Tucson Standard

University of Arizona neuroscientists have developed a novel treatment approach for primary progressive aphasia (PPA), a neurological condition characterized by a gradual decline in language abilities. This new method combines traditional speech therapy with noninvasive brain electrical stimulation, specifically transcranial direct current stimulation (tDCS), wherein a low electrical current is applied through electrodes on the scalp.

The researchers' findings, presented in the Journal of Speech, Language, and Hearing Research, suggest that this combined approach may offer more effective management of PPA than speech therapy alone. "Primary progressive aphasia is a condition that causes worsening of communication skills over time. It was identified in the literature only in the last three to four decades, so it is considered pretty new in the health care world – it's still an understudied area," said Katlyn Nickels, the lead researcher and a postdoctoral researcher in the University of Arizona Department of Speech, Language, and Hearing Sciences.

Aneta Kielar, the study's senior author and associate professor in the same department, explained, "While writing and speaking words, people don't just retrieve their meaning. They also retrieve the sound of a word while it is being spoken or written." A specific focus was placed on a type of PPA known as logopenic PPA, where patients struggle with word retrieval and sentence repetition.

The study involved twelve individuals with written language deficits receiving two treatment phases. In one phase, participants underwent speech therapy combined with active tDCS, while in the other phase, the speech therapy was paired with placebo tDCS. The sequence of these treatments was randomized and separated by a two-month interval.

Results showed that although improvements were observed after both treatments, there were more significant and lasting improvements following the phase with active tDCS. Kielar noted, "People who made numerous spelling errors and struggled to frame complete sentences before the treatment were able to form sentences that were grammatically correct, had fewer spelling errors and were more meaningful after treatment."

The researchers attribute the enhanced outcomes to tDCS-induced neuroplasticity. "What that means is that brain stimulation can induce the formation of synapses, the connections between neurons. These connections are important for people's ability to learn and maintain new skills," Kielar stated.

The research team plans to further examine genetic, cognitive, and neural factors influencing PPA recovery, aiming to translate these findings into clinical practice. With tDCS being an inexpensive, safe, and straightforward procedure, Katlyn Nickels emphasized its potential accessibility, saying, "There's a misconception sometimes with neurodegenerative diseases, that once you get a diagnosis, there is nothing that can be done. But we have learned through our research that even when there's a progressive brain disease, we can help restore lost function and even slow down the progression."

This research was supported by several grants awarded to Aneta Kielar, including the Arizona Alzheimer’s Consortium Grant, the Arizona Department of Health Services (018676-00001), the Innovations in Healthy Aging: Grand Challenges of Aging Seed Grant, The University of Arizona Health Sciences (2259304), and the Data Science Academy–Transdisciplinary Research in Principles of Data Science at The University of Arizona (2259910). Additional support came from the Arizona Department of Health Services and the state of Arizona (ADHS Grant No. CTR057001).