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R epetitive transcranial magnetic stimulation induced modulations of resting state motor connectivity in writer's cramp
Author(s) -
Bharath R. D.,
Biswal B. B.,
Bhaskar M. V.,
Gohel S.,
Jhunjhunwala K.,
Panda R.,
George L.,
Gupta A. K.,
Pal P. K.
Publication year - 2015
Publication title -
european journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 124
eISSN - 1468-1331
pISSN - 1351-5101
DOI - 10.1111/ene.12653
Subject(s) - transcranial magnetic stimulation , functional magnetic resonance imaging , resting state fmri , putamen , supplementary motor area , thalamus , globus pallidus , medicine , neuroscience , motor cortex , cerebellum , magnetic resonance imaging , stimulation , psychology , basal ganglia , central nervous system , radiology
Background and purpose Writer's cramp ( WC ) is a focal task‐specific dystonia of the hand which is increasingly being accepted as a network disorder. Non‐invasive cortical stimulation using repetitive transcranial magnetic stimulation (r TMS ) has produced therapeutic benefits in some of these patients. This study aimed to visualize the motor network abnormalities in WC and also its rTMS induced modulations using resting state functional magnetic resonance imaging (rsf MRI ). Methods Nineteen patients with right‐sided WC and 20 matched healthy controls ( HC s) were prospectively evaluated. All patients underwent a single session of r TMS and rsf MRI was acquired before ( R 1) and after ( R 2) r TMS . Seed‐based functional connectivity analysis of several regions in the motor network was performed for HC s, R 1 and R 2 using SPM 8 software. Thresholded ( P < 0.05, false discovery rate corrected) group level mean correlation maps were used to derive significantly connected region of interest pairs. Results Writer's cramp showed a significant reduction in resting state functional connectivity in comparison with HCs involving the left cerebellum, thalamus, globus pallidus, putamen, bilateral supplementary motor area, right medial prefrontal lobe and right post central gyrus. After r TMS there was a significant increase in the contralateral resting state functional connectivity through the left thalamus−right globus pallidus−right thalamus−right prefrontal lobe network loop. Conclusions It is concluded that WC is a network disorder with widespread dysfunction much larger than clinically evident and changes induced by r TMS probably act through subcortical and trans‐hemispheric unaffected connections. Longitudinal studies with therapeutic r TMS will be required to ascertain whether such information could be used to select patients prior to r TMS therapy.