Research has found that robotic arm rehabilitation in chronic stroke patients with aphasia may promote speech and language function recovery. Robotic arm rehabilitation is a commonly-used intervention for treating impaired motor function in the arm, wrist, or shoulder subsequent to stroke.
The robotic arm rehabilitation in this study targeted the right arm, as the participants had each suffered a left hemisphere stroke leading to a deficit in motor function on their right side. Individuals with left hemisphere strokes affecting motor function are also likely to have deficits in speech and language processing, and the present study investigated whether those individuals may improve in their speech and language performance following treatment aimed at the domain of motor function. The research team observed small but consistent improvement on measures assessing speech articulation and overall language processing in aphasia.
This research was led Adam Buchwald, associate professor of communicative sciences and disorders at New York University Steinhardt’s School of Culture Education and Human Development, as well as Carolyn Falconer-Horne, a recent PhD graduate of the department.
“While this is an initial finding that should be interpreted cautiously, it remains exciting to consider the possibility that stroke rehabilitation in one domain would improve performance in another domain, said Buchwald. “It remains possible that some treatment approaches encourage plasticity and re-organisation that can span multiple domains, most likely those with similar neural substrates. Further testing of these combined effects could lead to breakthroughs in our approach to stroke rehabilitation for individuals with complex deficits affecting mobility, speech and language processing, and other cognitive domains.”
The research team was assembled following an initial observation by Weill Cornell Medicine’s Dr Dylan Edwards, that participants may be speaking better following 12 weeks of robotic arm treatment. Falconer-Horne, along with Buchwald and Edwards, designed a battery to evaluate possible changes in participant performance that formed the basis of the analyses in this paper.
Objective: This study aimed to determine the extent to which robotic arm rehabilitation for chronic stroke may promote recovery of speech and language function in individuals with aphasia.
Methods: We prospectively enrolled 17 individuals from a hemiparesis rehabilitation study pairing intensive robot assisted therapy with sham or active tDCS and evaluated their speech (N = 17) and language (N = 9) performance before and after a 12-week (36 session) treatment regimen. Performance changes were evaluated with paired t-tests comparing pre- and post-test measures. There was no speech therapy included in the treatment protocol.
Results: Overall, the individuals significantly improved on measures of motor speech production from pre-test to post-test. Of the subset who performed language testing (N = 9), overall aphasia severity on a standardized aphasia battery improved from pre-test baseline to post-test. Active tDCS was not associated with greater gains than sham tDCS.
Conclusions: This work indicates the importance of considering approaches to stroke rehabilitation across different domains of impairment, and warrants additional exploration of the possibility that robotic arm motor treatment may enhance rehabilitation for speech and language outcomes. Further investigation into the role of tDCS in the relationship of limb and speech/language rehabilitation is required, as active tDCS did not increase improvements over sham tDCS.
Adam Buchwald, Carolyn Falconer, Avrielle Rykman-Peltz, Mar Cortes, Alvaro Pascual-Leone, Gary W Thickbroom, Hermano Igo Krebs, Felipe Fregni, Linda M Gerber, Clara Oromendia, Johanna Chang, Bruce T Volpe, Dylan J Edwards