scholarly journals Repetitive Transcranial Magnetic Stimulation of the Dorsolateral Prefrontal Cortex Modulates Electroencephalographic Functional Connectivity in Alzheimer’s Disease

2021 ◽  
Vol 13 ◽  
Author(s):  
Yi Guo ◽  
Ge Dang ◽  
Brenton Hordacre ◽  
Xiaolin Su ◽  
Nan Yan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Prefrontal Cortex ◽  
Functional Connectivity ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Beta Band ◽  
Cognitively Normal ◽  
Moderate Cognitive Impairment ◽  
Dorsolateral Prefrontal

Background: Increasing evidence demonstrates that repetitive transcranial magnetic stimulation (rTMS) treatment of the dorsolateral prefrontal cortex is beneficial for improving cognitive function in patients with Alzheimer’s disease (AD); however, the underlying mechanism of its therapeutic effect remains unclear.Objectives/Hypothesis: The aim of this study was to investigate the impact of rTMS to the dorsolateral prefrontal cortex on functional connectivity along with treatment response in AD patients with different severity of cognitive impairment.Methods: We conducted a 2-week treatment course of 10-Hz rTMS over the left dorsolateral prefrontal cortex in 23 patients with AD who were split into the mild or moderate cognitive impairment subgroup. Resting state electroencephalography and general cognition was assessed before and after rTMS. Power envelope connectivity was used to calculate functional connectivity at the source level. The functional connectivity of AD patients and 11 cognitively normal individuals was compared.Results: Power envelope connectivity was higher in the delta and theta bands but lower in the beta band in the moderate cognitive impairment group, compared to the cognitively normal controls, at baseline (p < 0.05). The mild cognitive impairment group had no significant abnormities. Montreal Cognitive Assessment scores improved after rTMS in the moderate and mild cognitive impairment groups. Power envelope connectivity in the beta band post-rTMS was increased in the moderate group (p < 0.05) but not in the mild group. No significant changes in the delta and theta band were found after rTMS in both the moderate and mild group.Conclusion: High-frequency rTMS to the dorsolateral prefrontal cortex modulates electroencephalographic functional connectivity while improving cognitive function in patients with AD. Increased beta connectivity may have an important mechanistic role in rTMS therapeutic effects.

Repetitive Transcranial Magnetic Stimulation Improves Depersonalization: A Case Report

CNS Spectrums ◽  
2004 ◽  
Vol 9 (5) ◽  
pp. 375-376 ◽  
Author(s):  
Alejandro M. Jiménez-Genchi
Keyword(s):  
Prefrontal Cortex ◽  
Case Report ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Treatment Resistant ◽  
Depersonalization Disorder ◽  
Dorsolateral Prefrontal

AbstractDepersonalization disorder is a poorly understood and treatment-resistant condition. This report describes a patient with depersonalization disorder who underwent six sessions of repetitive transcranial magnetic stimulation on the left dorsolateral prefrontal cortex. Repetitive transcranial magnetic stimulation produced a 28% reduction on depersonalization scores.

scholarly journals Mechanisms of transcranial magnetic stimulation in the treatment of anorexia nervosa

BJPsych Open ◽  
2021 ◽  
Vol 7 (S1) ◽  
pp. S49-S50
Author(s):  
Lydia Shackshaft
Keyword(s):  
Anorexia Nervosa ◽  
Prefrontal Cortex ◽  
Functional Connectivity ◽  
Resting State ◽  
High Frequency ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Resting State Functional Connectivity ◽  
Dorsolateral Prefrontal ◽  
Neurophysiological Mechanisms

