Ann Hum Biol. 2026 Dec;53(1):2709422. doi: 10.1080/03014460.2026.2709422. Epub 2026 Aug 13.
ABSTRACT
BACKGROUND: Stroke is a leading cause of death and disability worldwide, with 35-80% of survivors developing cognitive impairment that affects quality of life. Current diagnostic tools are limited, highlighting the need for objective, cost-effective biomarkers for post-stroke cognitive impairment (PSCI).
AIM: To investigate the relationship between PSCI severity and sensorimotor evoked potentials, compare interhemispheric sensorimotor cortex excitability, and assess the utility of these potentials for PSCI screening.
SUBJECTS AND METHODS: Twenty-two stroke patients underwent neuropsychological and clinical evaluations at 3-6 months post-stroke, with testing performed within 7±3 days of the scheduled date. Patients were divided into mild cognitive impairment (MCI) and dementia groups. Motor evoked potentials (MEP) elicited by single-pulse transcranial magnetic stimulation assessed primary motor cortex excitability, while somatosensory evoked potentials (SEP) from median nerve stimulation evaluated primary somatosensory cortex excitability.
RESULTS: MEP absence showed a dose-dependent relationship with cognitive severity (Kendall's tau-b = -0.467, p = 0.029); 80% of MEP-absent patients had dementia versus 20% of MEP-present cases. In hemispheric analysis, affected hemispheres displayed elevated the resting motor threshold (RMT) (p < 0.001) and prolonged SEP N20 latency (p < 0.05), while unaffected hemispheres showed increased RMT in the MCI-with-MEP and dementia-without-MEP groups (p < 0.05), with reduced amplitude in dementia-with-MEP patients (p < 0.01). No linear SEP-cognition relationship emerged.
CONCLUSIONS: PSCI severity correlates with MEP presence/absence, not SEP measures. Notably, the excitability of the unaffected motor cortex progressively declines with worsening cognition. Although MEP shows promise as a biomarker for cognitive impairment assessment, longitudinal validation is needed to confirm its predictive utility.
PMID:42593026 | DOI:10.1080/03014460.2026.2709422