Session Information
Date: Monday, June 20, 2016
Session Title: Surgical therapy: Parkinson's disease
Session Time: 12:30pm-2:00pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: To investigate the activity of the subthalamic nucleus (STN), and its relation to nigro-striatal dopaminergic denervation, in control of balance in Parkinson’s disease (PD).
Background: Postural instability represents one of the most disabling motor symptoms of PD. Maintenance of postural equilibrium requires muscle activations to counter the gravitational torques acting on the limbs. Stability augmentation entails persistent central nervous system involvement via spinal reflexes, internal model control, and anticipatory postural adjustments. How the central nervous system mitigates the destabilizing effects of neural transmission delays and muscle lags remains unclear. The STN has a major role in the pathophysiology of PD. In these patients, the STN shows a predominant β-activity (13-30Hz) and its reduction is essential for movement execution.
Methods: We recorded Local Field Potentials (LFPs) in the STNs of 7 PD patients by means of Activa PC+S during resting, being the patient comfortably seated, and standing in the upright position, without performing any motor or mental task. Striatal dopaminergic innervation was measured with FP-CIT and SPECT. STNs were distinguished in STN- and +, according to their lower/higher striatal-specific binding ratio. During standing, we measured the centre of pressure and centre of mass displacement by means of two force plates (Kistler) and a motion capture system (SIMI); we also recorded muscular activity of the tibialis anterior and soleus muscles by means of a surface EMG (Zebris). Recordings were performed in stimulation-off (for 60 min) and medications-off (overnight suspension of all dopaminergic drugs) and -on state (at 60 min after 200 mg water soluble levodopa). We computed Power Spectral Density (PSD) profiles, using Welch method, and power relative change (i.e., resting/standing – 1) between the resting and standing conditions.
Results: The main and most relevant finding of our study was a reduction of β-power (>100%) in standing vs. resting in all PD patients. In addition, the STN- showed a higher β-peak in resting when compared to STN+, and a greater modulation of β-power in standing vs. resting (STN-: -205.15%; STN+: -60%, grand mean).
Conclusions: We showed a dopamine-dependent activity of the STN in motor control of postural adjustments during quite standing in subjects with PD.
To cite this abstract in AMA style:
G. Arnulfo, N.G. Pozzi, C. Palmisano, A. Canessa, J. Brumberg, C.A. Frigo, G. Pezzoli, F. Steigerwald, J. Volkmann, I.U. Isaias. A dopamine-dependent activity of the STN in the control of balance in Parkinson’s disease [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/a-dopamine-dependent-activity-of-the-stn-in-the-control-of-balance-in-parkinsons-disease/. Accessed June 14, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/a-dopamine-dependent-activity-of-the-stn-in-the-control-of-balance-in-parkinsons-disease/