title: Effects of subthalamic nucleus deep brain stimulation and L-DOPA on blinking in Parkinson's disease.
abstract: In this study we asked whether subthalamic nucleus deep brain stimulation (STN-DBS) alone, or in combination with l-dopa, modifies voluntary, spontaneous and reflex blinking in patients with Parkinson's disease (PD). Sixteen PD patients who underwent STN-DBS were studied in four experimental conditions: without STN-DBS and without l-dopa, STN-DBS alone, l-dopa alone and STN-DBS plus l-dopa. The results were compared with those obtained in 15 healthy controls. Voluntary blinking was assessed by asking participants to blink as fast as possible; spontaneous blinking was recorded during two 60s rest periods; reflex blinking was evoked by electrical stimulation of the supraorbital nerve. Blinking were recorded and analysed with the SMART motion system. STN-DBS increased the peak velocity and amplitude for both the closing and opening voluntary blink phases, but prolonged the inter-phase pause duration. l-dopa had no effects on voluntary blinking but reversed the increased inter-phase pause duration seen during STN-DBS. Spontaneous blink rate increased after either STN-DBS or l-dopa. Reflex blinking kinematics were not modified by STN-DBS or l-dopa. The STN-DBS effects on voluntary blinking kinematics and spontaneous blinking rate may occur as results of changes of cortico-basal ganglia activity. The prolonged pause duration of voluntary blinking indicates that STN-DBS has detrimental effects on the cranial region. These results also shed light on the pathophysiology of eyelids opening apraxia following STN-DBS.
authors.affiliation: Neuromed Institute (IRCSS), Pozzilli (IS), Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bologna
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fasano
authors.forename: Nicola
authors.initials: N
authors.lastname: Modugno
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fabbrini
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001767:Blinking / Q000187:drug effects* / Q000502:physiology; D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D007980:Levodopa / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000503:physiopathology*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa