Ontology highlight
ABSTRACT: Background
There is high variability in post-stroke aphasia severity and predicting recovery remains imprecise. Standard prognostics do not include neurophysiological indicators or genetic biomarkers of neuroplasticity, which may be critical sources of variability.Objective
To evaluate whether a common polymorphism (Val66Met) in the gene for brain-derived neurotrophic factor (BDNF) contributes to variability in post-stroke aphasia, and to assess whether BDNF polymorphism interacts with neurophysiological indicators of neuroplasticity (cortical excitability and stimulation-induced neuroplasticity) to improve estimates of aphasia severity.Methods
Saliva samples and motor-evoked potentials (MEPs) were collected from participants with chronic aphasia subsequent to left-hemisphere stroke. MEPs were collected prior to continuous theta burst stimulation (cTBS; index for cortical excitability) and 10 minutes following cTBS (index for stimulation-induced neuroplasticity) to the right primary motor cortex. Analyses assessed the extent to which BDNF polymorphism interacted with cortical excitability and stimulation-induced neuroplasticity to predict aphasia severity beyond established predictors.Results
Val66Val carriers showed less aphasia severity than Val66Met carriers, after controlling for lesion volume and time post-stroke. Furthermore, Val66Val carriers showed expected effects of age on aphasia severity, and positive associations between severity and both cortical excitability and stimulation-induced neuroplasticity. In contrast, Val66Met carriers showed weaker effects of age and negative associations between cortical excitability, stimulation-induced neuroplasticity and aphasia severity.Conclusions
Neurophysiological indicators and genetic biomarkers of neuroplasticity improved aphasia severity predictions. Furthermore, BDNF polymorphism interacted with cortical excitability and stimulation-induced neuroplasticity to improve predictions. These findings provide novel insights into mechanisms of variability in stroke recovery and may improve aphasia prognostics.
SUBMITTER: Dresang HC
PROVIDER: S-EPMC9133188 | biostudies-literature | 2022 Jun
REPOSITORIES: biostudies-literature
Dresang Haley C HC Harvey Denise Y DY Xie Sharon X SX Shah-Basak Priyanka P PP DeLoretta Laura L Wurzman Rachel R Parchure Shreya Y SY Sacchetti Daniela D Faseyitan Olufunsho O Lohoff Falk W FW Hamilton Roy H RH
Neurorehabilitation and neural repair 20220415 6
<h4>Background</h4>There is high variability in post-stroke aphasia severity and predicting recovery remains imprecise. Standard prognostics do not include neurophysiological indicators or genetic biomarkers of neuroplasticity, which may be critical sources of variability.<h4>Objective</h4>To evaluate whether a common polymorphism (Val<sup>66</sup>Met) in the gene for brain-derived neurotrophic factor (BDNF) contributes to variability in post-stroke aphasia, and to assess whether BDNF polymorphi ...[more]