TY  - JOUR
A1  - Palmisano, Chiara
A1  - Beccaria, Laura
A1  - Haufe, Stefan
A1  - Volkmann, Jens
A1  - Pezzoli, Gianni
A1  - Isaias, Ioannis U.
T1  - Gait initiation impairment in patients with Parkinson’s disease and freezing of gait
JF  - Bioengineering
N2  - Freezing of gait (FOG) is a sudden episodic inability to produce effective stepping despite the intention to walk. It typically occurs during gait initiation (GI) or modulation and may lead to falls. We studied the anticipatory postural adjustments (imbalance, unloading, and stepping phase) at GI in 23 patients with Parkinson’s disease (PD) and FOG (PDF), 20 patients with PD and no previous history of FOG (PDNF), and 23 healthy controls (HCs). Patients performed the task when off dopaminergic medications. The center of pressure (CoP) displacement and velocity during imbalance showed significant impairment in both PDNF and PDF, more prominent in the latter patients. Several measurements were specifically impaired in PDF patients, especially the CoP displacement along the anteroposterior axis during unloading. The pattern of segmental center of mass (SCoM) movements did not show differences between groups. The standing postural profile preceding GI did not correlate with outcome measurements. We have shown impaired motor programming at GI in Parkinsonian patients. The more prominent deterioration of unloading in PDF patients might suggest impaired processing and integration of somatosensory information subserving GI. The unaltered temporal movement sequencing of SCoM might indicate some compensatory cerebellar mechanisms triggering time-locked models of body mechanics in PD.
KW  - freezing of gait
KW  - gait initiation
KW  - Parkinson’s disease
KW  - posture
KW  - segmental centers of mass
KW  - anthropometric measurement
KW  - base of support
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297579
SN  - 2306-5354
VL  - 9
IS  - 11
ER  - 
TY  - JOUR
A1  - Palmisano, Chiara
A1  - Brandt, Gregor
A1  - Vissani, Matteo
A1  - Pozzi, Nicoló G.
A1  - Canessa, Andrea
A1  - Brumberg, Joachim
A1  - Marotta, Giorgio
A1  - Volkmann, Jens
A1  - Mazzoni, Alberto
A1  - Pezzoli, Gianni
A1  - Frigo, Carlo A.
A1  - Isaias, Ioannis U.
T1  - Gait Initiation in Parkinson’s Disease: Impact of Dopamine Depletion and Initial Stance Condition
JF  - Frontiers in Bioengineering and Biotechnology
N2  - Postural instability, in particular at gait initiation (GI), and resulting falls are a major determinant of poor quality of life in subjects with Parkinson’s disease (PD). Still, the contribution of the basal ganglia and dopamine on the feedforward postural control associated with this motor task is poorly known. In addition, the influence of anthropometric measures (AM) and initial stance condition on GI has never been consistently assessed. The biomechanical resultants of anticipatory postural adjustments contributing to GI [imbalance (IMB), unloading (UNL), and stepping phase) were studied in 26 unmedicated subjects with idiopathic PD and in 27 healthy subjects. A subset of 13 patients was analyzed under standardized medication conditions and the striatal dopaminergic innervation was studied in 22 patients using FP-CIT and SPECT. People with PD showed a significant reduction in center of pressure (CoP) displacement and velocity during the IMB phase, reduced first step length and velocity, and decreased velocity and acceleration of the center of mass (CoM) at toe off of the stance foot. All these measurements correlated with the dopaminergic innervation of the putamen and substantially improved with levodopa. These results were not influenced by anthropometric parameters or by the initial stance condition. In contrast, most of the measurements of the UNL phase were influenced by the foot placement and did not correlate with putaminal dopaminergic innervation. Our results suggest a significant role of dopamine and the putamen particularly in the elaboration of the IMB phase of anticipatory postural adjustments and in the execution of the first step. The basal ganglia circuitry may contribute to defining the optimal referent body configuration for a proper initiation of gait and possibly gait adaptation to the environment.
KW  - gait initiation
KW  - Parkinson’s disease
KW  - basal ganglia
KW  - dopamine
KW  - base of support
KW  - anthropometric measurements
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200801
SN  - 2296-4185
VL  - 8
ER  -