Tilt Table Testing with Video EEG Monitoring in the Evaluation of Patients with Unexplained Loss of Consciousness

Abstract

It is well established that convulsive movements often accompany syncopal events yet many patients with these clinical features are misdiagnosed with seizures and often referred to epilepsy centers because they are refractory to treatment with anticonvulsant medications. Tilt table testing is the gold standard for diagnosing vasodepressor syncope, but it can fail to provide clinical details that help distinguish convulsive syncope from epileptic seizures and psychogenic events. This study evaluates the diagnostic utility of the addition of video and EEG monitoring during tilt table testing for patients with refractory episodes of unexplained loss of consciousness. Retrospective analysis was performed of 40 consecutive patients who were referred to the Emory Epilepsy Center and underwent tilt table testing with concomitant video-EEG between March 1, 2007 and December 1, 2008. EEG was recorded throughout the study in addition to video recording and single channel EKG. Events were classified as vasodepressor syncope, pre-syncope, or psychogenic. Tilt combined with video EEG was diagnostic in 26/40 (65%) of patients. Vasodepressor syncope was seen in 17/40 (42.5%), 9 of which had associated involuntary movements. Three patients experienced psychogenic non-epileptic events. Antiepileptic drugs (AEDs) were being prescribed for 17 patients, 7 of which were discontinued as a result of the testing. The majority of patients (38/40) had undergone prior neurological and cardiac evaluation with routine EEG, neuroimaging and/or Holter monitoring. Patients with convulsive syncope are often misdiagnosed and treated with AEDs despite prior neurodiagnostic and cardiac evaluation. Tilt table testing with video-EEG is useful in patients with refractory episodes of unexplained loss of consciousness and can avoid expensive non-diagnostic evaluations as well as ongoing treatment with unnecessary AEDs.