Pre-therapy Neural State of Bilateral Motor and Premotor Cortices Predicts Therapy Gain After Subcortical Stroke: A Pilot Study.

The study included only 10 stroke survivors, so the correlations are preliminary and may not generalise. It was a pilot without a control therapy group, so it cannot prove the training caused improvement or that brain markers predict response. Participants were in the chronic phase, could follow commands, and did not have apraxia, cognitive impairment, or severe receptive aphasia, so results may not apply to acute or subacute stroke or to patients with communication or cognitive limitations. Multiple brain regions and biomarkers were tested in a small sample, increasing the chance of false-positive correlations. The study did not assess whether the mean Fugl-Meyer change of 3.9 points was clinically meaningful, and it notes that meaningful improvement would be greater than 4 points. Prior therapy was not recorded, so patients may have already achieved some improvement before the study. Patients were taking anti-hypertensive, cholesterol-lowering, and/or antiplatelet medications, and the paper does not report whether these influenced gains. Magnetic resonance spectroscopy would need more work and standardisation before it could be used across hospitals.

The study was funded by the American Heart Association. The Hoglund Brain Imaging Center was supported by a gift from Forrest and Sally Hoglund and by National Institutes of Health grants. The authors declared no conflict of interest and no financial benefits.

Do not use these brain chemical measures to decide who gets therapy. The study had only ten patients, was a pilot, and did not test a clinical prediction rule, so the correlations may not hold in practice.