Cognitive behavioural therapy for adults with dissociative seizures (CODES): a pragmatic, multicentre, randomised controlled trial

Abstract

Background Dissociative seizures are paroxysmal events resembling epilepsy or syncope with characteristic features that allow them to be distinguished from other medical conditions. We aimed to compare the effectiveness of cognitive behavioural therapy (CBT) plus standardised medical care with standardised medical care alone for the reduction of dissociative seizure frequency. MethodsIn this pragmatic, parallel-arm, multicentre randomised controlled trial, we initially recruited participants at 27 neurology or epilepsy services in England, Scotland, and Wales. Adults (≥18 years) who had dissociative seizures in the previous 8 weeks and no epileptic seizures in the previous 12 months were subsequently randomly assigned (1:1) from 17 liaison or neuropsychiatry services following psychiatric assessment, to receive standardised medical care or CBT plus standardised medical care, using a web-based system. Randomisation was stratified by neuropsychiatry or liaison psychiatry recruitment site. The trial manager, chief investigator, all treating clinicians, and patients were aware of treatment allocation, but outcome data collectors and trial statisticians were unaware of treatment allocation. Patients were followed up 6 months and 12 months after randomisation. The primary outcome was monthly dissociative seizure frequency (ie, frequency in the previous 4 weeks) assessed at 12 months. Secondary outcomes assessed at 12 months were: seizure severity (intensity) and bothersomeness; longest period of seizure freedom in the previous 6 months; complete seizure freedom in the previous 3 months; a greater than 50% reduction in seizure frequency relative to baseline; changes in dissociative seizures (rated by others); health-related quality of life; psychosocial functioning; psychiatric symptoms, psychological distress, and somatic symptom burden; and clinical impression of improvement and satisfaction. p values and statistical significance for outcomes were reported without correction for multiple comparisons as per our protocol. Primary and secondary outcomes were assessed in the intention-to-treat population with multiple imputation for missing observations. This trial is registered with the International Standard Randomised Controlled Trial registry, ISRCTN05681227, and ClinicalTrials.gov, NCT02325544.

Psychological and demographic characteristics of 368 patients with dissociative seizures: data from the CODES cohort

“…We collected a wide range of clinical and demographic variables. Some of these measures were collected at consent to the screening phase of the overall study (Goldstein et al, 2019) and some were collected immediately pre-randomisation. We also recorded the Index of Multiple Deprivation (IMD) which gives a postcode-based measure of deprivation by locality, using the databases that were applicable when data collection commenced (Ministeries of Housing Communities and Local Government, 2010;Scottish Government, 2012;Welsh Government, 2011).…”

“…Patients developing DS over the age of 55 were more likely to be male, less likely to report previous sexual abuse, but more likely to report health-related traumatic experiences in one particular study (Duncan et al, 2006); in additon, there was a trend towards better mental health in the later onset subgroup. We have recently demonstrated that earlier age at DS onset is largely seen in women while men appear likely to develop DS at any age (Goldstein et al, 2019).…”

“…The large number of clinical centres involved in this prospective study avoids biases from smaller, single-centre studies. Some earlier measures on these patients have been reported elsewhere, along with all other patients who were initially consented to the screening phase of the RCT (Goldstein et al, 2019). We employed a wide range of measures in our RCT population, some of which had not previously been used in people with DS.…”

Retraining and control therapy for pediatric psychogenic non‐epileptic seizures

“…The success rate of ReACT is higher than studies using CBT for PNES in adults. 20,21,23,24 However, it is unclear if this is due to a difference in PNES between pediatric and adult populations or due to the treatment targets of the CBT treatments whereas adult PNES CBT treatments target fear avoidance 21,22 and work to reattribute patients' symptoms to psychosocial issues, 20,23,34 while ReACT aims to decrease catastrophic symptom expectations and directly retrain physical PNES symptoms in order to increase patients' control over their symptoms. 35 Second, it is noteworthy that significant reductions in PNES were demonstrated after ReACT, while anxiety and depression were not significantly changed.…”

“…22,23 In the largest RCT assessing CBT for PNES in adults by targeting fear avoidance, there was no difference in PNES between CBT with standard medical care and standard medical care alone at 12 months after treatment. 24 These negative results suggest mood is not the most effective PNES treatment target and support the investigation of novel treatment targets.…”