Effect of electroconvulsive therapy on cortical excitability in patients with major depression: a transcranial magnetic stimulation study.
OBJECTIVE
The antidepressant action of electro-convulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS) may be related to their ability to modulate cortical excitability. The aim of this study was to investigate changes in cortical excitability following ECT in patients with major depression (MD) and to compare therapeutic efficacy of ECT combined with rTMS to that of ECT alone.


METHODS
Twenty-two patients with MD were assigned to receive ECT and right prefrontal 1 Hz rTMS (n=12) or ECT with sham rTMS (n=10). ECT was given twice weekly and rTMS was applied on the remaining 4 days, throughout 3 weeks. The resting motor threshold (rMT) and motor evoked potential (MEP)/M-wave area ratio were evaluated before and 6 h after the first, third and sixth ECT session. The active motor threshold (aMT), intra-cortical inhibition (ICI) and intra-cortical facilitation (ICF) were measured at baseline and 24 h after the last ECT.


RESULTS
There were no significant differences in the degree of clinical improvement and measures of cortical excitability in the ECT+active rTMS group as compared to the ECT+sham rTMS group. Marked clinical improvement observed in 19 out of the 22 patients was associated with a significant increase of the MEP/M-wave area ratio, decrease of the aMT and reduction of the ICI in the left hemisphere.


CONCLUSIONS
The antidepressant effect of ECT was associated with an enhancement of left hemispheric excitability. rTMS did not add to the beneficial effect of ECT. However, the small sample size and the robust effect of ECT might have obscured a potential therapeutic effect of rTMS.


CONCLUSIONS
Measures of cortical excitability may provide insight to our understanding of the mechanism of action of ECT and might be useful for the assessment of treatment response.
Chistyakov
Andrei V
AV
Laboratory of Clinical Neurosciences, Department of Neurosurgery, Rambam (Maimonides) Medical Center, B. Rappaport Faculty of Medicine, The Technion, Israel Institute of Technology, Haifa, Israel. a_chistyakov@rambam.health.gov.il
Kaplan
Boris
B
Rubichek
Odil
O
Kreinin
Isabella
I
Koren
Dani
D
Hafner
Hava
H
Feinsod
Moshe
M
Klein
Ehud
E
D000368:Aged; D002540:Cerebral Cortex / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000628:therapy*; D004565:Electroconvulsive Therapy; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009433:Neural Inhibition; D017397:Prefrontal Cortex / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation / Q000627:therapeutic use*; D016896:Treatment Outcome