Communication Bridge™-2 (CB2): an NIH Stage 2 randomized control trial of a speech-language intervention for communication impairments in individuals with mild to moderate primary progressive aphasia

Abstract

Background: Primary progressive aphasia (PPA) is a clinical dementia syndrome. Impairments in language (speaking, reading, writing, and understanding) are the primary and persistent symptoms. These impairments progress insidiously and devastate communication confidence, participation, and quality of life for persons living with PPA. Currently, there are no effective disease modifying treatments for PPA. Speech-language interventions hold promise for mitigating communication challenges and language symptoms. However, evidence regarding their efficacy in PPA is of low quality and there are currently no rigorous randomized trials.

Method: Communication Bridge™-2 (CB2) is a Stage 2, superiority, single-blind, randomized, parallel group, active-control, behavioral clinical trial delivered virtually within a telehealth service delivery model to individuals with PPA. Ninety carefully characterized participants with clinically confirmed PPA will be randomized to one of two speech-language intervention arms: (1) Communication Bridge™ a dyadic intervention based in communication participation therapy models that incorporates salient training stimuli or (2) the control intervention a non-dyadic intervention based in impairment therapy models addressing word retrieval and language production that incorporates fixed stimuli. The superiority of Communication Bridge™ over the Control arm will be evaluated using primary outcomes of communication confidence and participation. Other outcomes include accuracy for trained words and scripts. Participants complete two therapy blocks over a 12-month period. Outcomes will be measured at baseline, at each therapy block, and at 12 months post enrollment.

Discussion: The CB2 trial will supply Level 2 evidence regarding the efficacy of the Communication Bridge™ intervention delivered in a telehealth service delivery model for individuals with mild to moderate PPA. An important by-product of the CB2 trial is that these data can be used to evaluate the efficacy of speech-language interventions delivered in both trial arms for persons with PPA. The impact of these data should not be overlooked as they will yield important insights examining why interventions work and for whom, which will advance effectiveness trials for speech-language interventions in PPA.

Trial registration: ClinicalTrials.gov NCT03371706 . Registered prospectively on December 13, 2017.

Keywords: Alzheimer’s; Aphasia; Behavioral intervention; Communication; Dementia; Dyadic intervention; Frontotemporal dementia; Language; Primary progressive aphasia; Randomized clinical trial; Speech; Speech-language pathology; Telehealth; Therapy.

Fig. 1

SPIRIT figure of study timeline. Note: CP, Communication Partner. * For additional details of the screening and enrollment procedures see Tables 1 and 2 in the study protocol. ** The randomization scheduled requires knowledge of the primary progressive aphasia subtype and thus allocation occurs following the baseline assessment 1 visit. *** Control and experimental intervention arms run in parallel.