Botulinum Toxin for Chronic Migraine: Beyond Headache Reduction and Toward Possible Cognitive Benefits.

Chronic migraine (CM) is a debilitating neurological disorder characterized not only by persistent and severe pain, but also by substantial cognitive dysfunction that affects attention, working memory, processing speed, and executive functions. These neuropsychological disturbances are likely influenced by overall disease burden and are further modulated by affective comorbidities, sleep disturbances, and medication overuse. OnabotulinumtoxinA (BoNT-A) is an established preventive therapy for CM, supported by strong evidence of both efficacy and safety. This narrative review synthesizes findings from studies examining the relationship between BoNT-A treatment and domain-specific cognitive improvements in CM. It also outlines the potential pathophysiological mechanisms underlying these effects, summarizes the limitations of the existing literature, and highlights priorities for future research. Current evidence suggests that BoNT-A may confer neurocognitive benefits, particularly in working memory and processing speed, and that these improvements may occur partly independently of reductions in headache frequency. These favorable cognitive effects appear to be plausibly linked to decreased nociceptive "noise" and improved cortical inhibition, potentially mediated through modulation of central sensitization, nociceptive signaling, and affective states.