title: Primary motor cortex LTP/LTD-like plasticity in probable corticobasal syndrome.
abstract: Whether the primary motor cortex (M1) contributes to the pathophysiology of corticobasal syndrome (CBS) remains unclear. In this study in patients with probable CBS, we tested whether M1 plasticity contributes to the pathophysiology of symptoms in the contralateral "less affected" limb, manifesting only parkinsonism, and in the contralateral "more affected" limb, manifesting parkinsonism plus other motor and nonmotor symptoms. In Experiment 1, we applied intermittent/continuous theta-burst stimulation (iTBS/cTBS) over the M1 contralateral to the less affected limb in 17 patients. In Experiment 2, we applied iTBS/cTBS over the M1 contralateral to the more affected limb in 14 of the 17 patients. We measured iTBS/cTBS-induced plasticity as reflected by motor-evoked potential (MEP) changes. Data were compared with those obtained in 17 healthy subjects (HS). In Experiment 1, TBS over the M1 contralateral to the less affected limb disclosed reduced plasticity in patients than in HS. In Experiment 2, in 5 of 14 patients we recorded abnormally low-amplitude MEPs, preventing the evaluation of plasticity in the M1 contralateral to the more affected limb. In the remaining nine patients, TBS disclosed abnormal plasticity characterized by high intersubject variability. In these nine patients, the response to TBS correlated with specific patients' clinical features. In the present study in patients with probable CBS, we have demonstrated heterogeneous abnormalities of M1 that contribute to the pathophysiology of this condition.
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy; and Neuromed Institute, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Suppa
authors.affiliation: Neuromed Institute, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: Di Stasio
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy; and.
authors.forename: Luca
authors.initials: L
authors.lastname: Marsili
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy; and.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Upadhyay
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy; and Neuromed Institute, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Belvisi
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy; and Neuromed Institute, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Conte
authors.affiliation: Neuromed Institute, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Modugno
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy; and.
authors.forename: Carlo
authors.initials: C
authors.lastname: Colosimo
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy; and Neuromed Institute, "Sapienza" University of Rome, Rome, Italy alfredo.berardelli@uniroma1.it.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001072:Apraxias / Q000503:physiopathology*; D001479:Basal Ganglia / Q000503:physiopathology; D016022:Case-Control Studies; D019054:Evoked Potentials, Motor; D005121:Extremities / Q000294:innervation; D005260:Female; D006801:Humans; D017774:Long-Term Potentiation; D036881:Long-Term Synaptic Depression; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D013577:Syndrome; D013826:Theta Rhythm
keywords: corticobasal syndrome; plasticity; primary motor cortex; theta-burst stimulation