Stimulating Language in Subacute StrokE
Condition: Stroke
MeSH terms: Stroke
Study type: Interventional

Summary: 
      The investigators will study the effects of transcranial direct current (tDCS) stimulation
      during language therapy for naming in individuals with aphasia in the acute and subacute post
      stroke period. Naming difficulties are a persistent and common symptom in aphasia after
      left-hemisphere (LH) stroke. Behavioral therapy (speech and language therapy; SALT) is the
      mainstay treatment for post stroke aphasia. Transcranial direct cortical stimulation (tDCS)
      is a promising adjunct to traditional SALT. tDCS is a safe, non-invasive, non-painful
      electrical stimulation of the brain which modulates cortical excitability by application of
      weak electrical currents in the form of direct current brain polarization. It is usually
      administered via saline-soaked surface sponge electrodes attached to the scalp and connected
      to a direct current stimulator with low intensities. Most studies are conducted in the
      chronic phase after stroke. Because neuroplasticity is greatest early after stroke, there is
      reason to believe tDCS might be most effective in the acute-subacute period. However, only
      two studies have evaluated tDCS paired with language therapy in group studies of acute to
      subacute aphasic stroke patients and only one of these was sham-controlled. Furthermore, no
      studies (of which we are aware) have combined tDCS with therapy to facilitate naming in post
      stroke aphasia, as shown to be effective in studies of chronic stroke. In this study, the
      investigators will evaluate whether tDCS combined with SALT improves naming in individuals
      with aphasia in the acute and subacute post stroke period, more than SALT alone in a
      randomized, double-blind, sham-controlled trial. The investigators will test the hypothesis
      that anodal tDCS (A-tDCS) over a targeted region and computer-delivered SALT is associated
      with greater gains in accuracy in naming pictures, compared to sham combined with the same
      computer-delivered SALT in post stroke aphasia.
    

Detailed description: 
      After informed consent is received, a neurological examination will be performed and multiple
      screening assessments will be conducted including a tDCS and MRI safety screening. If the
      participant passes the initial screening portion, speech and language diagnostic testing will
      be conducted during the same visit (Visit 1). During the next visit (Visit 2), participants
      will undergo a second baseline assessment of naming ability and assessment of connected
      speech. On that visit, participants who have no contraindication for MRI (and agree to have
      MRI) will be randomized to (1) functional magnetic resonance (fMRI) electrode placement or
      (2) structural electrode placement. All participants who have no contraindication will have
      structural and resting state functional connectivity MRI (rsfcMRI). Those randomized to fMRI
      electrode placement will also participate in the naming paradigm during the MRI. The third
      visit will include electrode positioning and tDCS treatment administration. Participants will
      receive 15 sessions (Visits 3-17) of tDCS + SALT administration. At the beginning of Visit 3,
      eligible participants will be randomized to receive either A-tDCS (1 milli amp (mA)) or
      sham-tDCS (placebo) for 15 sessions (20-minutes per each 45-minute behavioral treatment
      session) over the course of three weeks. A computer-delivered naming treatment will be
      coupled with the stimulation. The computer-delivered treatment task will be 45-minutes in
      total length, so that it will commence at the same time as the tDCS administration and
      continue for another 25-minutes after the tDCS has ceased. To assess cardiovascular arousal,
      blood pressure and heart rate will be measured before and after each session. Additionally,
      discomfort ratings will be recorded following the end of each session using the Wong-Baker
      FACES Pain Rating Scale and a weekly neurological exam will be administered by a neurologist.
      Neither the participant nor the clinician monitoring and setting up the treatment will have
      knowledge of the treatment condition (A-tDCS versus sham). Utilizing a computerized picture
      naming assessment, all participants will be assessed at several different time points
      throughout the experiment: twice immediately before and twice the week immediately following
      the fifteenth and final treatment session; twice at five weeks follow-up after the end of
      treatment; and twice at 20 weeks after the end of treatment. Participants who agree to
      participate in the MRI portion of the study (and have none of the additional exclusion
      criteria for MRI) will have structural and rsfcMRI at Visit 2, following the 15th treatment
      session (Week 1 after the end of treatment), and at 5 weeks after the end of treatment.
    

Intervention name(s): A-tDCS (1 mA); SALT; Sham
Intervention type(s): Device; Behavioral; Device
Intervention description(s): 1 mA of A-tDCS stimulation is induced between two 5 cm x 5 cm saline soaked sponges where one sponge (anode: A-tDCS) is placed on the scalp over the targeted cortical region. Ramping up of the current to 1 mA occurs over 10-15 seconds to allow participants to habituate to the tingling sensation. A-tDCS stimulation will be active only in the first 20 minutes of the 45-minute treatment session.; Computer-delivered naming treatment requires matching word (heard and seen being produced by the speaker) with pictures depicting common objects. It is run on a laptop computer with headphones and 2 large response buttons. During treatment, a picture appears on the laptop screen for 2 seconds. Then, a video of the speaker's face below the nose is presented on the screen saying a word that either matches or does not match the picture. The participant is instructed to press a green response button if the word matches the picture and press the red response button if the word does not match the picture.; 1 mA of A-tDCS stimulation is induced between two 5 cm x 5 cm saline soaked sponges where one sponge (anode: A-tDCS) is placed on the scalp over the targeted cortical region. Ramping up of the current to 1 mA occurs over 10-15 seconds to allow participants to habituate to the tingling sensation. Then, the current will be ramped back down to 0 mA in the sham condition. Termination of the stimulation after the ramping up process is generally undetectable, and the brief duration of stimulation yields no functional effects.
Other intervention name(s): Anodal transcranial direct current stimulation; Speech and Language Treatment; Sham-tDCS
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: aphasia, language