#7223 Greater number of peri-ictal symptoms endorsed on forced-choice questioning predicts functional/dissociative seizures in patients presenting with transient loss of consciousness
Year: 2025
Type: conference-paper
Study design: Observational Study
Abstract: Background Transient loss of consciousness (TLOC) is one of the commonest neurological presentations. Over 90% of primary TLOC is due either to syncope, epileptic seizures, or functional/dissociative seizures (FDS). Obtaining a reliable patient and collateral history is key to diagnosis, but reporting of ictal experience is highly variable and dependent on clinician approach to history-taking. Previous research suggests that people with FDS (PwFDS) may be more likely to report multiple comorbidities, and also report a greater range of symptoms on review of symptoms questionnaires, than people with epilepsy. Method We prospectively recruited consecutive patients with a first presentation of TLOC to the Emergency Department, Acute Medical Unit, Cardiology or Neurology clinics at a single tertiary hospital for an 11-month period from February 2022 to January 2023. We invited patients to complete a brief self-administered online questionnaire regarding past medical history and peri-ictal symptoms, which we used to develop and validate a diagnostic algorithm for differentiating between syncope, epilepsy, and FDS; we report these results elsewhere. Here we report the value of number of historical items and peri-ictal symptoms endorsed as predictive of the diagnosis of FDS. Results We recruited 178 patients (134 syncope, 32 epilepsy, 12 FDS). People with FDS reported significantly more items of past medical history (median (IQR) 6 (4.5) for FDS; 3 (4) for epilepsy and 3 (4) for syncope; Kruskal-Wallis chi-squared = 15.474, df = 2, p <0.001), and endorsed more symptoms (12 (6.75) for FDS, 6 (4) for epilepsy, 4 (5.75) for syncope; Kruskal-Wallis chi-squared = 19.729, df = 2, p<0.001). Using total number of peri-ictal symptoms endorsed to predict FDS diagnosis yielded area under receiver-operating characteristic curve (AUC) = 0.864 (95% confidence interval 0.781–0.948); using an optimal cutoff of 9 or more symptoms reported was 91.7% sensitive and 72.9% specific for FDS. Interpretation Our results support previous research suggesting that PwFDS have higher levels of intra-ictal awareness than pwE, and that the relative dearth of ictal symptom reporting observed in response to open questioning in PwFDS may represent a deficit of recall rather than one of memory formation. Detailed history-taking can yield richer accounts of ictal subjective experience (as can other methods of interrogation under hypnosis). Symptom reporting in transient loss of consciousness is dependent upon history-taking style and expertise; further work is warranted to maximise information extracted from subjective seizure experiences.
Authors: Alistair Wardrope, Steve Goodacre, Daniel Habershon, Timothy J Heaton, Stephen J Howell, Markus Reuber
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4407111167