Diagnosing Pseudoseizures: Don't Hold Your Breath

Abstract

Postictal Breathing Pattern Distinguishes Epileptic from Nonepileptic Convulsive Seizures. Azar NJ, Tayah TF, Wang L, Song Y, Abou-Khalil BW. Epilepsia 2008;49(1):132–137. PURPOSE: To examine postictal breathing pattern in generalized convulsive nonepileptic seizures (GCNES) and generalized tonic–clonic seizures (GTCS) and evaluate this feature as a discriminating sign. METHODS: We reviewed the postictal breathing pattern seizures in 23 generalized tonic–clonic seizures in 15 consecutive patients with epilepsy and 24 convulsive nonepileptic seizures in 16 consecutive patients with pure psychogenic seizures. We also analyzed 21 frontal lobe hypermotor seizures (FLHS) in 9 patients with frontal lobe epilepsy. RESULTS: The breathing after GTCS was deep with prolonged inspiratory and expiratory phases, regular, and loud (except for two short seizures). The breathing after GCNES was characterized by increased respiratory rate or hyperpnea with short inspiratory and expiratory phases, as can be noted after exercise. The breathing was often irregular, with brief pauses. The altered breathing lasted longer after GTCS. The two groups differed significantly in loudness of postictal respiration, postictal snoring (only with GTCS), respiratory rate (faster for the GCNES group), and duration of altered breathing (longer after GTCS) (p < 0.00001 for all features). FLHS shared postictal breathing features of GCNES, but had other distinguishing features. CONCLUSIONS: The postictal breathing pattern can help differentiate generalized tonic–clonic seizures from nonepileptic psychogenic seizures with generalized motor activity and may be helpful to the practitioner obtaining a seizure history in the clinic setting or witnessing a seizure.