Deep Transcranial Magnetic Stimulation Effects on the Electrophysiological Parameters in Obsessive-Compulsive Disorder.

Backgrounds. Deep Transcranial Magnetic Stimulation (dTMS) is a non-invasive treatment cleared by FDA as a safe and efficient intervention for the treatment of depression and obsessive-compulsive disorder (OCD). Objectives. In this retrospective single-center study, the effects of dTMS on the electrophysiological parameters and the clinical outcomes of patients with OCD were tested. Methods. Thirty sessions of dTMS were administered to 29 OCD patients (15 female and 14 male). Quantitative electroencephalography (QEEG) recordings and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) were measured at baseline and endpoint. Paired sample t-test was used to measure the change in Y-BOCS scores and QEEG activity after dTMS practice. Results. All 29 patients responded to the dTMS intervention by indicating at least 35% reduction in Y-BOCS scores. QEEG recordings revealed a significant decrease in theta, alpha and the beta rhythms. The decrease in the severity of OCD symptoms correlated with the decrease in beta activity at left central region. Conclusions. Historically, excess fast oscillations in OCD are correlated with the unresponsiveness to selective serotonin reuptake inhibitor (SSRI) treatment. We hypothesize that the decrease in the power of beta bands by deep TMS is related to the mechanism of the therapeutic response.

Quantitative EEG Findings in Patients With Psychogenic Nonepileptic Seizures.

Objective. Psychogenic nonepileptic seizures (PNES), is one of the clinical manifestations of conversion disorder that epileptiform discharges do not accompany. Factors capable of increasing susceptibility to these seizures have not been adequately investigated yet. This study aims to investigate the quantitative electroencephalography (QEEG) findings for PNES by evaluating the resting EEG spectral power changes during the periods between seizures. Methods. Thirty-nine patients (29 females, 10 males) diagnosed with PNES (group 1) and 47 patients (23 females, 24 males) without any psychiatric diagnosis (group 2) were included in the study. The patients underwent a psychiatric examination at their first visit, were diagnosed and their EEGs were recorded. Using fast Fourier transformation (FFT), spectral power analysis was calculated for delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), beta (15-30 Hz), high-beta (25-30 Hz), gamma-1 (31-40 Hz), gamma-2 (41-50 Hz), and gamma (30-80 Hz) frequency bands. Results. Six separate EEG band power, namely (C3-high beta, C3-gamma, C3-gamma-1, C3-gamma-2, P3-gamma, P3 gamma-1), were found to be higher in the patients diagnosed with PNES than in the control group. Conclusion. Our findings show that PNES correlate with high-frequency oscillations on central motor and somatosensory cortices.