Facial Nerve Dysfunction: Evaluation and Natural History

Abstract To review key concepts in facial nerve anatomy, physiology, injury mechanisms, and recovery patterns, and to summarize current approaches to classification, evaluation, and management of facial nerve dysfunction following skull base surgery. Narrative review of anatomical, clinical, and evaluative frameworks relevant to facial nerve dysfunction. Academic and clinical contexts involving the assessment and management of facial nerve injury, with emphasis on skull base surgery. Not applicable; this is a literature-based review. Descriptions of facial nerve anatomy and microanatomy; established classification systems for facial nerve injury; mechanisms of injury; patterns of recovery; common clinical presentations of post-surgical facial paralysis; and current grading scales and evaluation protocols. The review synthesizes foundational anatomical principles with contemporary understanding of facial nerve injury and recovery. It outlines the full spectrum of clinical outcomes observed after facial nerve injury, including typical post-surgical paralysis patterns and their natural course. Commonly used facial paralysis grading scales are compared, and standardized evaluation strategies are highlighted to promote consistent assessment across providers. Taken together, the findings provide a comprehensive framework for understanding and evaluating facial nerve dysfunction following skull base surgery. Understanding and treating facial nerve dysfunction requires nuanced knowledge of anatomy, injury mechanisms, recovery trajectories, and standardized evaluation methods. Consolidating these elements offers valuable guidance for skull base surgeons, facial plastic surgeons, and other clinicians caring for patients with facial paralysis, and supports more consistent and informed clinical decision-making.