Usefulness of ocular compression during electroencephalography in distinguishing breath-holding spells and syncope from epileptic seizures.

Episodes of syncope or breath-holding spells are often misdiagnosed as epileptic events. The purpose of this study was to assess the usefulness of an electroencephalogram (EEG) with ocular compression to distinguish breath-holding spells and syncope from epileptic seizures. A retrospective analysis was performed on the EEG records of all children on whom ocular compression was performed from 2000 to 2003. Data from 116 patients with a clinical diagnosis consistent with either syncope or breath-holding spells were compared with a group of 46 patients with epilepsy. The RR interval during ocular compression was significantly higher in syncope patients compared with patients with epilepsy (P < .005). Using 2 seconds of asystole as the cutoff, the sensitivity of ocular compression was 26%, with 100% specificity. The change in RR interval from baseline to ocular compression also distinguished patients with breath-holding spells and syncope from patients with epilepsy. Even a small increase of 0.5 seconds in the RR interval demonstrated a sensitivity of 46%, with a specificity of 98%. Ocular compression performed during an EEG is useful in distinguishing patients with breath-holding spells and syncope from those with epileptic seizures. A requirement of a 2-second period of asystole with ocular compression excludes many patients. Our data indicate that an RR interval increase of 0.5 seconds over baseline identifies additional patients with increased vagal tone. Prompt and accurate diagnosis of the etiology of loss of consciousness might preclude the need for further extensive and expensive evaluation and reduce patient and parental distress.