Pharmacologic Activation of Dormant Cortex in the Restoration of Speech and Language Following Cochlear Implantation in the Deaf
Michael D. Devous, Sr.
UT Southwestern Medical Center, Dallas, TX
David Mahoney Neuroimaging Program
March 2001, for 6 years
Michael D. Devous, Sr.
Professor of Radiology, UT Southwestern Medical Center
Patients with long-standing deafness often have metabolically dormant cortical auditory systems. We hypothesize that pharmacologic stimulation (amphetamine or piracetam) in combination with aural rehabilitation therapy will increase neuronal response to electrical stimulation from cochlear implants and enhance speech perception in cochlear implant patients with long-standing deafness to a greater degree than aural rehabilitation therapy alone.
The goal of this research is to facilitate functional recovery of speech perception in cochlear implant patients. The specific aims are:
1. To delineate blunted or failed responses of the neural circuitry activated during speech perception in patients with cochlear implants who receive either substantial or little benefit from their implants.
2. To determine if the administration of amphetamine or piracetam in concert with aural rehabilitation therapy will enhance recovery of cortical responses to auditory stimuli.
3. To correlate therapy-induced changes in speech perception to pre-treatment functional brain imaging assessments in an attempt to begin defining subjects with favorable prognoses for drug intervention.
Two cochlear implant groups will participate in the study: subjects scoring either >70% or <30% on speech perception tests. They will have initial rCBF SPECT imaging during a control and auditory speech stimulation task (from SPECT rCBF in Language Reception NIH DC 04558). They will receive 10 mg d-amphetamine, 4 mg Piracetam or placebo 20 min prior to intensive aural rehabilitation therapy twice a week for two months. At the completion of therapy, rCBF imaging and speech perception tests will be repeated. Comparison of pre- to post- treatment speech perception measures will be used to assess the efficacy of pharmacologically assisted therapy as our primary outcome measure. Correlation of change in speech perception scores with pre-treatment rCBF data will be used to determine if either resting deficits or blunted responses predict treatment response. Finally, contrasts of pre- and post-treatment rCBF images will provide insight into the mechanism of action of successful treatment.
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