Clinical predictors of seizure threshold in electroconvulsive therapy: a prospective study

At the start and during the course of electroconvulsive therapy (ECT), estimation of the seizure threshold (ST) is useful in weighing the expected effectiveness against the risks of side effects. Therefore, this study explores clinical factors predicting initial ST (IST) and levels of ST during the ECT course. This prospective observational study included patients aged ≥18 years receiving ECT without contraindications for dose titration. At the first and every sixth consecutive ECT session, ST level was measured. Using multivariate linear regression and multilevel models, predictors for IST and change in ST levels were examined. A total of 91 patients (mean age, 59.1 ± 15.0 years; 37 % male; 97 % diagnosis of depression) were included. In multivariable analysis, higher age (β = 0.24; P = 0.03) and bifrontotemporal (BL) electrode placement (β = 0.42; P < 0.001) were independent predictors for higher IST, explaining 49 % of its variation. Also, these two variables independently predicted higher ST levels at different time points during the course. Using multilevel models, absence of a previous ECT course(s) predicted a steeper rise in ST during the course (P = 0.03 for the interaction term time*previous ECT). The age-adjusted dose-titration method is somewhat crude, resulting in some measurement error. Concomitant medication use could have influenced ST levels. Increasing age and BL electrode placement predicted higher (I)ST, which should be taken into account when selecting ECT dosage. Previous ECT course(s) may avoid an increase in ST during the course of ECT

Perceptions of free will in obsessive-compulsive disorder: a quantitative analysis

Abstract Background The aim of this study was to explore perceptions of free will in the repetitive behaviors of patients with obsessive-compulsive disorder (OCD) and to explore their relation with core clinical characteristics. Methods Experiences of free will were assessed with the Symptomatology And Perceived Free will rating scale (SAPF) in 295 subjects with a lifetime diagnosis of OCD. Patients’ scores on the SAPF were subjected to an explorative principal axis factor analysis (PAF). Factor scores were regressed on five OCD symptom dimensions and on seven clinical variables: illness duration, severity of OCD, insight, anxiety and depression, suicidal ideation and quality of life. Results The PAF revealed three factors: the perceived ability to control and change one’s course of action when faced with an obsession or compulsion (the “alternative possibilities” factor); the experience of obsessions or compulsions as intentional (the “intentionality” factor); and the experience of being the source or owner of the obsessions or compulsions (the “ownership” factor). Lower scores on the “alternative possibilities” factor were associated with lower scores on the washing dimension (β = 0.237, p = 0.004) and higher scores on the precision dimension (β = − 0.190, p = 0.025) and independently associated with longer illness duration (β = − 0.134, p = 0.039), higher illness severity (β = − 0.298, p < 0.001) and lower quality of life (β = 0.172, p = 0.046). Lower scores on the “intentionality” factor were independently associated with lower quality of life (β = 0.233, p = 0.027). Higher scores on the “ownership” factor were associated with higher scores on the precision dimension (β = 0.207, p = 0.023) and independently associated with poorer insight (β = 0.170, p = 0.045). Conclusions The most notable finding of this study is that a diminished experience of free will in OCD is associated with core clinical characteristics: illness duration and severity, insight and quality of life

MRI characteristics predicting seizure threshold in patients undergoing electroconvulsive therapy: a prospective study

BACKGROUND: In electroconvulsive therapy (ECT), the electrical current must pass the scalp, skull, cerebrospinal fluid (CSF) and brain tissues, to sufficiently exceed the seizure threshold (ST). OBJECTIVE: To investigate the relationship between these anatomical strata of the head and the level of the ST, in both right unilateral (RUL) and bifrontotemporal (BL) ECT. METHODS: Observational prospective study among 74 mainly depressed patients. STs were measured at the 1st (initial ST), 6th, 12th, 18th and 24th session. MRI scans were acquired before the 1st session. Scalp and skull thickness at electrode sites were measured on T2-weighted images. Volumes of intracranial space (ICV), CSF, gray and white matter, and white matter hyperintensities were estimated using whole brain isovoxel T1-weighted images. Separate multivariate regression analyses for RUL (n = 55) and BL (n = 19) treated groups were used to estimate the predictive values of the MRI variables. RESULTS: The patients had a mean age of 57.7 ± 14.8 years, and 39% were men. After adjustment for age, gender and ICV, CSF volume strongly and independently predicted initial ST in both RUL (β = 0.31; P = 0.049) and BL ECT (β = 0.64; P = 0.007). Using multilevel regression analysis, CSF volume was associated with ST during the remaining RUL ECT course (β = 0.20; P = 0.02). CONCLUSIONS: Taking into account the limitations in the titration method and MRI analysis, volume of CSF strongly and independently predicted initial ST. Therefore, the exclusive use of age-based ECT dosing methods may result in suboptimal electrical stimulus dosage in patients with CSF volumes that are not within the average range