Abstracts

Rationale: Infantile spasm (IS) is a special seizure (sz) type seen in West Syndrome (WS). WS is an age specific intractable epileptic encephalopathy characterized by IS, hypsarrhythmia, and developmental regression. ACTH and Vigabatrin are the FDA approved therapies for IS. Hypsarrhythmia is the classic interictal EEG pattern seen with IS. The objective of this retrospective study is to analyze EEG findings following the first treatment in children presenting with new onset infantile spams and correlate with the outcome. Methods: After IRB approval, we extracted details form the Children’s Healthcare of Atlanta Infantile spasm database from June 2015 to June 2017. Among the 75 patients, after excluding deceased patients, 71 patients were identified. For analysis, 2 main groups were created. Group A (A): Patients who presented with infantile spasm as their first sz type (56) and Group B (B): Patients with previous h/o epilepsy and presented with infantile spasms (15). Spasm details, pre and first post treatment EEG findings were analyzed. Results: Out of 71 patients, 30/56 were males (A) and 9/15 males (B). Mean age of onset of spasms was 6 months (A) and 4 months (B). Mean age at initial diagnosis is 8 months (A) and 6 months (B). In (A) patients started treatment within 1.5 days from diagnosis compared to 4 days (B). Median time for cessation of spasm is 4 days (A) and 7 days (B). Compared to 80 % in (B) only 20 % (A) had different sz types. As first line treatment, ACTH was used 63% (A), 27% (B); vigabatrin in 12.5 % (A), 33% (B); Prednisolone in 18 %(A) and 40% (B). 32/56 (A) had remission of spasm following first medication compared to 3/15(B). Second medication was required in 73 % (A) and 54 %(B). Metabolic panel, CMA and epilepsy gene panel was done in 29, 35, 6 patients (A) and 7, 7, 2 (B). Normal brain MRI was seen in 48%. Median age of first EEG is 6 months (A) and 5months (B). Prolonged (> 4 hours) video EEG study was done in 60 %( B) and 39 %( A). First EEG showed Hypsarrhythmia in 68% (A) and 33 %(B). Modified hypsarrhythmia seen 13 %( B) and 6.5 % (A). Median time interval between the pre and first post treatment EEG was 14-16 days.  In first post treatment EEG: Normal awake BG was seen 42% (A) and 7 %(B). 24 % (A) continued to have hypsarrhythmia compared to 46 %(B). In (A) epileptiform discharges are seen at temporal11%,  posterior quadrant 19 % and other location 8 % compared to 47% , 27% and 20% (B). Paroxysmal fast activity, episodic background attenuation and silent electrographic seizures are significant in (B) and also in patients who required second medication to control the spasms in (A). Good sz outcome at 6 months following first post treatment EEG was seen in 86 % (A) and 33 % (B). Conclusions: In our cohort of IS patients, most of them from both groups had classic hypsarrhythmia in their first EEG. Following first line treatment, follow up EEG showed significant findings in patients who have previous history of epilepsy and also in patients who required second medication to attain clinical remission. Funding: none