The use of background EEG activity to determine stimulus timing as a means of improving rTMS efficacy in the treatment of depression: A controlled comparison with standard techniques
Received 3 March 2009; received in revised form 20 August 2009; accepted 21 August 2009. published online 22 September 2009.
Background
Repetitive transcranial magnetic stimulation (rTMS) treatment of depression utilizes numerous predetermined patterns of stimulation. As an alternative to using invariant stimulus timing parameters, the interactive technique delivers individual stimuli based on the background electroencephalogram (EEG) activity.
Objective
This study examines the use of an EEG-dependent technique as a means to enhance the efficacy of rTMS in the treatment of depression.
Methods
Forty-four patients with treatment-refractory major depression were treated, in a randomized, doubleblind, 4-week trial, with two different rTMS stimulus timing techniques (left dorsolateral prefrontal cortex). Standard rTMS utilized 10-Hz stimuli, whereas interactive rTMS applied individual stimuli in response to a selected pattern of background EEG activity analyzed in real time. Hamilton Depression Rating Scale (HDRS) and the Beck's Depression Inventory-II (BDI) scores were recorded at baseline, 2 weeks and after the final treatment.
Results
The interactive group showed a trend toward greater efficacy than the standard group in both absolute (t=−1.68; P=.100) and percentage (t=−1.74; P=.090) change in scores on HDRS (and similarly BDI). The response rate (>50% reduction) for the interactive technique of 43% (9/21) was also different to that of the standard technique (22%; 5/23; odds ratio: 2.70).
Conclusions
The use of EEG-based TMS stimuli has been shown to be feasible in an rTMS clinical trial in treatment-resistant depression. The EEG-based interactive technique was associated with an indication of a trend toward a greater clinical effect than the standard rTMS technique. The interactive technique thus has the potential to refine the rTMS methodology and to enhance efficacy in the treatment of depression.
aStatewide Department of Neurophysiology, North Metropolitan Area Health Service-Mental Health, Perth, Australia
bCentre for Clinical Research in Neuropsychiatry/School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Australia
cSchool of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Australia
dGraylands Hospital, North Metropolitan Area Health Service-Mental Health, Perth, Australia
Correspondence: Gregory W. Price, PhD, Centre for Clinical Research in Neuropsychiatry, Private Mail Bag 1, Brockway Road, Mount Claremont, Western Australia, 6010.
The research was supported by equipment and infrastructure funding from the Statewide Department of Neurophysiology, North Metropolitan Area Health Service–Mental Health (NMAHS-MH), Department of Health, Western Australia.
J.W.Y.L. has been a speaker for AstraZeneca, Eli Lilly, Janssen-Cilag, Sanofi Aventis, Organon, and Pfizer. He has also received research grant support from Eli Lilly and Janssen-Cilag.
G.W.P. has a patent granted (2002) relating to interactive ERP stimulation.
The other authors report no potential conflicts of interests or biomedical financial interests.
ABSTRACT