Temporal changes in movement time during the switch of the stimulators in Parkinson's disease patients treated by subthalamic nucleus stimulation.
OBJECTIVE
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a very effective therapy for the advanced phase of Parkinson's disease (PD). The functional inhibition of this nucleus is responsible for a significant improvement of cardinal motor symptoms of PD. The aim of the study was the assessment of the effectiveness of STN DBS on bradykinesia by the analysis of movement time (MT) in 2 conditions: with the stimulators turned on ('stim-on') or off ('stim-off').


METHODS
After pharmacological wash-out, 10 patients submitted to bilateral STN DBS were studied with an MT analyser in 3 phases: stim-on, stim-off and stim-on again, in order to establish the time course of MT lengthening, the posteffect duration and the latency of the effect of STN DBS. MT data were then compared with the UPDRS motor scores.


RESULTS
After turning off the stimulators, MT progressively increases, reaching a plateau after about 30 min, which then lasts for the subsequent observation time (2 h). A significant elongation is achieved after the first 5 min. Upon pulse generator activation, MT shows a dramatic shortening, already significant after 2 min. Moreover, we observed a significant correlation between MT and the severity of PD, higher with bradykinesia than with rigidity or tremor.


CONCLUSIONS
Our findings show a relevant effect of STN DBS on MT, a parameter strongly related to bradykinesia. This study confirms the effectiveness of STN inhibition on the whole parkinsonian triad, suggesting that this target can be considered a proper choice for the surgical treatment of advanced PD.
Lopiano
Leonardo
L
Department of Neuroscience, University of Turin, Italy. leonardo.lopiano@libero.it
Torre
Elena
E
Benedetti
Fabrizio
F
Bergamasco
Bruno
B
Perozzo
Paola
P
Pollo
Antonella
A
Rizzone
Mario
M
Tavella
Alessia
A
Lanotte
Michele
M
D000368:Aged; D004599:Electric Stimulation Therapy; D005260:Female; D006801:Humans; D018476:Hypokinesia / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy*; D020531:Subthalamic Nucleus; D016896:Treatment Outcome