of 18 patients (72%) exhibited FRs beyond the extent of neuroimaging abnormalities. Fifteen of 19 children underwent resective surgery, and survival analysis with log-rank test demonstrated that complete resection of cortical sites showing interictal FRs correlated with longer post-operative seizure-freedom (p < 0.01). Complete resection of seizure onset zones (SOZ) also correlated with longer post-operative seizure-freedom (p = 0.01), yet complete resection of neuroimaging abnormalities did not (p = 0.43). CONCLUSIONS: Prospective visual analysis of interictal FRs was feasible, and it seemed to accurately localize epileptogenic zones. SIGNIFICANCE: Topological extent of epileptogenic region may exceed what is discernible by multimodal neuroimaging.

Very-High-Dose Prednisolone Before ACTH for Treatment of Infantile Spasms: Evaluation of a Standardized Protocol.

BACKGROUND: There is ongoing debate regarding the comparative effectiveness of adrenocorticotropic hormone and prednisolone in the treatment of infantile spasms. With a large cohort and extended follow-up, we set out to evaluate a protocol in which adrenocorticotropic hormone is reserved for prednisolone nonresponders. METHODS: The following standardized hormonal therapy protocol was adopted. Patients initially receive prednisolone (8 mg/kg/day [maximum 60 mg/day], divided in three daily doses for 14 days). Prednisolone responders taper it over 14 days, whereas prednisolone nonresponders immediately transition to natural adrenocorticotropic hormone (150 U/m2/day, divided in two daily doses for 14 days). We evaluated short-term response, defined as video-electroenecphaloagraphy-confirmed resolution of both epileptic spasms and hypsarrhythmia on day 14, without relapse for 28 additional days. We then evaluated long-term relapse and calculated the rates of sustained response at six, 12, and 18 months. RESULTS: We identified 102 children with infantile spasms who were treated with prednisolone. Prior exposure to hormonal therapy and vigabatrin was observed among 12% and 35% of patients, respectively. Sixty (59%) patients responded to prednisolone, and 13 (33%) prednisolone nonresponders then responded to adrenocorticotropic hormone. Cumulative response to prednisolone and adrenocorticotropic hormone (if needed) was higher among treatment-naive patients (84%) than among patients with prior exposure to first-line treatment (51%), with P < 0.001. Relapse was relatively common among all subgroups. CONCLUSION: Short-term response to prednisolone was favorable and higher among treatment-naive patients. These data suggest that prednisolone is a reasonable approach to initial therapy and that adrenocorticotropic hormone exhibits substantial efficacy after prednisolone failure.

Successful use of pure cannabidiol for the treatment of super-refractory status epilepticus.

We present the case of a child with long-standing, super-refractory status epilepticus (SRSE) who manifested prompt and complete resolution of SRSE upon exposure to pure cannabidiol. SRSE emerged in the context of remote suspected encephalitis with previously well-controlled epilepsy. We discuss the extent to which response may be specifically attributed to cannabidiol, with consideration and discussion of multiple potential drug-drug interactions. Based on this case, we propose that adjunctive cannabidiol be considered in the treatment of SRSE.

Prevention of infantile spasms relapse: Zonisamide and topiramate provide no benefit.

OBJECTIVE: There is scant evidence to guide the management of infantile spasms after successful response to initial therapies. There is significant risk of relapse, largely because effective pharmacologic treatments cannot be continued long term because of concern for significant adverse events. Zonisamide (ZNS) and topiramate (TPM) are commonly used to prevent relapse, and the purpose of this study was to specifically evaluate the efficacy of ZNS and TPM as agents for secondary prevention of infantile spasms. METHODS: Patients with video-electroencephalography (EEG) confirmed resolution of infantile spasms were retrospectively identified. Relevant clinical data were systematically collected, including lead time from onset of spasms to successful treatment response, etiology of infantile spasms, number of treatment failures prior to response, timing of relapse, and detailed exposure data for ZNS and TPM. RESULTS: We identified 106 patients with response to hormonal therapy (n = 58), vigabatrin (n = 25), or surgery (n = 23). To prevent relapse of infantile spasms, 37 patients received ZNS, 34 received TPM, 3 received both ZNS and TPM, and 38 patients received neither ZNS nor TPM. There were 44 relapses, occurring a median of 6.9 (3.2-10.8) months after initial response. Time to relapse was not affected by treatment with ZNS or TPM. Relapse was less likely among patients who were older (hazard ratio 0.97 [per month], p = 0.036) and those who responded to surgical resection (hazard ratio = 0.28, p = 0.017). Of note, we identified a relatively refractory cohort with multiple treatment failures and long lead time to initial response. SIGNIFICANCE: In this refractory cohort, neither ZNS nor TPM was successful in preventing relapse of infantile spasms, despite relatively high dosages. At this time, aside from surgical resection in eligible candidates, there is no known treatment that is efficacious in the prevention of relapse of infantile spasms.

Correlation of health-related quality of life in children with inflammatory bowel disease, their parents, and physician as measured by a visual analog scale.

BACKGROUND AND AIMS: Inflammatory bowel disease has been shown to affect children's health-related quality of life (HRQOL) through the use of lengthy questionnaires. We examined whether a pediatric patient's HRQOL, measured by a rapid visual analog scale ("feeling thermometer"), correlates with the perceptions of the HRQOL as determined by the patient's pediatric gastroenterologist and parent(s). Additionally, we attempted to determine whether the HRQOL correlates with the patient's disease activity as determined by validated activity indices. METHODS: A cross-sectional study of pediatric patients (ages 7-21 years) who were diagnosed as having Crohn disease, ulcerative colitis, or indeterminate colitis was conducted from January 2011 to May 2011. Each participant (patient, parent(s), and treating pediatric gastroenterologist) completed feeling thermometers to determine the symptom burden as well as therapeutic burden of the patient. The parent(s) and doctor were blinded to the patient's results. Pediatric Ulcerative Colitis Activity Index or a Short Pediatric Crohn Disease Activity Index (S-PCDAI) was calculated. Correlations between the participant's perceived burdens as well as their calculated disease activity were determined. RESULTS: Sixty-seven children and their families participated, resulting in 101 visits. Patients had a mean age of 15.0 years, and there were 38 boys. There was a strong significant correlation between the patient's perceived symptom burden and that of the parent's (ρ 0.59, P < 0.001) and physician (ρ 0.48, P < 0.001). Similarly, there was a strong significant correlation between patient's perceived treatment burden and that of the parent treatment burden (ρ 0.49, P < 0.001) and, to a lesser degree, the physician (ρ 0.29, P < 0.003). The correlation coefficient was strongest between the physician's perception of the patient's symptom burden against the standard disease activity indices Pediatric Ulcerative Colitis Activity Index (ρ 0.69, P < 0.001) and Short Pediatric Crohn Disease Activity Index (ρ 0.65, P < 0.001). CONCLUSIONS: The patient's HRQOL was highly correlated to both the physician's and parent's perceptions as well as their disease activity. The feeling thermometer is a quick, easy-to-use, visual analog scale that can be implemented in everyday practice to measure a pediatric patient's HRQOL.