<p>Improvement Of Frontal Lobe Dysfunction And White Matter Integrity By rTMS In Treatment-Resistant Depression</p>

Abstract

AimThe impairment experienced by many individuals with depression is closely related to the cognitive symptoms of the disorder. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation method providing a promising technique for improving cognitive symptoms in treatment-resistant depression (TRD). In the present study, we investigated whether a relationship exists between improvements in frontal lobe dysfunction induced by rTMS and improvement of white matter integrity revealed by diffusion tensor imaging (DTI) in TRD patients receiving rTMS treatment.MethodsA total of 12 patients with TRD were enrolled in a high-frequency (10 Hz) rTMS study (August 2013–January 2019). Frontal lobe function and depressive symptoms were assessed at baseline and at the endpoint of rTMS treatment. Fractional anisotropy (FA), as a measure of white matter integrity obtained from DTI, was investigated using a region-of-interest (ROI) approach.ResultsrTMS treatment significantly improved depressive symptom scores and some subscales of frontal lobe dysfunction. Category scores in the Word Fluency Test and scores on part 3 of the Color Stroop Test were improved independently of the improvement of depressive symptoms. In the ROI analysis, none of the FA increases in any region were correlated with improvement of any frontal lobe function (n = 12).ConclusionAlthough rTMS resulted in partial improvement of frontal lobe dysfunction as well as white matter integrity, we found no correlation between improved frontal lobe dysfunction and improved white matter integrity in TRD patients.

Connectivity changes in major depressive disorder after rTMS: a review of functional and structural connectivity data

“…After real rTMS, the authors also found increased FA in the left middle frontal gyrus whereas Tateishi et al . (2019) found higher FA values in the right superior frontal gyrus. Interestingly, Tateishi et al .…”

“…Interestingly, Tateishi et al . (2019) observed increased FA only in rTMS non-responders. In contrast, Peng et al .…”

“…Three studies examined the effect of rTMS on fractional anisotropy (FA), a marker of white matter microstructure, measured through DTI (Kozel et al ., 2011; Peng et al ., 2012; Tateishi et al ., 2019). All these studies included unipolar depressed patients.…”

“…While Tateishi et al . (2019) did not use a control group, the other two studies employed a sham stimulation group (Kozel et al ., 2011; Peng et al ., 2012) and a group of HC (Peng et al ., 2012). Specifically, Peng et al .…”

“…The three DTI studies here reviewed (Kozel et al ., 2011; Peng et al ., 2012; Tateishi et al ., 2019) reported increased FA, which suggests an improvement of white matter tracts integrity, in regions within the prefrontal lobe after rTMS treatment. These findings suggest the presence of a normalizing effect of rTMS treatment on prefrontal tracts, which have been often found to be characterised by reduced FA in MDD (Korgaonkar et al ., 2011; Chen et al ., 2016), similarly to what has been found for antidepressant treatments (Zeng et al ., 2012; Gryglewski et al ., 2020).…”