Session Information
Date: Tuesday, June 21, 2016
Session Title: Parkinson's disease: Pathophysiology
Session Time: 12:30pm-2:00pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: We investigated the contribution of the subthalamic nucleus (STN) in gait initiation of subjects with Parkinson’s disease (PD).
Background: Gait initiation is the transient state between standing and walking. The associated motor program is centrally mediated and includes anticipatory postural adjustments (APA) prior to any apparent voluntary movement of the limbs. APA are indicative of the effectiveness of the feedforward control of movement. In PD, the STN shows a predominant β-activity (13-30Hz), which is implicated in rigidity and bradykinesia, and a reduction of β-power is essential for movement execution.
Methods: We recorded Local Field Potentials (LFPs) in the STNs of eight patients by means of the Activa PC+S (Medtronic). Recordings were performed in stimulation-off (for 60 min) and medication-off (overnight suspension of all dopaminergic drugs). Gait initiation was defined with a motion capture system (SIMI) and force plates (Kistler). Subjects stood upright on two force plates and started walking, at a natural (preferred) speed, after a visual cue. Four phases were identified: (i) standing (ST); (ii) anticipatory postural adjustment (APA): from the instant when the centre of pressure starts moving backward and towards the swing (leading) limb to the instant of heel-off of the swing limb (SWho); (iii) gait start (GS): from SWho to toe-off of the stance foot (STto); (iv) walking. STNs were distinguished in STN-contra (contralateral) and -ipsi (ipsilateral) with regards to the swing foot. We computed Power Spectral Density profiles, using Welch method, and β-power of each phase was normalized to the standing condition.
Results: The main and most relevant finding was a β-activity reduction during APA predominantly in the STN-contra (-180%), which showed, in all but two subjects, a strong rebound (+400%) during GS. Of note, the recordings of the STN-ipsi greatly varied among subjects.
Conclusions: Our data suggest a direct involvement of the STN in the feedforward planning of gait initiation, with a predominant involvement of the STN contralateral to the leading foot.
To cite this abstract in AMA style:
C. Palmisano, G. Arnulfo, N.G. Pozzi, A. Canessa, A. Leporini, C.A. Frigo, G. Pezzoli, F. Steigerwald, J. Volkmann, I.U. Isaias. The contribution of the subthalamic nucleus in gait initiation of subjects with Parkinson’s disease [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/the-contribution-of-the-subthalamic-nucleus-in-gait-initiation-of-subjects-with-parkinsons-disease/. Accessed June 14, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/the-contribution-of-the-subthalamic-nucleus-in-gait-initiation-of-subjects-with-parkinsons-disease/