Document resource
Background Differentiating between epileptic seizures (ES) and functional seizures (FS) without video evidence is a common yet challenging presentation in several healthcare environments. Often, the absence of a witnessed collateral history can make this diagnosis even more difficult.Post-ictally, ES classically lead to prolonged lethargy, confusion and headache whilst FS tend to have a much shorter recovery however in practice this may not always be clear.Case reports have anecdotally reported that individuals with FS can sometimes report a sense of relief after their seizures.1 However, this has never been assessed prospectively in a large group of individuals with FS or compared to those with ES.Objective We aimed to explore the phenomenon of a sense of relief after seizures (paradoxical relief) as a diagnostic tool for FS. We hypothesised that patients with FS may be more likely to feel a sense of relief after seizures than patients with ES.Method We prospectively asked 167 patients admitted to a tertiary video telemetry unit if they experienced paradoxical relief. The patients then underwent video telemetry, the gold standard for diagnosis of epileptic and functional seizures.Result Within this cohort of 167 patients, 82 patients had events whilst on EEG. 56 patients had FS, and 26 patients had ES. 43 out of the 56 patients with FS described paradoxical relief whereas 2 out of the 26 patients with ES described paradoxical relief. This gives the presence of paradoxical relief in FS a sensitivity of 0.77 and specificity of 0.92. The positive predictive value of presence of paradoxical relief in patients with FS was 0.96. The negative predictive value was 0.65.Some comments made by patients included:It is as if I feel earthed or fused again … whole again.’‘Sometimes it feels like it needed to happen to get my energy back’.‘This strange build up and strange taste has gone ... I am kind of glad it has happened.’Conclusion In conclusion, paradoxical relief is present in most individuals with FS but not in patients with ES. The single question of presence of paradoxical relief may be valuable in the diagnosis of FS, especially where further investigation or collateral history is not available. The presence of paradoxical relief in patients with FS may be useful to further our understanding of the mechanisms underlying FS.Reference Stone J, Carson AJ. The unbearable lightheadedness of seizing: wilful submission to dissociative (non-epileptic) seizures. J Neurol Neurosurg Psychiatry 2013;84(7):822–4. doi: 10.1136/jnnp-2012-304842. Epub 2013 Mar 28. PMID: 23538071.