title: Altered inhibitory interaction among inferior frontal and motor cortex in l-dopa-induced dyskinesias.
abstract: 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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors: Non-invasive Brain Stimulation Unit, Santa Lucia Foundation, Rome, Italy.
authors: Viviana
authors: V
authors: Ponzo
authors: Non-invasive Brain Stimulation Unit, Santa Lucia Foundation, Rome, Italy.
authors: Silvia
authors: S
authors: Picazio
authors: Centre for Ageing Brain and Neurodegenerative Disorders, Department of Clinical and Experimental Sciences, Neurology Unit, University of Brescia, Brescia, Italy.
authors: Alberto
authors: A
authors: Benussi
authors: Non-invasive Brain Stimulation Unit, Santa Lucia Foundation, Rome, Italy.
authors: Francesco
authors: F
authors: Di Lorenzo
authors: Neurology Department, S. Eugenio Hospital, Rome, Italy.
authors: Livia
authors: L
authors: Brusa
authors: Non-invasive Brain Stimulation Unit, Santa Lucia Foundation, Rome, Italy.|System Medicine Department, Tor Vergata University, Rome, Italy.
authors: Carlo
authors: C
authors: Caltagirone
authors: Non-invasive Brain Stimulation Unit, Santa Lucia Foundation, Rome, Italy.|Stroke Unit, Department of Neuroscience, Policlinico Tor Vergata, Rome, Italy.
authors: Giacomo
authors: G
authors: Koch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000978:Antiparkinson Agents / Q000009:adverse effects*; D004409:Dyskinesia, Drug-Induced / Q000503:physiopathology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D007980:Levodopa / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa
keywords: Parkinson's disease; connectivity; inferior frontal cortex; levodopa-induced dyskinesia; transcranial magnetic stimulation