Genetic and Neurophysiological Biomarkers of Neuroplasticity Inform Post-Stroke Language Recovery.

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.

• Authors: Haley C Dresang, Denise Y Harvey, Sharon X Xie, Priyanka P Shah-Basak, Laura DeLoretta, Rachel Wurzman, Shreya Y Parchure, Daniela Sacchetti, Olufunsho Faseyitan, Falk W Lohoff, Roy H Hamilton
• Journal: Neurorehabilitation and neural repair (Neurorehabil Neural Repair) Vol. 36 Issue 6 Pg. 371-380 (06 2022) ISSN: 1552-6844 [Electronic] United States
• PMID: 35428413 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Biomarkers
• Brain-Derived Neurotrophic Factor

Topics

• Aphasia (genetics)
• Biomarkers
• Brain-Derived Neurotrophic Factor (genetics)
• Humans
• Language
• Neuronal Plasticity (genetics)
• Stroke (complications, genetics)
• Transcranial Magnetic Stimulation