Effects of deep brain stimulation and levodopa on postural sway in Parkinson's disease

Department of Electronics, Computer Science and Systems, University of Bologna, Bologna, Italy.
Journal of Neurology Neurosurgery & Psychiatry (Impact Factor: 6.81). 10/2002; 73(3):267-74.
Source: PubMed


To quantify postural sway in subjects with Parkinson's disease and elderly controls, and determine the effects of Parkinson's disease, deep brain stimulation, levodopa, and their interactions on postural control during quiet stance.
Centre of foot pressure (CoP) displacement under each foot was measured during three 60 s trials of quiet stance with eyes open in 11 controls and six patients with Parkinson's disease. Subjects with Parkinson's disease were tested in four treatment conditions: off both deep brain stimulation and levodopa (off condition); on deep brain stimulation; on levodopa; and on both deep brain stimulation and levodopa. The variables extracted from CoP included: root mean square distance (rms), mean velocity, 95% power frequency (f(95%)), area of the 95% confidence ellipse (ellipse area), direction of its major axis (mdir), and postural asymmetry between the feet.
rms and area of postural sway were larger than normal in subjects with Parkinson's disease in the off condition, increased further with levodopa, and significantly decreased with deep brain stimulation. Mean velocity and f(95%) were also larger than normal but were restored to normal by all treatments, especially by deep brain stimulation. The combined effect of deep brain stimulation and levodopa resulted in a postural sway that was an average of the effect of each treatment individually. Levodopa increased sway more in the mediolateral than in the anterior-posterior direction. Subjects with Parkinson's disease had asymmetrical mean velocity and f(95%) between the feet, and this asymmetry increased with levodopa but decreased with deep brain stimulation. The f(95%) of the CoP correlated with tremor, posture, and gait subcomponents of the unified Parkinson's disease rating scale.
Subjects with Parkinson's disease have abnormal postural sway in stance. Treatment with levodopa increases postural sway abnormalities, whereas treatment with deep brain stimulation improves postural sway. Quantitative evaluation of static posturography may be a useful adjunct to clinical measures in patients with Parkinson's disease.

Download full-text


Available from: Lorenzo Chiari
  • Source
    • "The mean center of pressure ( CoP ) signal was also calculated for each analysis . For bipedal and tandem standing , the resultant CoP signal of the ground reaction forces was determined in a 2 - dimensional transverse plane by means of digital moment - of - force calculations for each force plate ( Rocchi et al . , 2002 ; Geurts et al . , 2011 ) . For unipedal adapted standing , the CoP was calculated in a similar manner as for the other conditions , but only for one force plate . In the tandem standing con - dition , the CoP of the limb positioned behind was used for the analysis . The first 10 s of each recording were ignored to avoid potential distu"
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to investigate the effects of disease severity and medication state on postural control asymmetry during challenging tasks in individuals with Parkinson's disease (PD). Nineteen people with PD and 11 neurologically healthy individuals performed three standing task conditions: bipedal standing, tandem and unipedal adapted standing; the individuals with PD performed the tasks in ON and OFF medication state. The participants with PD were distributed into 2 groups according to disease severity: unilateral group (n=8) and bilateral group (n=11). The two PD groups performed the evaluations both under and without the medication. Two force plates were used to analyze the posture. The symmetric index was calculated for various of center of pressure. ANOVA one-way (groups) and two-way (PD groups×medication), with repeated measures for medication, were calculated. For main effects of group, the bilateral group was more asymmetric than CG. For main effects of medication, only unipedal adapted standing presented effects of PD medication. There was PD groups×medication interaction. Under the effects of medication, the unilateral group presented lower asymmetry of RMS in anterior-posterior direction and area than the bilateral group in unipedal adapted standing. In addition, the unilateral group presented lower asymmetry of mean velocity, RMS in anterior-posterior direction and area in unipedal standing and area in tandem adapted standing after a medication dose. Postural control asymmetry during challenging postural tasks was dependent on disease severity and medication state in people with PD. The bilateral group presented higher postural control asymmetry than the control and unilateral groups in challenging postural tasks. Finally, the medication dose was able to reduce postural control asymmetry in the unilateral group during challenging postural tasks.
    Full-text · Article · Apr 2016 · Human movement science
  • Source
    • "However, there have been mixed results on whether quantitatively measured balance is also improved. Some aspects of balance control, such as postural sway when standing, show improvement when DBS is turned on (Rocchi et al. 2002). In-place postural responses also improve when DBS is turned on compared with off DBS; however, compared with presurgery function there is no overall improvement, with STN-DBS showing worsening compared with GPi-DBS (St George et al. 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The effects of Deep Brain Stimulation (DBS) on balance in people with Parkinson's Disease (PD) are not well established. This study examined whether DBS randomized to the subthalamic nucleus (STN, n=11) or globus pallidus interna (GPi, n=10) improved compensatory stepping to recover balance following a perturbation. The standing surface translated backwards, forcing subjects to take compensatory steps forward. Kinematic and kinetic responses were recorded. PD-DBS subjects were tested off and on their levodopa medication before bilateral DBS surgery, and retested six months later off and on DBS, combined with off and on levodopa medication. Responses were compared with PD-control subjects (n=8) tested over the same time scale and 17 healthy control subjects. Neither DBS nor levodopa improved the stepping response. Compensatory stepping in the best-treated state after surgery (DBS+DOPA) was similar to the best-treated state before surgery (DOPA) for the PD-GPi group and the PD control group. For the PD-STN group, there were more lateral weight shifts, a delayed foot-off and a greater number of steps required to recover balance in DBS+DOPA after surgery, compared to DOPA before surgery. Within the STN group, 5 subjects who did not fall during the experiment before surgery fell at least once after surgery, whereas the number of falls in the GPi and PD-control groups were unchanged. DBS did not improve the compensatory step response needed to recover from balance perturbations in the GPi group and caused delays in the preparation phase of the step in the STN group. Copyright © 2014, Journal of Neurophysiology.
    Full-text · Article · Jun 2015 · Journal of Neurophysiology
  • Source
    • "The uses of dopaminergic drugs or deep brain stimulation do not provide significant improvements of BD, probably due to a neuropathological process spreading towards nondopaminergic pathways [3]. Moreover, previous studies have demonstrated that treatment with levodopa increases postural sway in patients with advanced PD [4]. BD is characterized by alterations of postural control strategies during standing tasks responding to an unexpected destabilizing perturbation or performing voluntary movements [5]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Balance dysfunction (BD) in Parkinson’s disease (PD) is a disabling symptom, difficult to treat and predisposing to falls. The dopaminergic drugs or deep brain stimulation does not always provide significant improvements of BD and rehabilitative approaches have also failed to restore this condition. In this study, we investigated the suitability of quantitative posturographic indicators to early identify patients that could develop disabling BD. Parkinsonian patients not complaining of a subjective BD and controls were tested using a posturographic platform (PP) with open eyes (OE) and performing a simple cognitive task [counting (OEC)]. We found that patients show higher values of total standard deviation (SD) of body sway and along the medio-lateral (ML) axis during OE condition. Furthermore, total and ML SD of body sway during OE condition and total SD of body sway with OEC were higher than controls also in a subgroup of patients with normal Berg Balance Scale. We conclude that BD in Parkinsonian patients can be discovered before its appearance using a PP and that these data may allow developing specific rehabilitative treatment to prevent or delay their onset.
    Full-text · Article · Apr 2015 · Parkinson's Disease
Show more