The Electrophysiological Investigation of Higher Level Neural Manifestations of Freezing of Gait in Parkinson's Disease Patient
Condition: Parkinson's Disease; Freezing of Gait
MeSH terms: Parkinson Disease
Study type: Interventional

Summary: 
      We aim to investigate the higher level mechanism of gait disorders in PD patients by
      ambulatory recording of electroencephalographic (EEG) and leg electromyographic (EMG) signals
      during unconstrained walking. Independent component analysis will be conducted for signal
      analysis. The connectivity among different brain regions will also be investigated. The PD
      patients received deep brain stimulation will be recruited for the study. The local field
      potentials recorded from sub-thalamic nuclei and/or PPN will be recorded concomitantly with
      EEG and leg EMG signals during unconstrained walking in PD patients to assess the roles of
      these deep structures in ambulation and their functional connectivity with other brain
      regions during walking.
    

Detailed description: 
      Gait disorder in Parkinson's disease (PD) contains several aspects including particularly the
      slowness of walking and freezing of gait (FOG). These problems may sometimes cause fall of
      patients and culminate in severe head injury and bony fracture. In this regard the
      understanding of freezing of gait and other parkinsonian ambulatory disorders is important
      for the management of patients. Previous electrophysiological studies of gait disorders were
      majorly focused on the kinetic and kinematric measurements. How the higher level neural
      structures including the cerebral cortex, basal ganglia, sub-thalamic nucleus or
      pedunculopontine nucleus were involved in the gait processing are currently unknown. A recent
      study by adopting movement related cortical potential (MRCP) recording to probe the PD
      ambulatory disorders in freezing and non-freezing patients illustrated that PD patients with
      FOG lost the relationship between stride length and the movement related potentials. Since
      the study was performed in constrained condition and each trigger for MRCP did not guarantee
      to be of freezing nature in FOG patients, the results cannot reflect the true manifestations
      of gait freezing in PD patients. In the current proposal, we will perform concomitant
      recording of the scalp electroencephagraphic and leg electromyographic signals during
      unconstrained walking in normal subjects and PD with or without FOG. Independent component
      analysis (ICA) will be conducted for analyzing the possible differences of patterns among the
      three groups and within the FOG patients during the freezing and non-freezing phases. In
      addition, the cortical effective connectivity among different cortical regions during
      freezing and non-freezing phase will also be assessed. Since sub-thalamic nuclei and
      pedunculopontine nucleus may be involved in the ambulatory circuitry, we will also
      investigate this possibility in PD patients to be treated with deep brain stimulation. The
      nuclear local field potentials will be recorded concomitantly with scalp
      electroencephalographic signals and electromyographic signals during unconstrained signals.
      ICA and event related de-synchronization analysis will be conducted to understand the roles
      of these nuclei in walking. The effective connectivity of the deep nuclei and the cortical
      regions will also be assessed to learn the functional set of ambulation. The pioneer
      exploration of the higher level neural manifestations of walking will extend the spectrum
      from conventional kinetic and kinematric gait analysis to peep how the central neural
      circuitry operate in ambulation.
    

Intervention name(s): PK-16CH EXG system
Intervention type(s): Device
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Parkinson's disease; freezing of gait; movement disorders; neuroscience; neural; mechanism