@article{PalmisanoKullmannHanafietal.2022,
  author    = {Palmisano, Chiara and Kullmann, Peter and Hanafi, Ibrahem and Verrecchia, Marta and Latoschik, Marc Erich and Canessa, Andrea and Fischbach, Martin and Isaias, Ioannis Ugo},
  title     = {A fully-immersive virtual reality setup to study gait modulation},
  series = {Frontiers in Human Neuroscience},
  volume    = {16},
  journal   = {Frontiers in Human Neuroscience},
  issn      = {1662-5161},
  doi       = {10.3389/fnhum.2022.783452},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267099},
  year      = {2022},
  abstract  = {Objective: Gait adaptation to environmental challenges is fundamental for independent and safe community ambulation. The possibility of precisely studying gait modulation using standardized protocols of gait analysis closely resembling everyday life scenarios is still an unmet need. Methods: We have developed a fully-immersive virtual reality (VR) environment where subjects have to adjust their walking pattern to avoid collision with a virtual agent (VA) crossing their gait trajectory. We collected kinematic data of 12 healthy young subjects walking in real world (RW) and in the VR environment, both with (VR/A+) and without (VR/A-) the VA perturbation. The VR environment closely resembled the RW scenario of the gait laboratory. To ensure standardization of the obstacle presentation the starting time speed and trajectory of the VA were defined using the kinematics of the participant as detected online during each walking trial. Results: We did not observe kinematic differences between walking in RW and VR/A-, suggesting that our VR environment per se might not induce significant changes in the locomotor pattern. When facing the VA all subjects consistently reduced stride length and velocity while increasing stride duration. Trunk inclination and mediolateral trajectory deviation also facilitated avoidance of the obstacle. Conclusions: This proof-of-concept study shows that our VR/A+ paradigm effectively induced a timely gait modulation in a standardized immersive and realistic scenario. This protocol could be a powerful research tool to study gait modulation and its derangements in relation to aging and clinical conditions.},
  language  = {en}
}
@article{IsaiasBrumbergPozzietal.2020,
  author    = {Isaias, Ioannis U. and Brumberg, Joachim and Pozzi, Nicol{\´o} G. and Palmisano, Chiara and Canessa, Andrea and Marotta, Giogio and Volkmann, Jens and Pezzoli, Gianni},
  title     = {Brain metabolic alterations herald falls in patients with Parkinson's disease},
  series = {Annals of Clinical and Translational Neurology},
  volume    = {7},
  journal   = {Annals of Clinical and Translational Neurology},
  number    = {4},
  doi       = {10.1002/acn3.51013},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235982},
  pages     = {579-583},
  year      = {2020},
  abstract  = {Pathophysiological understanding of gait and balance disorders in Parkinson's disease is insufficient and late recognition of fall risk limits efficacious followup to prevent or delay falls. We show a distinctive reduction of glucose metabolism in the left posterior parietal cortex, with increased metabolic activity in the cerebellum, in parkinsonian patients 6-8 months before their first fall episode. Falls in Parkinson's disease may arise from altered cortical processing of body spatial orientation, possibly predicted by abnormal cortical metabolism.},
  language  = {en}
}
@article{PalmisanoBrandtVissanietal.2020,
  author    = {Palmisano, Chiara and Brandt, Gregor and Vissani, Matteo and Pozzi, Nicol{\´o} G. and Canessa, Andrea and Brumberg, Joachim and Marotta, Giorgio and Volkmann, Jens and Mazzoni, Alberto and Pezzoli, Gianni and Frigo, Carlo A. and Isaias, Ioannis U.},
  title     = {Gait Initiation in Parkinson's Disease: Impact of Dopamine Depletion and Initial Stance Condition},
  series = {Frontiers in Bioengineering and Biotechnology},
  volume    = {8},
  journal   = {Frontiers in Bioengineering and Biotechnology},
  issn      = {2296-4185},
  doi       = {10.3389/fbioe.2020.00137},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200801},
  year      = {2020},
  abstract  = {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.},
  language  = {en}
}