Genetic and Neurophysiological Biomarkers of Neuroplasticity Inform Post-Stroke Language Recovery.
Haley C Dresang, Denise Y Harvey, Sharon X Xie and 8 others
PMID 35428413WHAT IT FOUND
In 17 people with chronic post-stroke aphasia, the Val66Val BDNF genotype was linked to milder language impairment than the Val66Met genotype.
Brain responses to stimulation also related to severity, but differently by genotype.
Key findings
01In the regression model, when lesion volume, time post-stroke and age were held constant, Val66Val carriers showed less severe chronic aphasia than Val66Met carriers.
02In post-hoc analysis, the genotype difference was found among participants who were younger at stroke, but not among those who were older at stroke.
03In the model, higher baseline cortical excitability was linked to less severe aphasia in Val66Val carriers and more severe aphasia in Val66Met carriers.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Only 17 participants were analysed, and the authors note the sample was modest for studying genetic effects. One participant was excluded for scoring above the aphasia cutoff, and one was excluded for having two Met alleles, leaving no Met66Met homozygotes in the analysis. All participants were more than 6 months post-stroke, so the findings do not address acute or subacute recovery. The study tested several interaction models in a small sample, and the authors did not combine all predictors in one model because of limited sample size. Time post-stroke and lesion volume showed unequal variance across BDNF groups, so interactions with those variables were not examined.
Declared interests
The authors reported no known conflicts of interest and no significant financial support that could have influenced the work.
The easy way to misread this
Do not use BDNF genotype or transcranial magnetic stimulation responses to make treatment or prognosis decisions. The study analysed only 17 participants and tested several interaction models, so these are exploratory associations rather than a validated clinical test.