Single pulse TMS to the DLPFC, compared to a matched sham control, induces a direct, causal increase in caudate, cingulate, and thalamic BOLD signal.
Brain Stimul
; 11(4): 789-796, 2018.
Article
em En
| MEDLINE
| ID: mdl-29530447
ABSTRACT
BACKGROUND:
In the 20 years since our group established the feasibility of performing interleaved TMS/fMRI, no studies have reported direct comparisons of active prefrontal stimulation with a matched sham. Thus, for all studies there is concern about what is truly the TMS effect on cortical neurons.OBJECTIVE:
After developing a sham control for use within the MRI scanner, we used fMRI to test the hypothesis of greater regional BOLD responses for active versus control stimulation.METHODS:
We delivered 4 runs of interleaved TMS/fMRI with a limited field of view (16 slices, centered at AC-PC) to the left DLPFC (2 active, 2 control; counterbalanced) of 20 healthy individuals (F3; 20 pulses/run, interpulse interval10-15sec, TR1sec). In the control condition, 3â¯cm of foam was placed between the TMS coil and the scalp. This ensured magnetic field decay, but preserved the sensory aspects of each pulse (empirically evaluated in a subset of 10 individuals).RESULTS:
BOLD increases in the cingulate, thalamus, insulae, and middle frontal gyri (pâ¯<â¯0.05, FWE corrected) were found during both active and control stimulation. However, relative to control, active stimulation caused elevated BOLD signal in the anterior cingulate, caudate and thalamus. No significant difference was found in auditory regions. CONCLUSION(S) This TMS/fMRI study evaluated a control condition that preserved many of the sensory features of TMS while reducing magnetic field entry. These findings support a relationship between single pulses of TMS and activity in anatomically connected regions, but also underscore the importance of using a sham condition in future TMS/fMRI studies.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tálamo
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Imageamento por Ressonância Magnética
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Núcleo Caudado
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Córtex Pré-Frontal
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Estimulação Magnética Transcraniana
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Giro do Cíngulo
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Brain Stimul
Ano de publicação:
2018
Tipo de documento:
Article