AimsSevere and Enduring Anorexia Nervosa (SE-AN) is a challenging condition to treat, with limited therapeutic options, high morbidity, and the highest mortality rates of any psychiatric illness. Repetitive Transcranial Magnetic Stimulation (rTMS) is an emerging treatment option, as evidence demonstrates promising efficacy in improving mood and reducing core Anorexia Nervosa symptoms, as well as safety and tolerability to patients. We aimed to investigate the neurophysiological mechanisms of rTMS use in SE-AN patients by assessing changes in resting state functional connectivity, in the first functional neuroimaging analysis investigating rTMS effects in Anorexia Nervosa patients.Method26 females with a current diagnosis of SE-AN received 20 sessions of sham or real high frequency rTMS (10 hertz) to the left dorsolateral prefrontal cortex in a randomised double-blind trial. Resting-state functional magnetic resonance imaging was performed before and after rTMS. Neural correlates of rTMS treatment were identified using a seed-based functional connectivity analysis with the left dorsolateral prefrontal cortex and bilateral amygdalae as regions of interest. Functional connectivity differences were analysed using t-contrasts in a mixed ANOVA (flexible factorial analysis) to assess interactions between treatment group (real rTMS vs sham) and time-point (pre or post TMS).ResultNo statistically significant changes in resting-state functional connectivity were observed post-rTMS compared to baseline in participants receiving active rTMS compared to sham. Increased functional connectivity between the left amygdala and left pre-supplementary motor area was observed to reach cluster-wise significance (PFWE < 0.05). However, after Bonferroni correction for multiple comparisons (3 seed regions), this did not reach the significance threshold PFWE <0.017.ConclusionThis study highlights the need for further investigation of neurophysiological mechanisms, including resting-state functional connectivity modulation, resulting from rTMS to the dorsolateral prefrontal cortex in SE-AN patients. This requires higher powered studies to account for heterogeneity in treatment response. We have provided some indication that high frequency rTMS may have therapeutic benefit in SE-AN by modification of functional connectivity between prefrontal and limbic brain regions, resulting in improved top-down cognitive control over emotional processing and ability to enact goal-directed behaviours, enabling secondary reductions in eating disorder behaviours.

Clinical effectiveness of repetitive transcranial magnetic stimulation treatment in children and adolescents with neurodevelopmental disorders: A systematic review

Autism ◽  
2019 ◽  
Vol 23 (7) ◽  
pp. 1614-1629 ◽  
Author(s):  
Fumi Masuda ◽  
Shinichiro Nakajima ◽  
Takahiro Miyazaki ◽  
Ryosuke Tarumi ◽  
Kamiyu Ogyu ◽  
...  
Keyword(s):  
Systematic Review ◽  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Children And Adolescents ◽  
Neurodevelopmental Disorders ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Dorsolateral Prefrontal

Neurodevelopmental disorders, including autism spectrum disorder, are common in children and adolescents, but treatment strategies remain limited. Although repetitive transcranial magnetic stimulation has been studied for neurodevelopmental disorders, there is no clear consensus on its therapeutic effects. This systematic review examined literature on repetitive transcranial magnetic stimulation for children and adolescents with neurodevelopmental disorders published up to 2018 using the PubMed database. The search identified 264 articles and 14 articles met eligibility criteria. Twelve of these studies used conventional repetitive transcranial magnetic stimulation and two studies used theta burst stimulation. No severe adverse effects were reported in these studies. In patients with autism spectrum disorder, low-frequency repetitive transcranial magnetic stimulation and intermittent theta burst stimulation applied to the dorsolateral prefrontal cortex may have therapeutic effects on social functioning and repetitive behaviors. In patients with attention deficit/hyperactivity disorder, low-frequency repetitive transcranial magnetic stimulation applied to the left dorsolateral prefrontal cortex and high-frequency repetitive transcranial magnetic stimulation applied to the right dorsolateral prefrontal cortex may target inattention, hyperactivity, and impulsivity. In patients with tic disorders, low-frequency repetitive transcranial magnetic stimulation applied to the bilateral supplementary motor area improved tic symptom severity. This systematic review suggests that repetitive transcranial magnetic stimulation may be a promising intervention for children and adolescents with neurodevelopmental disorders. The results warrant further large randomized controlled trials of repetitive transcranial magnetic stimulation in children with neurodevelopmental disorders.

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