rTMS Affects Working Memory Performance, Brain Activation and Functional Connectivity in Patients with Multiple Sclerosis




Curated By TMS Solutions on Jul 4, 2017 12:00:00 AM
Curated By TMS Solutions

TITLE
rTMS Affects Working Memory Performance, Brain Activation and Functional Connectivity in Patients with Multiple Sclerosis 

AUTHORS
Hulst HE; Goldschmidt T; Nitsche MA; de Wit SJ; van den Heuvel OA; Barkhof F; Paulus W; van der Werf YD; Geurts JJG. Institution Hulst, H E. Department of Anatomy and Neurosciences, Section of Clinical Neuroscience, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. Goldschmidt, T. Department of Anatomy and Neurosciences, Section of Clinical Neuroscience, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. Nitsche, M A. Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany. Nitsche, M A. Department Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany. de Wit, S J. Department of Psychiatry, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. van den Heuvel, O A. Department of Anatomy and Neurosciences, Section of Clinical Neuroscience, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. van den Heuvel, O A. Department of Psychiatry, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. Barkhof, F. Department of Radiology and Nuclear Medicine, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. Paulus, W. Department of Clinical Neurophysiology, University of Gottingen, Gottingen, Germany. Paulus, W. Institutes of Neurology and Healthcare Engineering, UCL, London, United Kingdom. van der Werf, Y D. Department of Anatomy and Neurosciences, Section of Clinical Neuroscience, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. Geurts, J J G. Department of Anatomy and Neurosciences, Section of Clinical Neuroscience, VUmc MS Center Amsterdam, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.

SOURCE
Journal of Neurology, Neurosurgery & Psychiatry. 88(5):386-394, 2017 May.

OBECTIVE
To investigate the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) of the right dorsolateral prefrontal cortex (DLPFC) on working memory performance, while measuring task-related brain activation and task-related brain connectivity in patients with multiple sclerosis (MS).

METHODS
17 patients with MS and 11 healthy controls (HCs) underwent 3 experimental sessions (baseline, real-rTMS, sham-rTMS), all including an N-back task (3 task loads: N1, N2, N3; control condition: N0) inside the MR scanner. Prior to imaging, real-rTMS (10 Hz) was applied to the right DLPFC. The stimulation site was defined based on individually assessed N-back task activation at baseline and located using neuronavigation. Changes in whole brain functional activation and functional connectivity with the right DLPFC were calculated.

RESULTS
N-back task accuracy (N2 and N3) improved after real-rTMS (and not after sham-rTMS) compared with baseline (p=0.029 and p=0.015, respectively), only in patients. At baseline, patients with MS, compared with HCs, showed higher task-related frontal activation (left DLPFC, N2>N0), which disappeared after real-rTMS. Task-related (N1>N0) functional connectivity between the right DLPFC and the right caudate nucleus and bilateral (para)cingulate gyrus increased in patients after real-rTMS when compared with sham stimulation.

CONCLUSIONS
In patients with MS, N-back accuracy improved while frontal hyperactivation (seen at baseline relative to HCs) disappeared after real-rTMS. Together with the changes in functional connectivity after real-rTMS in patients, these findings may represent an rTMS-induced change in network efficiency in patients with MS, shifting patients' brain function towards the healthy situation. This implicates a potentially relevant role for rTMS in cognitive rehabilitation in MS.

Copyright Published by the BMJ Publishing Group Limited

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Topics: Memory, multiple-sclerosis, Medical Aspects


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