Abstracts

Rationale: Children with tuberous sclerosis complex (TSC) carry a significant seizure burden due to cortical tubers and subependymal giant cell astrocytomas (SEGA). The timing and indication for surgery remains a clinical dilemma. Methods: We report 3 TSC patients  who were considered for surgery due to high seizure burden and hydrocephalus.  Results: Patient  #1 was a term newborn female in focal status epilepticus since 15 minutes of life with 50-100 daily seizures lasting up to 20 minutes. She was on topiramate, phenobarbital, lacosamide, midazolam, and pentobarbital. Burst suppression was induced but status epilepticus recurred upon weaning the drips. MRI demonstrated a large left frontoparietal giant cell astrocytoma (Figure 1).  Hemispherectomy was deferred due to the risk of high mortality and the patient’s young age. The mother decided to withdraw support on day 23. She was heterozygous for a pathogenic variant of the TSC1 gene with exon 1 deletion.Patient #2 is a 2 yo boy who presented with a large left frontal subependymal mass causing hydrocephalus soon after birth. Biopsy confirmed SEGA. A VP shunt was placed and Everolimus was started. Renal ultrasound and echocardiogram did not reveal TSC-related tumors. He was heterozygous for a pathogenic variant of the TSC2 gene with c.4928A>G; p.Asn1643Ser. He was profoundly delayed but was seizure-free until 16 months of age when he began having brief intermittent rhythmic extremity twitching. Partial resection of the SEGA was performed at age 2. Post-operatively, he developed status epilepticus and paroxysmal sympathetic hyperactivity. He is on  Keppra, Valproic acid, Gabapentin and Diazepam and has 6-8 brief tonic seizures daily. Patient #3 is an 8 yo girl with tonic clonic seizures at 5 weeks of age. MRI showed multiple cortical/ subcortical tubers and a SEGA. Renal ultrasound showed bilateral renal angiomyolipomas. Echocardiogram showed small rhabdomyomas. She had 3 seizures daily but sustained head injuries from drop attacks despite wearing a helmet. She was on Oxcarbazepine, Valproic acid, Vigabatrin, Zonisamide, and Lacosamide. Repeat brain MRI showed subependymal nodules and multiple cortical/subcortical tubers, most prominent in the right frontal lobe. There were epileptic spasms with asymmetric bilateral arm extension with head turn to the right and initial EEG change in the right frontal region. Interictally, there were focal epileptiform discharges in the right frontal and temporal regions. Ictal SPECT showed right frontal hyperperfusion. Intracranial strip electrodes placed radially on the frontal tubers did not confirm them as ictal onset-zones and the EEG changes appeared to be diffuse.  Corpus callosotomy was performed to reduce the drop attacks. At 3 months post-op, she had no recurrent drop attacks, dyscognitive or tonic clonic seizures. She continued to have myoclonic seizures every other day and is more alert and doing better at school. Conclusions: The approach to managing epilepsy in children with TSC is highly individualized. The decision to consider surgery is based on seizure burden and clinical sequelae of TSC-related brain lesions. These three cases demonstrate that surgery, in conjunction with medication management, can help decrease seizure burden and improve quality of life. Funding: None