TAU: Non-Invasive Brain Stimulation of Elderly Is Expected to Improve Mobility and Reduce the Risk of Falls

Tel Aviv University researchers, under the leadership of Prof. Jeffrey Hausdorff of the Sackler Faculty of Medicine, the Sagol School of Neuroscience, and the Tel Aviv Sourasky Medical Center, and Dr. Brad Manor at Harvard Medical School examined the effects of non-invasive, gentle brain stimulation on the capability of older adults to walk or stand while simultaneously carrying out a cognitive task, a common dual-task situation that can determine their overall functionality.

The researchers stimulated the dorsal lateral pre-frontal cortex (DLPFC), a cognitive brain area responsible for dividing attention and executive functions. They found that this stimulation significantly reduced the immediate, negative impact of a dual task of standing and walking performance.

Prof. Hausdorff said, “We hope that a series of treatments will lead to similar positive results over a more extended period. This therapy method is entirely safe, and we hope that, in time, patients will be capable of treating themselves in their own homes.”

The study team included investigators from Harvard University, research and medical institutions in the U.S. and Spain, and the Tel Aviv Sourasky Medical Center (Ichilov). The study was published in the Annals of Neurology, the journal of the American Neurological Association. The research was funded by a grant from the U.S.-Israel Binational Science Foundation.

Prof. Hausdorff said, “Dual tasking that involves walking while simultaneously carrying out a cognitive task, like talking on a cell phone or with a companion, occurs frequently throughout the day. The concurrent performance of two tasks requires the ability to split attention. We know that among older people, difficulties performing another task while walking or standing reflect an existing and/or a potential problem concerning both functions, as well as an increased risk of falling. A fall can have many severe and undesirable consequences for older adults. We sought to examine the benefits of very low intensity, non-invasive electrical stimulation of various parts of the brain, hoping that this might improve their ability to perform both tasks simultaneously in a safer manner. ”

The study cohort included 57 subjects over the age of 70. Each of them was tested by four different treatments: sham, designed not to have any influence at all, but to rule out any placebo effects; stimulation of a cognitive area of the brain (DLPFC) that is responsible for dividing attention; stimulation of a sensory-motor area of the brain which contributes to the regulation of walking; and simultaneous stimulation of both areas – motor and cognitive – together. Each treatment included non-invasive stimulation using a very low-intensity electric current for 20 minutes. Immediately upon the conclusion of the treatment, the walking and standing sway of each subject were evaluated, with and without the request to also perform a cognitive task.

The study showed that stimulation of the cognitive area, whether alone or together with the stimulation of the motor area, reduced the negative effects of the cognitive task on walking and standing stability by about 50%. On the other hand, stimulation of the sensory-motor area alone and sham stimulation did not improve the subjects’ performance. The investigators explain that, since the stimulation is a gentle one, it does not activate brain neurons but only increases their excitability; in other words, it facilitates the ability of the patient to activate those neurons in his or her brain.

Prof. Hausdorff summarized: “In our study, we demonstrated that a low-level, gentle stimulation of a specific cognitive area of the brain can improve the performance of older adults when they carry out the double task of walking or standing in place while at the same time performing a cognitive task, at least within the immediate time range. Healthy young adults frequently walk while doing many other things; for older adults, however, this may place them in an unsafe situation and increase their risk of falling. We hope that a series of treatments will lead to similar positive results over a more protracted period: to improve standing stability and walking capability, diminish the risks of falling, and perhaps also enhance cognitive function among the elderly population. This treatment is safe, and we hope that, in time, people will be able to undergo self-treatment in their own homes. Additionally, we foresee the possibility of combining this type of therapy with exercise and other modes of intervention that can help to improve walking, to enhance thinking, and to reduce the risk of falls. There is evidence that combined therapy could prove to be the most effective solution, but further research is required to examine this.”