舌咽神経・迷走神経・副神経・舌下神経

Glossopharyngeal, Vagus, Accessory, and Hypoglossal Nerves in Head and Neck Practice

舌咽神経，迷走神経，副神経，舌下神経について，頭頸部における解剖と外科的ランドマークについて解説するとともに，各神経の機能とその障害について詳述した。また，具体的な症例について頭頸部外科の観点から提示し，頭頸部領域における各神経の見え方や神経障害に伴う所見を提示した。

Abstract

This review presents a concise, practice-focused overview of the glossopharyngeal (IX), vagus (X), accessory (XI), and hypoglossal (XII) nerves, with particular emphasis on head and neck practice. We outline clinically relevant anatomy and surgical landmarks from the skull base to the cervical field, including constant planes, vascular and osseous reference points, and danger zones encountered during neck dissection, thyroid surgery, and parapharyngeal surgery. We then summarize each nerve's major functions and characteristic deficits, linking sentinel symptoms with bedside and endoscopic findings to expedite localization. Representative cases illustrate intraoperative and imaging appearances and demonstrate how nerve injury manifests on laryngoscopy, swallowing assessment, and shoulder evaluation. By integrating structure, function, and practical signs, this concise overview aims to support safer surgery, clearer differential diagnosis, and targeted rehabilitation in everyday head and neck care.