Abstracts

Rationale: Children with ESES/CSWS (Continuous Spikes and Waves during Slow wave sleep) may have substantial cognitive impairments, but little is known about specific diagnoses and medical correlates in predicting outcome. The purpose of the current study is to investigate cognitive functioning in a sample of children with ESES/CSWS. Methods: 25 children (aged 2-14 years) received neuropsychological evaluation between 2008 and 2018 as part of their clinical care; all were diagnosed with ESES/CSWS (spike burden >80%) by their treating epileptologist. Clinical characteristics and cognitive findings were documented. A subset (n=12) of children were followed longitudinally. Results: Nearly half had abnormal MRI findings (48%), with 9 (36%) showing evidence of perinatal stroke, 1 (4%) child demonstrating schizencephaly, 1 child (4%) with an arachnoid cyst, and another (4%) with hyperintensities in the basal ganglia. Nearly all children were on antiepileptic medications at time of assessment (84%), with the most common medications being valproic acid (36%) and clobazam (24%), followed by sulthiame (16%) and levetiracetam (12%), with only 1 child each (4%) on carbamazepine, clobazam, ethosuximide, gabapentin, IVIG and ketogenic diet. Six children were on multiple antiepileptic medications.At initial assessment, mean full scale IQ (FSIQ) was 78.96 (19.34). 32% of children had FSIQ in the “very low” range (FSIQ=70-79) whereas 20% had FSIQ in the range associated with intellectual disability (FSIQ moderate effect size). Similarly, children with ESES/CSWS and perinatal stroke (n=9) showed lower intellectual functioning (FSIQ=70.33 vs. 83.81; Cohen’s d=0.71, moderate effect size) than those without evidence of stroke. Of the 13 children with normal MRI and ESES/CSWS, 8 children (62%) had average FSIQ (FSIQ >80).The most common cognitive diagnoses rendered were 1) Intellectual disability (n=5, 20%), Attention Deficit/Hyperactivity Disorder (ADHD; n=15, 60%), Speech/Language Disorder (N=4, 16%), or a Learning Disability (n=1, 4%). Sixteen children (64%) were receiving special education services.Of the 12 children followed longitudinally, four (33%) showed significant decline in overall intellectual functioning (i.e., one standard deviation [15 points] or greater decline in FSIQ) over a period =24 months. Of those showing decline, three children (75%) had abnormal MRI. 42% of children (5/12) demonstrated stable FSIQ over a follow-up period ranging from 2-7 years, with 3 children maintaining average FSIQ over the same period. Conclusions: This investigation highlights the importance of neuropsychological assessment in children with ESES/CSWS, as intellectual disability, ADHD, and other cognitive deficits are common. Moreover, as this population is prone to decline, longitudinal follow-up is warranted such that appropriate medical interventions and educational supports can be provided. Funding: Not applicable