title: The effect of L-dopa in Parkinson's disease as revealed by neurophysiological studies of motor and sensory functions.
abstract: This review will first discuss evidence of motor and sensory abnormalities as yielded by neurophysiological techniques in patients with PD. It will then go on to describe the effects of L-dopa replacement on motor and sensory abnormalities in PD as assessed by neurophysiological studies. Areas covered: We analyzed papers in English using Pubmed with the following keywords: L-dopa, dopamine, bradykinesia, basal ganglia, kinematic analysis, TMS, motor cortex plasticity, motor cortex excitability, somatosensory discrimination threshold, pain Expert commentary: L-dopa improves the amplitude and speed of upper limb voluntary movements, but it does not restore abnormalities in the sequence effect or voluntary facial movements. L-dopa only partially normalizes changes in motor cortex excitability and plasticity and has also contrasting effects on the sensory system and on sensory-motor integration. The neurophysiological studies reviewed here show that PD is more than a hypo-dopaminergic disease, and non-dopaminergic mechanisms should also be considered.
authors.affiliation: a Department of Neurology and Psychiatry , Sapienza University of Rome and Neuromed Institute IRCCS , Pozzilli , Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Suppa
authors.affiliation: a Department of Neurology and Psychiatry , Sapienza University of Rome and Neuromed Institute IRCCS , Pozzilli , Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bologna
authors.affiliation: a Department of Neurology and Psychiatry , Sapienza University of Rome and Neuromed Institute IRCCS , Pozzilli , Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Conte
authors.affiliation: a Department of Neurology and Psychiatry , Sapienza University of Rome and Neuromed Institute IRCCS , Pozzilli , Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
authors.affiliation: a Department of Neurology and Psychiatry , Sapienza University of Rome and Neuromed Institute IRCCS , Pozzilli , Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fabbrini
mesh_terms: D000978:Antiparkinson Agents / Q000627:therapeutic use*; D004298:Dopamine / Q000378:metabolism; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D009044:Motor Cortex; D010146:Pain / Q000188:drug therapy; D010300:Parkinson Disease / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa; D004298:Dopamine
keywords: Levodopa; Parkinson disease; kinematic; motor cortex excitability; motor cortex plasticity; sequence effect; somatosensory temporal discrimination threshold