Phase matters: A role for the subthalamic network during gait

• Published in: PloS one 2018-06, Vol.13 (6), p.e0198691-e0198691
• Main Authors: Arnulfo, Gabriele, Pozzi, Nicolò Gabriele, Palmisano, Chiara, Leporini, Alice, Canessa, Andrea, Brumberg, Joachim, Pezzoli, Gianni, Matthies, Cordula, Volkmann, Jens, Isaias, Ioannis Ugo
• Format: Article
• Language: English
• Subjects: Aged; Basal ganglia; Bioengineering; Biology and Life Sciences; Brain; Computed tomography; Computer and Information Sciences; Data processing; Deep Brain Stimulation; Dementia; Diagnosis; Dopamine; Feedback, Physiological; Female; Frequency dependence; Gait; Gait - physiology; Gait Analysis - methods; Hospitals; Human locomotion; Humans; Informatics; Information processing; Locomotion; Male; Medicine and Health Sciences; Middle Aged; Neostriatum; Nerve Net - physiology; Neural networks; Neurology; Neurons - physiology; Parkinson disease; Parkinson Disease - diagnostic imaging; Parkinson Disease - physiopathology; Parkinson Disease - therapy; Parkinson's disease; Research and Analysis Methods; Robotics; Standing Position; Stimulation; Subthalamic nucleus; Subthalamic Nucleus - cytology; Subthalamic Nucleus - diagnostic imaging; Subthalamic Nucleus - physiology; Surgery; Synchronization; Thalamus; Tomography, Emission-Computed, Single-Photon; Topography; Transcutaneous Electric Nerve Stimulation
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0198691

The role of the subthalamic nucleus in human locomotion is unclear although relevant, given the troublesome management of gait disturbances with subthalamic deep brain stimulation in patients with Parkinson's disease. We investigated the subthalamic activity and inter-hemispheric connectivity during walking in eight freely-moving subjects with Parkinson's disease and bilateral deep brain stimulation. In particular, we compared the subthalamic power spectral densities and coherence, amplitude cross-correlation and phase locking value between resting state, upright standing, and steady forward walking. We observed a phase locking value drop in the β-frequency band (≈13-35Hz) during walking with respect to resting and standing. This modulation was not accompanied by specific changes in subthalamic power spectral densities, which was not related to gait phases or to striatal dopamine loss measured with [123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane and single-photon computed tomography. We speculate that the subthalamic inter-hemispheric desynchronization in the β-frequency band reflects the information processing of each body side separately, which may support linear walking. This study also suggests that in some cases (i.e. gait) the brain signal, which could allow feedback-controlled stimulation, might derive from network activity.