Treating Intention In Aphasia: Neuroplastic Substrates

• Lateralization of Frontal Lobe (and Posterior Perisylvian) Activity During Word Production [ Time Frame: immediately post-treatment scan minus pre-treatment baseline scan ] [ Designated as safety issue: No ]
  Functional MRI laterality indices (LIs)were calculated for lateral frontal, medial frontal, and posterior perisylvian cortex regions of interest (ROIs): L=number of active voxels in left hemisphere ROI and R=number of active voxels in right hemisphere ROI using the following formula: (L-R)/(L+R). LIs could vary from -1 (completely right lateralized) to +1 (completely left lateralized). Then, change in LIs was calculated by subtracting the pre-treatment from the post-treatment and 3-mo follow-up LI. It was expected the intention manipulation would show a rightward shift in LI.
  
  

• Picture Naming Probe Scores (% Accuracy) [ Time Frame: trend for time series of 8 baseline + 30 treatment sessions ] [ Designated as safety issue: No ]
  Improvement for the time series from 8 baseline sessions through 30 treatment sessions for naming probes was computed with the C statistic using Tryon's (1982, 1983) formula for each subject. C statistics were converted to Z scores, using the formula provided by Tryon (1982). Z scores indicated treatment change for each subject, with a positive and significant Z score indicating substantive treatment gains. Z scores were then compared between groups with a t statistic. It was expected that the intention manipulation would lead to greater treatment gains than when it was not used.
  
  
• Category Member Generation Probe Scores (% Accuracy) [ Time Frame: trend for time series of 8 baseline + 30 treatment sessions ] [ Designated as safety issue: No ]
  Improvement for the time series from 8 baseline sessions through 30 treatment sessions for naming probes was computed with the C statistic using Tryon's (1982, 1983) formula for each subject. C statistics were converted to Z scores, using the formula provided by Tryon (1982). Z scores indicated treatment change for each subject, with a positive and significant Z score indicating substantive treatment gains. Z scores were then compared between groups with a t statistic. It was expected that the intention manipulation would lead to greater treatment gains than when it was not used.
  
  

A new treatment manipulating intention substrates for language production in "nonfluent" aphasia patients was developed. The intention component involves initiating word-finding trials with a complex left-hand movement. The study addresses (1) whether or not the intention manipulation (complex left-hand movement) makes a unique contribution to treatment outcome and (2) whether or not the intention manipulation helps to shift word production mechanisms from the left to the right frontal lobe. All study participants take part in functional magnetic resonance imaging (fMRI) scans of word-finding before and after treatment and at 3-month follow-up to measure changes in lateralization of frontal lobe activity during word finding. Only patients with a substantial degree of left frontal activity on the pre-treatment fMRI scan can participate. There are three specific aims: (1) to determine if repetitive initiation of word production with a complex left-hand movement leads to increased right-hemisphere lateralization of frontal activity and if these changes can be attributed to the intention component of treatment, (2) to determine whether activity in posterior perisylvian cortices that is entrained to right frontal activity shows a greater increase in right-hemisphere lateralization from pre- to post-treatment fMRI when the intention component is included in treatment, and (3) to determine whether onset of hemodynamic responses (HDRs) in right motor/premotor cortex becomes more closely associated with the temporal onset of participants' spoken responses across treatment when the intention component is included in treatment. If successful, the treatment can provide a new treatment vehicle for increasing language function in patients with "nonfluent" aphasia.