Abstracts

Rationale: Infantile spasms (IS)—an age specific developmental and epileptic encephalopathy—are the largest single subgroup of infantile onset epilepsy. Following a diagnosis of IS, patients undergo treatment with high dose hormonal therapy or vigabatrin. This places them at risk for side effects from these medications. Additionally they need close clinical and EEG follow-up. There are no data on how often these infants are hospitalized in the short term following a diagnosis of IS. The purpose of this retrospective study was to characterize the rates of inpatient readmissions, the most common reasons for readmissions, and to identify the patient and treatment-related factors associated with increased readmission risk.

Methods: We conducted a retrospective review of charts for patients with new onset IS (between age 2-24 months) born 2017-2019. We reviewed all patients with IS onset who were either diagnosed at our center or referred to and followed at our center, for evaluation and treatment of IS. Data collected included demographics, clinical IS characteristics including age at onset, treatment, delays and seizures prior to IS onset, hospital admissions following IS onset (entire follow-up period), and reasons for admission. We compared patients with multiple readmissions (≥5 versus < 5 readmissions) with regards to various patient demographics (such as age, sex), insurance status, and clinical characteristics. Comparisons of percentages and medians between the 2 groups were assessed with the Fisher’s exact test, chi-square test, and Pearson correlation coefficient

Results: We examined readmissions data on 51 (41% female) consecutive patients born between 2017-2019 and diagnosed with IS between 2-24 months of age and followed up through June 2021. Median age at onset was 7 months and etiology was known in 76%. At a median follow-up of 2.4 years, 82% had at least 1 hospitalization, 49% had less than 3 admissions, and 31% had 5 or more admissions following IS diagnosis. Patients who were readmitted ≥5 times were more likely to have seizures prior to IS onset, p=0.036. There was no association between other clinical characteristics such as age at IS onset, developmental delay prior to IS onset, etiology, number of first line IS Treatments used or insurance type (public versus private) and multiple (≥5) readmissions.

Scheduled readmissions were noted in 58% of the patients with first readmission and 48% of patients undergoing 4th readmission. Reasons for scheduled readmissions were for EEG follow-up in seizure free patients, assess response to first line treatments, ketogenic diet initiation, G tube placement or other surgery and pre-surgical evaluation. Unscheduled admissions were mostly for characterization of new suspicious events or for seizure exacerbation. Other reasons included respiratory and infectious illness and new diagnosis of tumor.

Conclusions: Repeated hospitalization (≥5) was noted in a third of infants in the first 2 years of follow-up with new onset IS. History seizures prior to IS onset appears to be a risk for recurrent readmissions. Our study provides some information on hospital utilization in infants with new onset IS to help counsel families.

Funding: Please list any funding that was received in support of this abstract.: None.