Efficacy of Transcranial Direct Current Stimulation In Parkinson's Disease MCI
Condition: Parkinson Disease
MeSH terms: Parkinson Disease
Study type: Interventional

Summary: 
      The aim of the present study is to investigate the efficacy of prefrontal transcranial Direct
      Current Stimulation (tDCS) on cognitive functions and electrophysiological measures in
      Parkinson's Disease Mild Cognitive Impairment (PD-MCI). The participants will be assigned to
      active and sham groups (1:1) and will receive 10 sessions of tDCS (twice a day) for 5 days.
      The study will also examine if the effects may last for a month. The participants will be
      assigned to active and sham groups (1:1) and will receive 10 sessions of tDCS (twice a day)
      for 5 days. The study will also examine if the effects may last for a month.
    

Detailed description: 
      Parkinson's Disease (PD) is the second most common neurodegenerative disorder. The period
      that apparent cognitive deficits exist without disrupting daily life activities is named as
      Mild Cognitive Impairment (PD-MCI). Treatments were considered to be more efficacious in
      PD-MCI than PD dementia as relatively less permanent changes in cortical structures occured.
      No approved treatments exist in PD-MCI and non-pharmacological treatments are under
      investigation as drugs have considerable amount of adverse effects.

      Event Related Potentials (ERP) measurements have the advantages of providing direct and
      objective evidence of central nervous system functions, imaging of the activity of the
      cortical areas and being unaffected by motor deficits. ERP parameters were found to be
      related to cognitive functions and disrupted in PD and PD-MCI. Thus, ERP parameters were
      suggested to be useful in treatment efficacy assessment.

      Transcranial Direct Current Stimulation (tDCS) is a promising non-invasive brain stimulation
      method. Ameliorating effects of tDCS on cognition and ERPs were observed. Enhancing effects
      of tDCS on some cognitive deficits were also reported in PD.

      Few studies reported the efficacy of both tDCS and physical therapy/cognitive training and
      none assessed the efficacy of tDCS solely, compared to a sham control group. All studies
      assessed the efficacy without using electrophysiological measurements that reflect central
      nervous system functions directly. In this project, the efficacy of tDCS will be compared to
      a sham tDCS group and be assessed with electrophysiological measurements for the first time.

      The study is a double-blind randomized controlled trial. The sample will be consisted of
      twenty six participants diagnosed as having PD-MCI due to Movement Disorders Society Level 2
      criteria. The participants will be assigned to active or sham groups. Then,
      neuropsychological test performances and ERP parameters during Oddball paradigm and
      Continuous Performance Test will be measured. Then, participants will be applied ten active
      or sham sessions of left anodal/right cathodal tDCS over the dorsolateral prefrontal cortex
      (DLPFC). All measurements will be repeated both immediately and 1-month after the
      applications.

      Succinctly, the aim of this project is to assess the effect of ten sessions left anodal/right
      cathodal tDCS over the DLPFC on cognitive functions and electrophysiological parameters in
      PD-MCI.
    

Intervention name(s): Transcranial direct current stimulation
Intervention type(s): Device
Intervention description(s): Participants will receive a total of 10 stimulation sessions on 5 consecutive days (twice a day with 3-4 hours interval). During each session, 2 milliAmpers (mA) of active or sham tDCS will be applied for 20 minutes over the dorsolateral prefrontal cortex (left anodal/right anodal).
Other intervention name(s): tDCS; Direct current stimulation; transcranial electrical stimulation
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Parkinson's Disease; Mild Cognitive Impairment; Transcranial Direct Current Stimulation; Cognitive functions; Electrophysiology; Event related potentials