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Using fNIRS to characterize resting state functional connectivity in people with aphasia and analyze their response to therapy
Poster Session C, Saturday, September 13, 11:00 am - 12:30 pm, Field House
This poster is part of the Sandbox Series.
Voss Neal1, Erin L. Meier2, Lindsey Kelly1, Melissa D. Stockbridge1; 1Johns Hopkins School of Medicine, 2Northeastern University
Prior studies have highlighted the importance of the right hemisphere homologous language network in aphasia recovery, particularly in the subacute-to-chronic phase. We developed a telemedicine-delivered therapy engaging diverse right hemisphere-dominant skills to target nouns and verbs within utterances in people with aphasia (PWA), called “PICTURE-IT.” Our team has utilized telemedicine-based therapy previously through an anomia treatment targeting lexical skills called “CoDeLT.” Given recent support for the use of network-level analysis to investigate post-stroke language impairment and limitations of fMRI, we conducted a preliminary examination of the utility of functional Near-Infrared Spectroscopy (fNIRS) for measuring PICTURE-IT’s impact. First, we compared pre-treatment fNIRS-derived resting state functional connectivity (rs-FC) in PWA to age-matched controls. Subsequently, we explored how pre-treatment rs-FC related to therapy outcomes. Fifteen neurologically healthy older adults (11 men, 4 women; mean age: 58.9 +/- 17.4 years) were compared with two PWA who had received fNIRS in the randomized cross-over trial of PICTURE-IT versus an established naming treatment, CoDeLT. Inclusion in the trial required deficits on either a noun or verb naming test, and the primary outcome was pre- to post-therapy change in noun naming. PWA1 was a 55-year-old right-handed man with a subacute bilateral (left>right) thalamic stroke who received PICTURE-IT then CoDeLT. PWA2 was a 49-year-old right-handed man with a chronic right temporal ischemic stroke who received CoDeLT then PICTURE-IT. fNIRS optodes were positioned over bilateral perisylvian regions resulting in 46 long and 8 short channels. Channels over ventral and dorsal regions within each hemisphere were averaged pairwise across two sequential runs. Data were preprocessed in NIRS Toolbox (Santosa et al., 2018), and channel-wise rs-FC was computed using a prewhitening, robust-fit Pearson correlation routine. Bayesian Tests of Deficit (Crawford & Garthwaite, 2007) were used to evaluate group differences in rs-FC. PWA1 exhibited significantly higher right intra-hemispheric dorsal FC (Z=2.66, [CI: 1.57, 3.77], p=0.022) and lower ventral inter-hemispheric FC (Z=-2.28, [CI: -3.27, -1.32], p=0.044) than controls. He demonstrated a 27% improvement on the BNT following PICTURE-IT (near ceiling), and only a 3% increase following CoDELT. PWA2 also exhibited higher right intra-hemispheric dorsal FC (Z=2.30, [CI: 1.32, 3.30], p=0.042) and lower ventral inter-hemispheric FC (Z=-3.58, [CI: -4.99, -2.14, p=0.004) than controls. PWA2 exhibited a numerical trend toward lower intra-hemispheric left ventral FC (Z=-1.98, [CI: -2.84, -1.10, p=0.075). He demonstrated a modest but better response to CoDeLT (17%) than the right-hemisphere engaging PICTURE-IT (3%). Despite both PWA demonstrating similar fNIRS rs-FC patterns compared to controls at pre-treatment, they exhibited opposite trends of therapeutic benefit. These findings align with the notion that therapies engaging RH regions may be most beneficial in earlier stroke recovery phases. Future directions include expanding the number of participants and evaluating pre- to post-treatment changes in rs-FC. Crawford, J. R., & Garthwaite, P. H. (2007). Comparison of a single case to a control or normative sample in neuropsychology: Development of a Bayesian approach. Cognitive Neuropsychology, 24(4), 343–372. https://doi.org/10.1080/02643290701290146 Santosa, H., Zhai, X., Fishburn, F., & Huppert, T. (2018). The NIRS Brain AnalyzIR Toolbox. Algorithms, 11(5), 73. https://doi.org/10.3390/a11050073
Topic Areas: Speech-Language Treatment,