Abstracts

Rationale: Inpatient video EEG monitoring (EMU) is considered the gold standard for spell classification. In cases where the differential diagnosis included syncope or autonomic dysfunction, cardiac tilt table testing can assist in determining in the underlying diagnosis. Concurrent continuous video EEG monitoring (vEEG) allows assessment for potential epilepsy. We describe our experience with cardiac tilt table testing during EMU admission as a method of provoking spells and determining the underlying diagnosis. Methods: We retrospectively identified admission with cardiac tilt table testing from our EMU database. EEG records and medical charts were reviewed to identify the diagnostic yield of testing and findings during the EMU admission. Results: Between 2012 and 2015, a total of 944 patients were admitted to the EMU. 42 (4.5%) of these patients had a cardiac tilt table test during the admission. 28 (67%) of these patient were female. 13 (31%) of the patients were 50 years of age or older. 36 (86%) patients reported symptoms during the study, 16 of which had a normal cardiac tilt table test and normal EEG suggesting nonepileptic behavioral events. In 2 patients the cardiac tilt table test was normal, but the EEG showed diffuse slowing in association with symptoms. The cardiac tilt was abnormal in 19 (45%). The tilt table diagnosis was vasovagal syncope in 4 patients, neurocardiogenic syncope in 4 patients, orthostatic intolerance/ hypotension in 5 patients and postural orthostatic tachycardia syndrome (POTS) in 6 patients. 22 (52%) patients had events during vEEG as well as during the tilt test; 14 (33%) had events during tilt only. In 23 (55%) of the patients the tilt table test was crucial in determining the final diagnosis. As a result, 7 (17%) of these patients had antiepileptic medications discontinued upon discharge. 4 (9.5%) patients were discharged with a dual diagnosis of syncope and epilepsy. Conclusions: In patients with indeterminate spells, or for whom the differential diagnosis includes convulsive syncope, tilt table testing during EMU can increase the diagnostic yield. In our selected population of patients that underwent tilt table testing, results determined the discharge diagnosis. The diagnoses included vasovagal syncope, orthostatic hypotension and POTS. These results also led to management decisions, including discontinuation of unnecessary antiepileptic therapy. We identified 4 patients with both epilepsy and syncope or autonomic dysfunction. Funding: None