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Altered inhibitory interaction among inferior frontal and motor cortex in l ‐dopa‐induced dyskinesias
Author(s) -
Ponzo Viviana,
Picazio Silvia,
Benussi Alberto,
Di Lorenzo Francesco,
Brusa Livia,
Caltagirone Carlo,
Koch Giacomo
Publication year - 2016
Publication title -
movement disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.352
H-Index - 198
eISSN - 1531-8257
pISSN - 0885-3185
DOI - 10.1002/mds.26520
Subject(s) - transcranial magnetic stimulation , motor cortex , disinhibition , levodopa , neuroscience , stimulation , cortex (anatomy) , frontal lobe , psychology , inhibitory postsynaptic potential , medicine , parkinson's disease , disease
Background Levodopa‐induced dyskinesias are associated with thalamo‐cortical disinhibition and frontal area overactivation. Neuroimaging and transcranial magnetic stimulation studies have highlighted the involvement of the right inferior frontal cortex in levodopa‐induced dyskinesias. Methods Using transcranial magnetic stimulation, we tested connectivity between the inferior frontal and contralateral motor cortex in Parkinson's disease patients with and without levodopa‐induced dyskinesias compared with age‐matched controls. Furthermore, in dyskinetic patients, connectivity between the inferior frontal and contralateral motor cortex was assessed before and after a single session of continuous theta‐burst stimulation applied over the inferior frontal cortex. Results Dyskinetic patients showed abnormal facilitatory connectivity between the inferior frontal and motor cortex when compared with the nondyskinetic group. Continuous theta‐burst stimulation over the inferior frontal cortex eliminated such facilitatory connectivity and decreased the levodopa‐induced dyskinesias that was induced by a supramaximal dose of levodopa. Conclusion In dyskinetic patients, a weaker inhibitory cortico‐cortical interaction between the inferior frontal and contralateral motor cortex could be involved in levodopa‐induced dyskinesias and restored by continuous theta‐burst stimulation over the inferior frontal cortex. © 2016 Movement Disorder Society