Transcranial Magnetic Stimulation to Improve Speech in Aphasia

• Number of pictures named on the Boston Naming Test, and naming subtests of the Boston Diagnostic Aphasia Exam [ Time Frame: 2 months and 6 months after the completion of a series of TMS treatments ] [ Designated as safety issue: No ]
  

• Number of words per longest phrase length, propositional speech, BDAE [ Time Frame: 2 months and 6 months after completion of a series of TMS treatments ] [ Designated as safety issue: No ]
  

OBJECTIVE: The purpose of this research is to investigate whether repetitive transcranial magnetic stimulation (rTMS) can improve speech in chronic stroke patients with aphasia. TMS allows painless, noninvasive stimulation of brain cortex (1 cm x 1 cm). Slow (1 Hz) rTMS appears to decrease excitability in the targeted cortical region of interest (ROI) leading to measurable behavioral effects. Chronic aphasia patients have been observed in our fMRI work (and others) to have increased activation in right (R) Broca's and other R language homologues during language tasks. It is hypothesized that suppression of activity in a directly targeted right hemisphere (RH) ROI will have an overall modulating effect on functionally connected elements of the distributed neural network for naming (and propositional speech), and will result in behavioral improvement. Patients are studied with overt naming fMRI brain scan pre-and post-rTMS at the Boston University Center for Biomedical Imaging.

RESEARCH PLAN AND METHODS:

The rTMS treatments in Boston take place at the Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School under the supervision of Alvaro Pascual-Leone, M.D., Ph.D. We plan to study 20 nonfluent aphasia patients (>6 Mo. poststroke). An additional 20 patients will be studied at the Hospital of the University of Pennsylvania, H. Branch Coslett, M.D., who is a P.I. on that subcontract. This is a blinded, randomized, sham-control, incomplete crossover design. Naming and language tests (and overt naming fMRI scans) are obtained pre- and post- rTMS. All fMRI scans are covered under the PI's VA Merit Review Grant.

Treatment Design: Multiple Baseline Language Evaluations (x3) are performed at Entry (Boston Naming Test, BNT; and Boston Diagnostic Aphasia Exam, BDAE). Primary Outcome Measures are BNT; and Naming subtests and Spontaneous Speech (cookie theft picture description) from the BDAE. Naming ability for Snodgrass & Vanderwart (S&V, 1980) pictures is also tested at Baseline. Patients are randomly assigned to receive a series of either Sham rTMS followed by a series of Real rTMS; OR they receive only the series of Real rTMS. The Sham series is identical to the Real, however, no magnetic pulse is emitted from the coil, although the patient hears the same clicking sound emitted from the coil. Due to space limitation here, only the Real rTMS treatment schedule is described.

There are two rTMS Phases: During Phase 1, the single, best RH cortical ROI to suppress with rTMS to improve picture naming, is determined for each patient. Real rTMS (1 Hz, 90% motor threshold) is applied for 10 minutes, in separate rTMS sessions, to each of 4 different RH cortical ROIs (R ant. BA 45; R post. BA 45; R BA 44 and R M1, mouth). S&V Picture Naming is tested immediately before and after each ROI has been suppressed with rTMS. The single RH ROI which is associated with at least a 2 SD improvement (above Baseline S&V Naming), immediately following 10 minutes of rTMS to suppress that cortical area, is considered to be the Best Response ROI for that patient. We have observed that suppression of R post. BA 45 to be the Best Response area in 9 previous aphasia cases. During Phase 2, the Best Response ROI from Phase 1 is suppressed for 20 minutes, 5 days per week, 2 weeks. All patients receive follow-up BNT and BDAE testing at 2 months following the 10th Real (or Sham) rTMS treatment.