Ongoing Studies

What is Primary Progressive Aphasia (PPA)?

• Language areas of the brain undergo changes, resulting in language impairments. PPA is debilitating because it can affect all aspects of language including, speaking, understanding, reading, and writing.

• PPA impacts one’s communication, leading to social isolation and loss of employment.

• Currently there is no cure for PPA. PPA is a progressive disorder that can expand to other cognitive skills, including attention, memory, and visuospatial skills.

Our previous research indicates that reduced activation and abnormal electrical responses in the frontal and parietal brain regions are associated with early cognitive and language deficits in PPA. 

• Noninvasive neuromodulation techniques have emerged as a possible approach to treat various neurological disorders. Transcranial Direct Current Stimulation (tDCS) is a noninvasive neurostimulation technique that uses weak electric currents to temporarily change activity in the brain’s cells. During tDCS the weak electric current is delivered to the brain through two electrodes placed on the surface of the scalp. tDCS is used in treatment of neurological disorders including depression, chronic pain, tremor in Parkinson’s disease, and epilepsy. Evidence from previous experimental studies suggests that tDCS can successfully improve language functions during subacute and the chronic phases (more than 3 months after stroke) of recovery and in neurodegenerative disorders that affect language functions such as Primary Progressive Aphasia (PPA). The goal of this study is to enhance our understanding of how noninvasive brain stimulation techniques can be used to treat language impairments in PPA and related conditions.

• This current study applies tDCS in combination with speech-language therapy to the regions of the brain that process language and are still structurally intact. 

• The goal is to promote neuroplastic changes in the neurons of the brain to slow the progression of PPA and improve cognitive skills.

What is the purpose of this study?

• The purpose of our study is to learn more about how brain stimulation can be used as a treatment for Primary Progressive Aphasia and other neurodegenerative disorders. In this study we use a transcranial direct current stimulation (tDCS) in combination with language therapy and magnetic resonance imaging to observe brief changes in brain activity prior and immediately following the tDCS.

• We think that “boosting up” speech therapy with brain stimulation can lead to stronger and more lasting benefits.

• We use a personalized evidence based approach, informed by functional neuroimaging and participants’ individual language profile. Structural MRI scans are used to model electrical current flow to enhance accuracy of electrode montage.

• In this new study, we evaluate the effects of tDCS with advanced neuroimaging analyses to gain more insight into the mechanisms of adaptive plasticity and reorganization in the language network.

Treatment of language in Alzheimer’s Disease (AD): A study of neuromodulation and language therapy informed by measures of neurodynamics. In this study, we apply fMRI-guided noninvasive neuromodulation, called Transcranial Direct Current Stimulation (tDCS) to the brain regions that show reduced activation but still are structurally intact in Alzheimer’s dementia. tDCS is paired with personalized speech-language therapy to promote neuroplasticity in the brain circuits targeted neuromodulation. This work is supported by the NIH National Institute of Ageing Arizona via Arizona Alzheimer’s Consortium, Data Science Institute, and Innovation for Healthy Aging Initiative to A. Kielar.

Development of Personalized Non-Invasive Neurostimulation Protocol for Treatment of Language Deficit in Logopenic Primary Progressive Aphasia (PPA). In this study we applied excitatory repetitive transcranial magnetic stimulation (rTMS iTBS) to the left supramarginal gyrus to enhance language processing in three individuals with PPA. rTMS was applied alongside speech-language therapy. The data acquisition was interrupted by COVID-19 mitigation. This work was supported by BIO5 Institute University of Arizona: Team Scholars Program and University of Arizona Core Pilot Facilities Program.

Can the integrity of phonological and semantic systems predict processing of morphological markers in Primary Progressive Aphasia (PPA)? Funded by Innovation for Healthy Aging and Data Science Institute Grants.

Progression of naming deficits in logogenic variant of Primary Progressive Aphasia (PPA) in English and Chinese. This is a longitudinal case study in Bilingual Primary Progressive Aphasia. 

Letter and category fluency as a reflection of naming abilities in chronic post-stroke aphasia. Funded by BIO5 Institute Team Scholars Program research grant and University of Arizona Core Pilot Facilities Program.

Electrophysiological correlates of verb argument structure processing: Can verbs prime their thematic roles? Funded by RII Core Facilities Pilot funding and RDI Faculty seed grant.

Effect of excitatory and inhibitory theta burst stimulation (TBS) to the left Supra Marginal Gyrus on large-scale functional connectivity. This work was supported by BIO5 Institute University of Arizona: Team Scholars Program and University of Arizona Core Pilot Facilities Program. 

Relationship between age-related changes in structural and functional connectivity and cognitive performance. Diffusion weighted imaging and resting state fMRI data is collected from over 60 adults ranging in age from 18-85 years old. All participants completed a comprehensive battery of neuropsychological assessments. Project funded by BIO5 Institute Team Scholars Program research grant and University of Arizona Core Pilot Facilities Program.

Tinnitus and Hyperacusis Treatment: Neuromodulation and active-listening therapy informed by the dynamics of neuroplasticity. This is a clinical-trial combining active listening therapy and noninvasive neuromodulation for the treatment of chronic tinnitus. This is a new and developing research direction. Funding: TBA.