Abnormal brain oscillations persist after recovery from bipolar depression

Abnormal brain oscillations persist after recovery from bipolar depression

Author Canali, P. Google Scholar
Casarotto, S. Google Scholar
Rosanova, M. Google Scholar
Sferrazza-Papa, G. Google Scholar
Casali, A. G. Autor UNIFESP Google Scholar
Gosseries, O. Google Scholar
Massimini, M. Google Scholar
Smeraldi, E. Google Scholar
Colombo, C. Google Scholar
Benedetti, F. Google Scholar
Abstract When directly perturbed in healthy subjects, premotor cortical areas generate electrical oscillations in the beta range (20-40 Hz). In schizophrenia, major depressive disorder and bipolar disorder (BD), these oscillations are markedly reduced, in terms of amplitude and frequency. However, it still remains unclear whether these abnormalities can be modulated over time, or if they can be still observed after treatment. Here, we employed transcranial magnetic stimulation (TMS) combined with EEG to assess the frontal oscillatory activity in eighteen BD patients before/after antidepressant treatments (sleep deprivation and light therapy), relative to nine healthy controls. In order to detect dominant frequencies, event related spectral perturbations (ERSP) were computed for each TMS/EEG session in all participants, using wavelet decomposition. The natural frequency at which the cortical circuit oscillates was calculated as the frequency value with the largest power across 300 ms post-stimulus time interval. Severity of depression markedly decreased after treatment with 12 patients achieving response and nine patients achieving remission. TMS/EEG resulted in a significant activation of the beta/gamma band response (2150 Hz) in healthy controls. In patients, the main frequencies of premotor EEG responses to TMS did not significantly change before/after treatment and were always significantly lower than those of controls (11-27 Hz) and comparable in patients achieving remission and in those not responding to treatment. These results suggest that the reduction of natural frequencies is a trait marker of BD, independent from the clinical status of the patients. The present findings shed light on the neurobiological underpinning of severe psychiatric disorders and demonstrate that TMS/EEG represents a unique tool to develop biomarkers in psychiatry. (C) 2016 Elsevier Masson SAS. All rights reserved.
Keywords TMS/EEG
Gamma oscillations
Biomarkers
Bipolar disorder
GABAergic circuits
xmlui.dri2xhtml.METS-1.0.item-coverage Paris
Language English
Date 2017
Published in European Psychiatry. Paris, v. 41, p. 10-15, 2017.
ISSN 0924-9338 (Sherpa/Romeo, impact factor)
Publisher Elsevier France-Editions Scientifiques Medicales Elsevier
Extent 10-15
Origin http://dx.doi.org/10.1016/j.eurpsy.2016.10.005
Access rights Closed access
Type Article
Web of Science ID WOS:000397668400003
URI https://repositorio.unifesp.br/handle/11600/55065

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