Exploring the efficacy of a 5-day course of transcranial direct current stimulation (TDCS) on depression and memory function in patients with well-controlled temporal lobe epilepsy

• Published in: Epilepsy & behavior Vol. 55; pp. 11 - 20
• Main Authors: Liu, Anli, Bryant, Andrew, Jefferson, Ashlie, Friedman, Daniel, Minhas, Preet, Barnard, Sarah, Barr, William, Thesen, Thomas, O'Connor, Margaret, Shafi, Mouhsin, Herman, Susan, Devinsky, Orrin, Pascual-Leone, Alvaro, Schachter, Steven
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2016
• Subjects: Adult; Depression; Depressive Disorder - etiology; Depressive Disorder - psychology; Depressive Disorder - therapy; Double-Blind Method; Electroencephalography; Epilepsy, Temporal Lobe - complications; Epilepsy, Temporal Lobe - psychology; Epilepsy, Temporal Lobe - therapy; Female; Follow-Up Studies; Humans; Male; Memory; Memory Disorders - etiology; Memory Disorders - psychology; Memory Disorders - therapy; Memory, Short-Term; Middle Aged; Neurology; Neuropsychological Tests; Neurostimulation; Prefrontal Cortex; Psychiatric Status Rating Scales; Psychomotor Performance; Quality of Life; Stimulation safety; Temporal lobe epilepsy; Transcranial direct current stimulation; Transcranial Direct Current Stimulation - adverse effects; Neurostimulation; Temporal lobe epilepsy; Depression; Stimulation safety; Transcranial direct current stimulation; Memory
• ISSN: 1525-5050; 1525-5069; 1525-5069
• DOI: 10.1016/j.yebeh.2015.10.032

Depression and memory dysfunction significantly impact the quality of life of patients with epilepsy. Current therapies for these cognitive and psychiatric comorbidities are limited. We explored the efficacy and safety of transcranial direct current stimulation (TDCS) for treating depression and memory dysfunction in patients with temporal lobe epilepsy (TLE). Thirty-seven (37) adults with well-controlled TLE were enrolled in a double-blinded, sham-controlled, randomized, parallel-group study of 5days of fixed-dose (2mA, 20min) TDCS. Subjects were randomized to receive either real or sham TDCS, both delivered over the left dorsolateral prefrontal cortex. Patients received neuropsychological testing and a 20-minute scalp EEG at baseline immediately after the TDCS course and at 2- and 4-week follow-up. There was improvement in depression scores immediately after real TDCS, but not sham TDCS, as measured by changes in the Beck Depression Inventory (BDI change: −1.68 vs. 1.27, p<0.05) and NDDI-E (−0.83 vs. 0.9091, p=0.05). There was no difference between the groups at the 2- or 4-week follow-up. There was no effect on delayed or working memory performance. Transcranial direct current stimulation was well-tolerated and did not increase seizure frequency or interictal discharge frequency. Transcranial direct current stimulation induced an increase in delta frequency band power over the frontal region and delta, alpha, and theta band power in the occipital region after real stimulation compared to sham stimulation, although the difference did not reach statistical significance. This study provides evidence for the use of TDCS as a safe and well-tolerated nonpharmacologic approach to improving depressive symptoms in patients with well-controlled TLE. However, there were no changes in memory function immediately following or persisting after a stimulation course. Further studies may determine optimal stimulation parameters for maximal mood benefit. •A five-day course of TDCS has a modest but significant benefit in improving depressive symptoms in adult patients with well controlled TLE, but the effects did not persist to the 2- and 4- week follow up.•There is no effect on delayed recall or working memory function after a 5-day course of TDCS.•TDCS does not increase seizure frequency or interictal discharge frequency, and is well tolerated among patients.•TDCS induced an increase in delta frequency power over the frontal region and delta, theta, and alpha power in the occipital region, immediately after stimulation, compared to sham stimulation, although this did not reach statistical significance.