Abstracts

Rationale: Tuberous sclerosis complex (TSC) is primarily a neurological disorder with multi-system involvement. Common neurological sequelae include epilepsy and impaired development. Children with TSC are at high risk for specific seizure types including epileptic spasms (ES) which may further impact developmental outcomes. Several recent trials – EPISTOP and PReVENT – have demonstrated a benefit to starting TSC-specific, anti-seizure medications (ASMs) prior to clinical seizures by utilizing electroencephalograms (EEGs) in determining seizure risk. Despite these results, formal guidelines on initiation and frequency of screening EEGs, and study duration, have not been defined.

Methods: We present our center’s experience through a retrospective chart review. Using inbuilt tools in the electronic medical record (EMR) we identified patients under the age of 5 with a diagnosis of TSC by genetic or clinical criteria. We included patients identified as local to our center, defined as a primary address found within a 50-mile radius of Houston, Texas at the time of the patient’s birth. Descriptive characteristics were obtained, such as timing of first EEG (neonatal EEG, within 2 weeks of age, versus standard EEG, completed after 2 weeks of age), whether preventative medication was initiated, and the presence of epilepsy or ES at last follow up.

Results: Sixty-three total patients were identified, 25 of which met inclusion criteria. Eleven patients (44%) got a neonatal EEG. Eight of the 11 (72%) had some abnormality found including three with subclinical seizures (27%), all of which were started on ASMs. Of the 14 patients without neonatal EEG, 13 patients had one or more EEGs. The median time to first EEG was 7.6 months (min-max, 0.7-35 mo); 11 of the 13 (85%) were abnormal and three patients (27%) were found to have active seizures on their first EEG. Two of the 11 patients from the neonatal EEG cohort passed away (arrhythmia, status epilepticus). Of the remaining 9, 6 (66%) were on ASMs (median start age, 1.43 mo; range, 1 d – 7 mo) compared to 9 (64%) from the standard EEG population (6.7 mo; range, 21 d – 21 mo). Two patients (18%) from the neonatal EEG group developed ES compared to 5 (36%) from the standard EEG group. At the last documented follow up visits (neonatal cohort: age 1.3-38 mo; late EEG cohort: age 3.87-44 mo) 8/9 vs 12/14 patients were seizure free (89% vs. 86%) and 8/9 vs. 9/14 (89% vs. 64%) had normal development for age.

Conclusions: The trends in this single-center cohort mirror those that have been previously reported by larger clinical trials, which did not differentiate timing of the first EEGs between the early neonatal versus early infancy time periods. Though interpretation of our results is limited by the retrospective nature and heterogeneity within patients with TSC, our data suggests continuous EEG prior to 2 weeks of age may reduce time to starting a preventative medication but further study is needed to determine whether this may result in improved long-term developmental outcomes and seizure control.

Funding: None