Acupuncture for Poststroke Dysphagia: An NTS-Centered Hypothesis-Generating Framework Linking the Brainstem Swallowing Network, Neuroimmune Regulation, and Vagal Anti-Inflammatory Signaling.

Abstract

Background: Poststroke dysphagia (PSD) may reflect not only focal motor pathway injury but also instability of the brainstem swallowing network under neuroimmune, glial, and vascular microenvironmental stress.

Methods: This mechanism-oriented narrative review synthesized evidence on swallowing central pattern generator (CPG) organization, nucleus tractus solitarius (NTS)-related sensory integration within the medullary swallowing network, poststroke neuroinflammation, altered glial responses, blood-brain barrier/neurovascular unit (BBB/NVU) dysfunction, vagus-related anti-inflammatory regulation, and acupuncture-mediated neuromodulation.

Results: Evidence suggests that inflammatory amplification, altered glial responses, and BBB/NVU instability may be associated with reduced reserve in the distributed medullary swallowing network. Within this broader dorsal and ventral swallowing circuitry, the NTS contributes to sensory integration and premotor organization rather than serving as the sole center of swallowing pattern generation. Such disturbances may contribute to respiratory-swallow discoordination in vulnerable patients. Acupuncture and electroacupuncture may indirectly support swallowing-network recovery by modifying inflammatory burden, glial state, autonomic balance, and microenvironmental permissiveness. However, most mechanistic evidence is derived from ischemic stroke models in which swallowing was not the primary outcome.

Conclusion: We propose an NTS-focused, hypothesis-generating framework in which acupuncture may support PSD recovery by modifying neuroimmune, glial, vascular, and autonomic background conditions relevant to brainstem swallowing-network stability. This framework should not be interpreted as evidence that acupuncture directly acts through a confirmed NTS-vagal anti-inflammatory pathway. Future studies should distinguish direct PSD evidence from indirect mechanistic evidence, stratify patients by inflammatory burden and autonomic tone, and incorporate physiological proxies of respiratory-swallow phase stability as mechanistically informative outcomes.