Effects of Transcranial Direct Current Stimulation in Post-stroke Aphasia

Recruiting

Phase 2 Results N/A

Trial Description

This study aims to determine whether transcranial direct current stimulation (tDCS) paired with speech-language therapy is more beneficial than speech-language therapy alone in acute and chronic post-stroke aphasia.

Detailed Description

This study aims to determine whether behavioral word-retrieval therapy coupled with anodal tDCS will improve the fluency and name retrieval performance of participants with post-stroke aphasia more efficiently and for greater duration than language therapy alone (i.e. in the sham condition).
tDCS neuronal targets will be selected in this order:
1. left posterior superior-middle temporal gyrus (an area critical for word retrieval and word comprehension),
2. left posterior frontal areas found to be responsible for lexical selection if the first area is infarcted, or
3. right cerebellum (important for learning, and consistently activated in naming task) if both of the other areas are infarcted.
The same areas will be stimulated during the first tDCS and sham periods. If the participant returns for a second period of tDCS and sham with language therapy, the right cerebellum will be stimulated (if it was the only uninfarcted target area investigators will stimulate this area again). For cerebellar stimulation, either anodal or cathodal will be used as studies show that anodal or cathodal stimulation has an effect on cognitive functions.

Conditions

Interventions

  • Active tDCS plus Speech-Language Therapy Device
    Intervention Desc: 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 not affected by the lesion(perilesional areas, right hemisphere or cerebellum). 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.
    ARM 1: Kind: Experimental
    Label: Active tDCS plus Speech-Language Therapy
    Description: Active tDCS will be applied at the beginning of 45min speech-language therapy session and will last for 20 min. Language therapy will be oral and written naming.
  • Sham plus Speech-Language Therapy Device
    Intervention Desc: 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.
    ARM 1: Kind: Experimental
    Label: Sham plus Speech-Language Therapy
    Description: Sham tDCS will be applied at the beginning of 45min speech-language therapy session. Language therapy will be oral and written naming.

Trial Design

  • Allocation: Randomized
  • Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
  • Purpose: Treatment
  • Intervention: Crossover Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Change in picture naming scores in trained and untrained items Before and after 15 sessions of intervention (3 weeks) and at 2 weeks and 2 months follow-ups No
Secondary Change in Philadelphia Naming Test: Picture naming of everyday objects, different from training set Before and after 15 sessions of intervention (3 weeks) and at 2 weeks and 2 months follow-ups No
Secondary Change in Written naming of objects and actions Before and after 15 sessions of intervention (3 weeks) and at 2 weeks and 2 months follow-ups No
Secondary Change in working memory (digit span) Before and after 15 sessions of intervention (3 weeks) and at 2 weeks and 2 months follow-ups No
Secondary Change in verbal fluency Before and after 15 sessions of intervention (3 weeks) and at 2 weeks and 2 months follow-ups No

Sponsors