The Brain Stimulation and Physical Therapy Study

The Feasibility and Effectiveness of Combining Non-invasive Brain Stimulation and Physical Therapy to Improve Gait and Balance in Older Adults at Risk of Falling

This pilot work will determine the feasibility of tDCS intervention as an effective adjunct intervention to PT aimed at improving gait, balance, and mobility in older adults at risk of falling.

Falls are correlated with both physical and cognitive declines in older adults. Recurrent fallers and those at high risk of falls are often referred to physical therapy (PT) for gait and balance training. Although physical therapists are aware of the importance of cortical control of gait and balance, there is no available tool to directly yet non-invasively intervene brain in the clinical setting. Transcranial direct current stimulation (tDCS) is a noninvasive and safe mean of modulating the excitability of specific brain regions and their connected neural networks. Our group and others have shown that tDCS intervention designed to facilitate the excitability of the left dorsal lateral prefrontal cortex (DLPFC) improves numerous aspects of executive function related to mobility in older adults. However, no studies to date have assessed the feasibility and effectiveness of applying tDCS as an adjunct to PT to improve gait and balance within the geriatric rehabilitation setting. This study aims to 1) assess the feasibility of implementing tDCS prior to each of their first 10 PT sessions, and 2) gather estimates of variability in outcomes related to gait, balance, cognition, and quality of life over time within older adults referred to PT for recurrent falls.

This arm combines tDCS and Physical Therapy intervention. The real tDCS will be delivered before each physical therapy visit for up to 10 combined sessions. The tDCS montage was designed to target the left dorsal lateral prefrontal cortex (DLPFC) for around 20 minutes. The direct current delivered by any electrode will not exceed 2.0 milliamp(mA) and the total amount of current from all electrodes will not exceed 4 mA.

This arm combines sham stimulation and Physical Therapy intervention. The sham stimulation will be delivered before each physical therapy visit for up to 10 combined sessions. We will use an active sham stimulation in which very low-level currents (0.5 mA total) will be transferred between electrodes in close proximity on the scalp throughout the entire 20-minute session. This montage was designed to deliver currents not significantly influence their cortical tissue, but still, mimic the cutaneous sensations induced by tDCS over the same brain site (i.e. left DLPFC).

The participant will receive 20-minute sessions of real tDCS before each physical therapy visit for up to 10 combined sessions, over approximately 6 weeks.

The participant will receive 20-minute sessions of sham stimulation before each physical therapy visit for up to 10 combined sessions, over approximately 6 weeks.

The portion of enrolled participants who complete and adhere to the intervention who complete and adhere to the intervention

Change from baseline in the dual task cost to gait speed (reduced dual task cost after intervention means a better outcome)

The change from baseline in the degree to which performing a secondary cognitive task diminishes gait speed

Change from baseline in the dual task cost to standing postural sway speed (reduced dual task cost after intervention means a better outcome)

The change from baseline in the degree to which performing a secondary cognitive task diminishes the control of standing posture.

Change from baseline in Trail Making Test B - A (reduced time after intervention means a better outcome)

Change from baseline in gradual-onset continuous performance test (gradCPT) ( increased accuracy after intervention means a better outcome)

Change from baseline in Timed Up-and-Go (TUG) (reduced time after intervention means a better outcome)

Change from baseline in Montreal Cognitive Assessment (MoCA) total score (increased score after intervention means a better outcome)

Inclusion Criteria: Ages 65 years old and above Admitted to Physical Therapy for gait and balance training due to the high risk of falls Exclusion Criteria: Inability to stand or walk unassisted for 60 seconds Severe cognitive impairment defined as a Montreal Cognitive Assessment (MoCA) score < 18 Any unstable medical condition Any unstable psychiatric co-morbidity including major depressive disorder, schizophrenia or psychosis Active cancer for which chemo/radiation therapy id being received Significant vision and hearing problems that cannot be corrected with visual and hearing aids Contraindications to tDCS, including seizure within the past two years, use of neuro-active drugs, the risk of metal objects in the brain, implanted medical devices, or the presence of dermatological conditions such as eczema on the scalp.