CogT BEEM Study (a tDCS Study)
Condition: Mild Cognitive Impairment; Neuropsychiatric Syndrome
MeSH terms: Cognitive Dysfunction
Study type: Interventional

Summary: 
      Co-existing neuropsychiatric symptoms (NPS) in patients with mild cognitive impairment (MCI),
      especially those worsening over time, are associated with more rapid cognitive and functional
      decline and a greater risk of Alzheimer's disease (AD). Optimal NPS management, meaning
      effectively managing multiple NPS simultaneously, requires a solid understanding of the
      shared neural mechanism across NPS. The goal of this proof-of-concept mechanistic
      intervention study is to validate the causal relationship between a NPS-shared neural circuit
      the investigators previously discovered and various NPS. The investigators will modify a key
      region within the NPS-shared neural circuit [i.e. left precentral gyrus (LPG), critical for
      regulating visual attention] with anodal transcranial direct current stimulation (tDCS). Our
      central hypothesis is that an activation of LPG and a reorganization of NPS-shared neural
      circuit will link to improvement in multiple NPS. Using a Stage 0 pilot randomized control
      trial design the investigators will recruit n = 40 older adults with informant-rated NPS that
      has worsened in the past 2 years, which is considered the most detrimental type of NPS in
      MCI. The investigators will assign participants to 4-week active anodal vs. sham LPG online
      tDCS group. The investigators will assess resting-state and visual attention task-related
      functional MRI and informant-rated NPS at baseline, and the end of week 4 and week 8, and
      diffusion MRI at baseline. The two primary aims are to determine the effect of tDCS on
      NPS-shared neural circuit (Aim 1), as well as the relationship between NPS-shared neural
      circuit and informant-report NPS (Aim 2). The exploratory aim will be to examine the
      relationship between NPS and the coherence between structural and functional aspects of the
      NPS-shared neural circuit. Probing the LPG via anodal tDCS provides a way to experimentally
      test the causal relationship between our previously discovered NPS-shared neural circuit and
      informant-rated NPS. The proposed research is highly innovative, while scientifically
      grounded, for targeting one brain region that may affect multiple NPS. Validating the
      hypotheses has the potential for future R01 study that directly conducts a Stage 2 trial
      addressing NPS in MCI, and thus ultimately improves patient's quality of life and reducing
      caregiving burden.
    


Intervention name(s): tDCS
Intervention type(s): Device
Intervention description(s): tDCS (LPG/C3-anode, orbitofrontal cortex/Fp2-cathode) will be administered for 4 weeks (1 session per weekday for 2 weeks, and then 2 sessions per week for 2 weeks, for a total of 14 sessions). All subjects will receive anodal tDCS stimulation for 20 minutes per session, on C3 and the cathode electrode on Fp2 using 10/20 EEG system. tDCS will be applied with a pair of 35 cm2 single-use sponges soaked in approximately 4mL of saline solution on each side (~8mL per sponge) connected to the stimulator. During the 20-minute tDCS session, we will use online tDCS design (i.e., a subject will simultaneously work on the visual attention-oriented task.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Basic Science