Attenuated heart-brain integration predicts functional non-epileptic seizures. Issue 9 (12th August 2022)

• Record Type: Journal Article
• Authors: Elkommos, Samia; Martin-Lopez, David; Koreki, Akihiro; Jolliffe, Claire; Mula, Marco; Critch-ley, Hugo; Edwards, Mark; Garfinkel, Sarah; Richardson, Mark P; Yogarajah, Mahinda
• Is Part Of: Journal of neurology, neurosurgery and psychiatry. Volume 93:Issue 9(2022)
• Page Start: e2
• Publication Date: 2022-08-12
• Subjects: Neurology -- Periodicals; Nervous system -- Surgery -- Periodicals; Psychiatry -- Periodicals; 616.8
• DOI: 10.1136/jnnp-2022-abn2.34
• Languages: English
• ISSNs: 0022-3050

Abstract

Abstract : Background: Patients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation encompasses a feeling of disembodiment, putatively caused by reduced afferent visceral mapping, that is, changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an electroencephalographic (EEG) index of synchronised neural responses to individual heart- beats, and a marker of interoceptive representation. HEP amplitude is reported to be reduced in dep- ersonalisation-derealisation disorder. Purpose: To assess whether alterations in interoceptive processing indexed by the HEP occur prior to FSs, and compare this with epileptic seizures (ES). Methods: HEP amplitudes were calculated from EEG during video-EEG monitoring in 25 patients with FS and 19 patients with ES, and compared between interictal and preictal states. Results: The FS group demonstrated a significant reduction in HEP amplitude between interictal and preictal states at F8 (rB=0.612, p=0.006) and C4 (rB=0.600, p=0.007). No differences in HEP amplitude were found between interictal and preictal states in the ES group. Findings were not related to heart rate, mean ECG or QRS amplitudes, which did not differ between states or groups. Conclusion: Our data support the notion that aberrant interoception underpins disembodiment prior to dissociative FS. Changes in HEP amplitude may reflect a neurophysiological biomarker of FS.