Rehabilitating and Decelerating Language Loss in Primary Progressive Aphasia With tDCS Plus Language Therapy
Condition: Primary Progressive Aphasia; PPA
MeSH terms: Aphasia; Aphasia, Primary Progressive; Pick Disease of the Brain; Frontotemporal Dementia
Study type: Interventional

Summary: 
      People with Primary Progressive Aphasia (PPA) are is a debilitating disorder characterized by
      the gradual loss of language functioning, even though cognitive functioning is relatively
      well preserved until the advanced stages of the disease. There are very few evidence-based
      treatment options available. This study investigates the behavioral and neural effects of
      multiple consecutive tDCS sessions paired with language therapy targeting verbs in sentences
      with individuals with PPA.
    

Detailed description: 
      Primary Progressive Aphasia (PPA) is a debilitating disorder characterized by the gradual
      loss of language functioning, even though cognitive functioning is relatively well preserved
      until the advanced stages of the disease. There are three main PPA variants classified based
      on the pattern of language impairments and areas of atrophy, but anomia is present across all
      variants in the earliest stages. While there is a significant amount of research
      investigating multiple treatment approaches for individuals with aphasia resulting from
      stroke, individuals with PPA have far fewer treatment options to choose from. Recently, a
      growing body of literature of treatment in stroke-based aphasia have found promising results
      for pairing traditional language therapy with non-invasive neurostimulation via transcranial
      direct current stimulation (tDCS). The small amount of studies of the effects of tDCS applied
      to left inferior frontal gyrus (IFG) in PPA also yield promising results that show tDCS can
      enhance generalization to untreated structures. Research in stroke-based aphasia has also
      shown that language outcomes significantly improve when participants are treated with more
      complex language stimuli, because this treatment approach results in enhanced generalization.
      For example, therapy that has participants build sentences around verbs has been found to
      improve word-level verb and noun naming. The current proposal aims to investigate whether
      combining the benefits of tDCS while providing verb retrieval therapy that uses sentence
      building to improve word-level retrieval deficits, will enhance word retrieval deficits in
      PPA and slow the loss of language functioning. It is hypothesized that Furthermore, the
      proposed study will investigate the atrophy patterns at baseline, to determine which atrophy
      patterns are predictive of improved word retrieval. Specifically, this proposal aims: 1) to
      determine whether tDCS to left IFG coupled with therapy promoting verb retrieval within
      sentences improve noun and verb retrieval in treated and untreated items in individuals with
      PPA, and 2) To investigate which patterns of atrophy are predictive of maintenance and
      generalization of word-retrieval in individuals with PPA following tDCS+therapy vs.
      sham+therapy. This proposed research will allow the investigators to evaluate the potential
      benefits and sustainability of tDCS in PPA, the generalization of trained items to untrained
      items, as well as the deceleration of language loss.
    

Intervention name(s): Active tDCS plus Speech-Language Therapy; Sham tDCS plus Speech-Language Therapy
Intervention type(s): Device; Device
Intervention description(s): 1-2 milliamps (mA) of Anodal tDCS stimulation is induced between 5cm X5 cm saline soaked sponges where one sponge is placed on the left inferior frontal gyrus (IFG). The stimulation will be delivered at an intensity of 1-2 mA in a ramp-like fashion for a maximum of 20 minutes. Speech-language therapy will be verb naming therapy in a sentence context.; Sham tDCS stimulation is provided to the left inferior frontal gyrus (IFG) using a tDCS device. Speech-language therapy will be verb naming therapy in a sentence context.
Other intervention name(s): Active tDCS and speech-therapy
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Crossover assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Aphasia; Language therapy; Neurocognitive Disorders; Frontotemporal Dementia; Dementia; Anomia