Bilateral subthalamic nucleus stimulation improves balance control in Parkinson's disease.
BACKGROUND
Parkinson's disease (PD), the most common basal ganglia degenerative disease, affects balance control, especially when patients change balance strategy during postural tasks. Bilateral chronic stimulation of the subthalamic nucleus (STN) is therapeutically useful in advanced PD, and reduces the motor signs of patients. Nevertheless, the effects of STN stimulation on postural control are still debatable.


OBJECTIVE
To assess the impact of bilateral STN stimulation on balance control in PD and to determine how basal ganglia related sensorimotor modifications act on neurosensorial organisation of balance and motor postural programming.


METHODS
Twelve subjects aged 45-70 years underwent unified Parkinson's disease rating scale motor (part III) clinical tests, static and dynamic posturography, including sensory organisation and adaptation tests, shortly before and six months after bilateral implantation of electrodes into the STN.


RESULTS
The postoperative static test showed an improvement in postural control precision both in eyes open and eyes closed conditions. The dynamic test highlighted the decreased number of falls and the ability of the patients to develop more appropriate sensorimotor strategies when stimulated. The sensory organisation test showed an improvement of equilibrium score and, thus, a better resolution of sensorial conflicts.


CONCLUSIONS
STN stimulation allowed a reduction in rigidity and therefore an improvement in the ability to use muscular proprioception as reliable information, resulting in vestibulo-proprioceptive conflict suppression. STN stimulation has a synergistic effect with levodopa for postural control. Accordingly, non-dopaminergic pathways could be involved in postural regulation and STN stimulation may influence the functioning of these pathways.
Colnat-Coulbois
S
S
Department of Neurosurgery, University Hospital of Nancy, France.
Gauchard
G C
GC
Maillard
L
L
Barroche
G
G
Vespignani
H
H
Auque
J
J
Perrin
Ph P
PP
D000368:Aged; D001479:Basal Ganglia / Q000473:pathology; D046690:Deep Brain Stimulation / Q000295:instrumentation; D004567:Electrodes, Implanted; D004576:Electromyography / Q000295:instrumentation; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009127:Muscle Rigidity / Q000209:etiology / Q000517:prevention & control; D018482:Muscle, Skeletal / Q000294:innervation; D009410:Nerve Degeneration / Q000473:pathology; D019635:Neurosurgical Procedures; D010300:Parkinson Disease / Q000150:complications / Q000473:pathology / Q000628:therapy*; D011182:Postoperative Care; D004856:Postural Balance / Q000502:physiology*; D011300:Preoperative Care; D011434:Proprioception / Q000502:physiology; D012720:Severity of Illness Index; D020886:Somatosensory Disorders / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000502:physiology* / Q000601:surgery