Combining tDCS and Neurorehabilitation to Treat Age-related Deficits of Mobility and Cognition: UPfront Walking Study
Condition: Mobility Limitation; Cognitive Impairment
MeSH terms: Mobility Limitation
Study type: Interventional

Summary: 
      Loss of mobility and cognitive ability are serious conditions that threaten the independence
      of older adults. The objective of this study is to initiate a line of research to develop a
      novel therapeutic intervention to enhance both mobility and cognition via neuroplasticity of
      frontal/executive circuits.
    

Detailed description: 
      Frontal lobe dysfunction has been implicated as a factor contributing to gait deficits in
      some individuals with Alzheimer's disease, frontotemporal dementia and vascular dementia.
      There is a critical gap in knowledge about what therapeutic strategies are effective for
      maintaining or reinstating function in this critical brain region in order to preserve
      physical and cognitive health in older adults. The goal of our research is to develop a novel
      therapeutic intervention to enhance both mobility and cognition via neuroplasticity of
      frontal/executive control circuits. The Investigator will engage neuroplasticity of frontal
      circuits in two ways. The first is through neurorehabilitation with "complex walking tasks"
      (CWTs), such as obstacle crossing, obstacle avoidance and walking on non-uniform surfaces.
      CWTs are a potent behavioral approach for engaging prefrontal circuits. Furthermore, CWTs are
      crucial to successful ambulation in the home and community settings and therefore provide an
      ecologically valid therapeutic approach. The second approach that the Investigator will use
      to engage neuroplasticity of frontal circuits is anodal transcranial direct current
      stimulation (tDCS). Anodal tDCS is a safe, non-invasive neuromodulation technique. It has
      previously been shown to induce excitatory effects on brain tissue and, in single-session
      assessments, to improve performance during complex walking tasks. tDCS has also been shown to
      be an effective adjuvant for enhancing the effects of cognitive training. The objective of
      this study is to calculate effect size, establish variance of response and demonstrate
      feasibility of the experimental interventions in order to plan for a full scale clinical
      trial. Participants will include thirty older adults who demonstrate evidence of
      frontal/executive impairment. Participants will be randomized to one of three groups: 1)
      standard walking neurorehabilitation with sham tDCS ('standard/sham' group), 2) complex
      walking neurorehabilitation with sham tDCS ('complex/sham' group), or 3) complex walking
      neurorehabilitation with active anodal tDCS ('complex/active' group). Functional near
      infrared spectroscopy (fNIRS) will be used to explore intervention-induced changes in
      prefrontal cortical activity. Assessments will be conducted at baseline, post-treatment and
      3-month follow up. The Investigator propose the following specific aims:

      Specific Aim 1: Determine preliminary efficacy for recovery of mobility and cognitive
      function.

      Specific Aim 2: Demonstrate feasibility/safety of tDCS as an adjuvant to rehabilitation.

      Specific Aim 3: Explore the relationship between prefrontal activity and behavioral outcomes
      The data collected here will provide the information needed to justify and plan a future full
      scale clinical trial to assess the relative efficacy and underlying mechanisms of each
      intervention approach.
    

Intervention name(s): Neurorehabilitation of Standard Walking; Neurorehabilitation of Complex Walking; Transcranial Direct Current Stimulation (tDCS) dosage A; Transcranial Direct Current Stimulation (tDCS) dosage B
Intervention type(s): Behavioral; Behavioral; Device; Device
Intervention description(s): Neurorehabilitation is a behavioral therapeutic approach for enhancing the neural control of task performance by: Restoration of function, specificity of training, Sensory input to the nervous system, Intensity, Repetition and Progression of training. Neurorehabilitation of standard walking will focus on the use of typical steady state walking.; Neurorehabilitation is a behavioral therapeutic approach for enhancing the neural control of task performance by: Restoration of function, specificity of training, Sensory input to the nervous system, Intensity, Repetition and Progression of training. Neurorehabilitation of complex walking will focus on the use of walking tasks that require increased attention and executive functions. The following walking tasks will be used: over obstacles, navigating around obstacles, changing speeds, on soft surfaces (exercise mat), in dim lighting, while conversing with the therapist, up/down ramps and climbing/descending stairs.; tDCS will be used to induce positive neuromodulation of frontal/executive circuits to make them more amenable to the "activity-dependent neuroplasticity" that is known to occur with behavioral neurorehabilitation. Specifically, tDCS may facilitate the efficacy of our walking neurorehabilitation intervention by strengthening the synaptic connections within the recruited circuits.; tDCS will be used to induce positive neuromodulation of frontal/executive circuits to make them more amenable to the "activity-dependent neuroplasticity" that is known to occur with behavioral neurorehabilitation. Specifically, tDCS may facilitate the efficacy of our walking neurorehabilitation intervention by strengthening the synaptic connections within the recruited circuits.
Other intervention name(s): Soterix Direct Current Stimulator; Soterix Direct Current Stimulator
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants will take part in a 6-week, 18-session neurorehabilitation led by qualified and trained study personnel. Participants will be randomized to one of three groups: 1) standard walking neurorehabilitation with sham tDCS ('standard/sham' group), 2) complex walking neurorehabilitation with sham tDCS ('complex/sham' group), or 3) complex walking neurorehabilitation with active anodal tDCS ('complex/active' group). Training logs will be maintained to gauge the content and intensity of training.
Masking: Double (Participant, Investigator)
Primary purpose: Treatment