Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT01931995 |
Other study ID # |
2012p001784 |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
February 2013 |
Est. completion date |
July 2018 |
Study information
Verified date |
June 2021 |
Source |
Massachusetts General Hospital |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
This research study is being done to gain a better understanding about brain networks that
may be involved in depression. The investigators plan to examine how these networks change
after the brain is stimulated with "Transcranial Magnetic Stimulation" (TMS). TMS is a way of
stimulating the brain in order to mildly activate or mildly suppress different brain areas,
and is used to treat some forms of depression. It is hoped that this study will facilitate
learning more about the structure and function of different brain areas and the ways that
they are interconnected to form networks, both in depressed people and in people without
depression. In this research study, the effects of TMS will be measured by obtaining
"pictures" of the brain with "Magnetic Resonance Imaging" (MRI) and with "Positron Emission
Tomography" (PET). More specifically, this will be accomplished with a combined MRI and PET
scanner, which is capable of simultaneously obtaining both MRI and PET images of the brain.
This scanning paradigm will allow the assessment of local metabolic changes resulting from
TMS (with PET images) and brain network changes resulting from TMS (with fMRI). Changes
resulting from TMS between 20 subjects with depression and 20 healthy volunteers will be
calculated and will form the main outcome measure.
Description:
Repetitive transcranial magnetic stimulation (rTMS), when delivered to the dorsolateral
prefrontal cortex (DLPFC) is a clinically effective treatment for major depressive disorder
(MDD). Network models of MDD are increasingly gaining acceptance, and functional connectivity
MRI (fcMRI) has revealed topographically specific aberrations in functional network
architecture in MDD. And yet, despite hints that the therapeutic effects of rTMS are actuated
through distributed impacts upon cortical and subcortical limbic centers, the network effects
of rTMS remain mysterious. This study seeks to investigate the way rTMS to DLPFC modulates
network functional connectivity between the site of stimulation and a critical limbic region,
the subgenual cingulate (sgACC), and between the sgACC and other limbic regions. In this
study, high frequency rTMS will be used to stimulate the left DLPFC (recapitulating the
therapeutic methodology), specifically, regions of the DLPFC that are functionally correlated
and anti-correlated with the sgACC. This will be accomplished in a group of patients with
MDD, and in a group of carefully matched controls. These subjects will be scanned before and
after rTMS is delivered, as a way of gauging its effects. The feasibility of this design was
recently demonstrated by our group (Eldaief et al. PNAS 2011). Changes induced by the
stimulation will be charted with a novel combined MRI-PET (Positron Emission Tomography)
scanner at the MGH Martinos Center, which is capable of simultaneously recording fcMRI BOLD
(Blood oxygenation level-dependent) and 18Flurodeoxyglucose (FDG) PET data. This will permit
cortico-limbic networks to be characterized dynamically through (1) examination of the
differential effects of stimulating two networks in the DLPFC, and (2) by tracking the
dynamic interplay between rTMS induced changes in local glucose metabolism at DLPFC and sgACC
on the one hand, and changes in distributed connectivity between these regions on the other.
In an exploratory aim, MDD patients will return three months later (after they have undergone
a non-specific treatment intervention with their psychiatric provider) for the identical
rTMS/fcMRI/FDG-PET procedures. This aim will establish, as proof of principle, that treatment
of MDD is associated with changes in cortico-limbic functional network architecture, and in
cortico-limbic dynamics. Eventually, it is hoped that this work will lead to the emergence of
aberrant cortical dynamics as a biomarker for MDD. In addition, this work might pollinate
future studies which use aberrant cortical dynamics as a novel therapeutic target upon which
neuromodulatory interventions might intervene.