Treating Primary Progressive Aphasia (PPA) Using High-definition tDCS

Summary

This is a double-blind, sham-controlled, crossover study in which subjects with the non-fluent/agrammatic and logopenic variants of primary progressive aphasia (naPPA and lvPPA, respectively) will undergo language testing and structural and functional brain imaging before and after receiving 10 semi-consecutive daily sessions of real or sham high-definition transcranial direct current stimulation (HD-tDCS) paired with modified constraint-induced language therapy (mCILT). Language testing and brain imaging will be repeated immediately after completion of and 3 months following completion of treatment. The 3-month follow-up will be the primary endpoint. The investigators will examine changes in language performance induced by HD-tDCS + mCILT compared to sham HD-tDCS + mCILT. The investigators will also use network science to analyze brain imaging (fMRI) data to identify network properties associated with baseline PPA severity and tDCS-induced changes in performance. This study will combine knowledge gained from our behavioral, imaging, and network data in order to determine the relative degrees to which these properties predict whether persons with PPA will respond to intervention.

Conditions

• Primary Progressive Aphasia

Interventions

DEVICE

high-definition transcranial direct current stimulation

High definition transcranial direct current stimulation (HD-tDCS) involves the application of low-intensity current through electrodes placed on the scalp. It is believed to elicit brain effects by producing incremental shifts in the resting membrane potential of large numbers of neurons, which alters neuronal firing rates and thus modulates patterns of brain activity in potentially behaviorally-relevant ways. HD-tDCS differs from conventional transcranial direct current stimulation (tDCS) because it employed smaller electrodes configured in such a way as to deliver more focal stimulation of the brain.

BEHAVIORAL

modified constraint-induced language therapy

Modified constraint-induced language therapy (mCILT) is a behavioral language therapy that invokes use-dependent learning in communicative interactions by requiring spoken output and restricting use of alternative forms of communication, such as gestures, as a substitute for spoken output. Other key elements of CILT include massed practice of goal-directed speech and shaping of desired responses by increasing response demands as participants improve. MCILT differs from traditional constraint-induced language therapy (CILT) in three ways: 1) it will be done as an individual therapy with the examiner in the role of a communication partner; 2) treatment will be delivered in short sessions (1 hour rather than a more typical 3-4 hour session); 3) targeting nouns + semantically related verbs to generate noun + verb phrases in treatment, a modification that may be better suited to addressing syntactic structure.

Sponsors & Collaborators

• University of Pennsylvania

  lead OTHER

Principal Investigators

• Roy H Hamilton, MD · University of Pennsylvania

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

CROSSOVER

Eligibility

Min Age

45 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-08-17

Primary Completion

2025-06-30

Completion

2025-06-30

FDA Device

Yes

Countries

• United States

Study Locations