Mitchell, Wendy G.

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.

Objective: In a randomized trial, we aimed to evaluate the efficacy of cosyntropin injectable suspension, 1 mg/mL, compared to vigabatrin for infantile spasms syndrome. An additional arm was included to assess the efficacy of combination therapy (cosyntropin and vigabatrin) compared with cosyntropin monotherapy. Methods: Children (2 months to 2 years) with new-onset infantile spasms syndrome and hypsarhythmia were randomized into 3 arms: cosyntropin, vigabatrin, and cosyntropin and vigabatrin combined. Daily seizures and adverse events were recorded, and EEG was repeated at day 14 to assess for resolution of hypsarhythmia. The primary outcome measure was the composite of resolution of hypsarhythmia and absence of clinical spasms at day 14. Fisher exact test was used to compare outcomes. Results: 37 children were enrolled and 34 were included in the final efficacy analysis (1 withdrew prior to treatment and 2 did not return seizure diaries). Resolution of both hypsarhythmia and clinical spasms was achieved in in 9 of 12 participants (75%) treated with cosyntropin, 1/9 (11%) vigabatrin, and 5/13 (38%) cosyntropin and vigabatrin combined. The primary comparison of cosyntropin versus vigabatrin was significant (64% [95% confidence interval 21, 82], P < .01). Adverse events were reported in all 3 treatment arms: 31 (86%) had an adverse event, 7 (19%) had a serious adverse event, and 15 (42%) had an adverse event of special interest with no difference between treatment arms. Significance: This randomized trial was underpowered because of incomplete enrollment, yet it demonstrated that cosyntropin was more effective for short-term outcomes than vigabatrin as initial treatment for infantile spasms.

Summary Objective To prospectively evaluate the etiology of new‐onset infantile spasms and evaluate the yield of genetic and metabolic investigations in those without obvious cause after initial clinical evaluation and magnetic resonance imaging ( MRI ). Methods Twenty‐one U.S. pediatric epilepsy centers prospectively enrolled infants with newly diagnosed West syndrome in a central database. Etiology and investigations performed within 3 months of diagnosis were documented. Results From June 2012 to June 2014, a total of 251 infants were enrolled (53% male). A cause was identified in 161 (64.4%) of 250 cases (genetic,14.4%; genetic‐structural, 10.0%; structural‐congenital, 10.8%; structural‐acquired, 22.4%; metabolic, 4.8%; and infectious, 2.0%). An obvious cause was found after initial clinical assessment (history and physical examination) and/or MRI in 138 of 161, whereas further genetic and metabolic studies were revealing in another 23 cases. Of 112 subjects without an obvious cause after initial evaluation and MRI , 81 (72.3%) had undergone genetic testing, which showed a causal abnormality in 23.5% and a variant of unknown significance in 14.8%. Although metabolic studies were done in the majority (serum, 79.5%; urine, 69.6%; and cerebrospinal fluid [ CSF ], 38.4%), these revealed an etiology in only five cases (4.5%). No correlation was found between type of health insurance (public vs. private) and either genetic or metabolic testing. Significance Clinical evaluation and MRI provide a specific diagnosis in 55% of children presenting with West syndrome. We propose that a cost‐effective workup for those without obvious cause after initial clinical evaluation and MRI includes an array comparative genomic hybridization ( aCGH ) followed by an epilepsy gene panel if the microarray is not definitive, serum lactate, serum amino acids, and urine organic acids.