tDCS Intervention in Primary Progressive Aphasia

Summary

Primary progressive aphasia (PPA) is a neurodegenerative disease that affects first and foremost language abilities. Mild cognitive impairment (MCI) is slowly progressive decline in a single domain of cognition (e.g. language) not attributable to motor or sensory loss, without impediment of social or occupational function. MCI can be an early sign of neurodegenerative disease, or can be due to normal aging. When language is the prominent affected domain in MCI, the person may later meet criteria for PPA or may progress to the clinical syndrome of Alzheimer's dementia. Spelling, naming, and working memory (e.g. repetition) are among the language abilities affected early in the course of PPA or language-centered MCI, and different variants have distinct deficits in these domains. This research project investigates the behavioral and neuromodulatory effects of high definition transcranial direct current stimulation (HD-tDCS) during language therapy in PPA participants over time. Anodal HD-tDCS targeting the left inferior frontal gyrus (IFG) administered in combination with language therapy is expected to be more beneficial when compared to language therapy alone. It will 1) improve language performance or decrease rate of decline, 2) have better-sustained effects at 2 weeks and 2 months post-treatment, and 3) produce generalization to untrained language items and some other cognitive functions. Resting-state fMRI, diffusion tensor imaging (DTI), and volumetric data are also collected to investigate changes in functional brain connectivity associated with HD-tDCS in individuals with PPA. A better understanding of the therapeutic and neuromodulatory mechanisms of HD-tDCS as an adjunct to language therapy in PPA may have a significant impact on the development of effective therapies for PPA and MCI, and may offer insight into ways of impeding neurodegeneration that may improve patients' quality of life, as well as extend their ability to work and manage their affairs.

Conditions

• Primary Progressive Aphasia
• MCI
• FTD

Interventions

DEVICE

Active HD-tDCS plus Speech-Language Therapy

Stimulation will be delivered by a battery-driven constant current stimulator. The electrical current will be administered to a pre-specified region of the brain (inferior frontal gyrus). The stimulation will be delivered at an intensity of 2mA (estimated current density 0.04 mA/cm2; estimated total charge 0.048C/cm2) in a ramp-like fashion for a maximum of 20 minutes. Speech-language therapy will be oral and written naming.

DEVICE

Sham plus Speech-Language Therapy

Speech-language therapy will be administered during sham stimulation. Current will be administered in a ramp-line fashion but after the ramping the intensity will drop to 0 mA. Speech-language therapy will be oral and written naming.

Sponsors & Collaborators

• National Institutes of Health (NIH)

  collaborator NIH

• National Institute on Deafness and Other Communication Disorders (NIDCD)

  collaborator NIH

• Johns Hopkins University

  lead OTHER

Principal Investigators

• Kyrana Tsapkini, PhD · Johns Hopkins University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

CROSSOVER

Eligibility

Min Age

50 Years

Max Age

90 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2013-04-30

Primary Completion

2023-07-12

Completion

2023-08-11

Countries

• United States

Study Locations