Cathodal HD-tDCS and attention: A study on patients with intractable left lateral frontal lobe epilepsy.

OBJECTIVE: Defects in the attentional network in patients with epilepsy are influenced by factors such as the location of epileptic foci. Examining the impact of cathodal high-definition transcranial direct current stimulation (HD-tDCS) on attention components could provide insights into potential attention-related side effects of tDCS. This study aimed to investigate the effect of cathodal HD-tDCS on interictal epileptiform discharges (IEDs), auditory/visual (A/V) attention components, and reaction time (RT) in patients with intractable focal left lateral frontal lobe epilepsy (LFLE). METHODS: To control for variations in individual epilepsy syndrome, 12 adult participants diagnosed with drug-resistant left LFLE with focal cortical IEDs on C3 underwent repeated measurements at pretest, posttest, and follow-up steps. 4 × 1 ring electrodes (cathode on C3 and four anodes on F3, P3, T3, and Cz) delivered 2 mA DC for 20 min per session for 10 consecutive days. The integrated visual and auditory continuous performance test (IVA+) assessed the A/V attention components and RT. One-way repeated-measure ANOVA was used. RESULTS: The findings suggest a significant effect in reducing IEDs. The IVA+ results showed a significant improvement in auditory divided attention and visual selective and focused attention (p < 0.05). In the follow-up, these changes demonstrated lasting efficacy. A/V speed scales increased (p < 0.05), showing a significant decrease in reaction time. CONCLUSIONS: Cathodal HD-tDCS significantly reduced IEDs and improved the components of auditory divided attention, visual focused attention, and visual selective attention, with a reduction in patient reaction time. A significant lasting, side-effect-free positive effect was observed for up to one month after the intervention.

Augmenting the unified protocol for transdiagnostic treatment of emotional disorders with transcranial direct current stimulation in individuals with generalized anxiety disorder and comorbid depression: A randomized controlled trial.

BACKGROUND: The aim of the current study was to compare the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP) with and without transcranial direct current stimulation (tDCS) in individuals suffering from generalized anxiety disorder (GAD) and comorbid depression. METHODS: A total of 43 individuals diagnosed with GAD and comorbid depression enrolled in a randomized controlled trial (IRCT20140929019334N1). Participants were randomly assigned to three groups including UP with tDCS (UP+tDCS; n = 15), UP alone (UP; n = 13) or wait-list control (n = 15). GAD and depression symptoms, worry severity, anxiety sensitivity, and intolerance of uncertainty were assessed at baseline, post-treatment and 3-month follow-up. RESULTS: Treatment with both UP+tDCS and UP alone resulted in significant lower ratings across all measures relative to wait-list controls at post-treatment and 3-month follow-up (all p-values <0.001). UP+tDCS showed significantly greater reductions in anxiety (p = 0.001 post-treatment; p = 0.003 follow-up), worry (p = 0.001 post-treatment; p = 0.002 follow-up), and anxiety sensitivity (p = 0.003 post-treatment; p = 0.002 follow-up) relative to UP alone. LIMITATIONS: The present study had some limitations. First, the sample size was low. Another limitation was the use of a short-term follow-up. CONCLUSIONS: These results suggest augmenting UP treatment with tDCS may be an efficacious strategy to improve treatment outcomes in GAD with comorbid depression. Trial registration reference is IRCT20140929019334N1 (see https://irct.ir/trial/27988).