Seric Molecular Markers Correlated with Stroke Rehabilitation Outcomes: A Narrative Review

An increasing number of stroke survivors are burdened by persistent disabilities, requiring long-term rehabilitation. However, the extent of functional gain is highly variable, severely impairing patients' quality of life. This variability highlights a critical gap in current prognostic tools, which rely primarily on clinical and neuroimaging data. The aim of this review is to synthesize the current literature on serum biomarkers in stroke survivors and to evaluate their prognostic value for rehabilitation outcomes. Our synthesis indicates that biomarkers reflecting distinct pathophysiological processes are emerging as key prognostic indicators. Markers of inflammation such as Tumor Necrosis Factor-alpha (TNF-α), Interleukin-6 (IL-6), and Interleukin-1 beta (IL-1β), and neuro-glial injury, including S100 Calcium-Binding Protein B (S100B), Neuron-Specific Enolase (NSE), Glial Fibrillary Acidic Protein (GFAP), and Neurofilament Light Chain (NfL), are consistently associated with poorer functional outcomes. Conversely, markers of neuroplasticity, such as Brain-Derived Neurotrophic Factor (BDNF) and Insulin-like Growth Factor-1 (IGF-1), serve as potential indicators of recovery potential, although their predictive accuracy remains inconsistent across studies. Furthermore, emerging biomarkers of synaptic activity, such as Syntaxin-1a (STX1A) and Synaptosomal-Associated Protein, 25kDa (SNAP-25), and neuromuscular junction integrity, such as C-terminal Agrin Fragment (CAF), offer novel insights into brain-periphery communication, though their clinical utility is still under investigation. While promising, the translation of these biomarkers into clinical practice is hindered by methodological limitations, including assay heterogeneity and lack of large-scale validation. Future standardization of these molecular signatures is a critical step toward implementing precision medicine in stroke rehabilitation.