Abstracts

Rationale: Seizures are one of the most common neurological causes of Emergency Department (ED) visits with almost 1 million ED visits per year in the United States alone. Many of these patients undergo emergency neuroimaging, mostly head computed tomography (CT). An evidence-based review by the American Academy of Neurology (AAN) in 1996 with reassessment in 2007 showed some evidence of usefulness of ED neuroimaging in new onset seizures as it led to acute change in the management. On the other hand, there was lack of evidence of its usefulness in patients with chronic epilepsy. The aim of this retrospective study was to review the clinical presentation of patients with chronic epilepsy who presented to the ED with breakthrough seizures to analyze the impact of neuroimaging on their acute management. Methods: We reviewed the medical records of patients age 18 years and above who presented to Upstate Medical University Hospital ED with a seizure during the period of January 1, 2017, to December 31, 2018. Inclusion criteria were an established diagnosis of epilepsy with being on at least one antiepileptic medication. For each patient, we reviewed the clinical history and presentation, level of antiepileptic drugs obtained in the ED when available, possible etiology of breakthrough seizures, and whether a CT head was obtained. We then determined whether CT head in ED led to an immediate change in those patients’ care. Results: Ninety patients met the inclusion criteria including 55 (61.1%) male and 35 (38.9%) female. The mean age was 37.7 (+/-14.7) years. A total of 39 patients (43.3%) had a neuroimaging during the ED visit (CT group) whereas the rest did not (non-CT group; n=51, 56.7%). Breakdown of etiology of epilepsy in each group, based on their previous records, is shown in Figure 1. The suspected reason for breakthrough seizure was not statistically different between the CT and non-CT groups (p=0.93): non-compliance comprised 53.8% in CT group and 47.1% in non-CT group. Other suspected reasons were a change in antiepileptic medications by health care professionals in 7.7% and 9.8%; other triggering factors such as sleep deprivation in 23.1% and 25.5%; and unknown reasons in 15.4% and 17.6% in the respective 2 groups. 7 patients in the CT group (18%) and 2 (3.9%) of patients in the non-CT group had a focal neurological finding similar to their baseline exam in their records and rest of the patients had a non-focal exam. In the CT group, the management was impacted by the CT findings in only 3 out of 4 patients with a known brain tumor, showing some changes such as increased peri-tumor edema, which required administration of steroids, for example. The management of no other patient was impacted by the results of imaging. Conclusions: In patients with chronic epilepsy and breakthrough seizures emergency neuroimaging can be helpful in only a small percentage of patients with a particular known structural abnormality that could potentially show some changes over time, such as brain tumor in our study, or vascular abnormalities. Otherwise, non-selective use of ED neuroimaging in patients with no new neurological findings, especially in those with a known suspected cause of breakthrough seizure, is of a very low yield. Funding: No funding