Trigeminal Nerve Electrophysiological Findings in Hemifacial Atrophy: A Systematic Literature Review and Retrospective Chart Review

Abstract Objective Hemifacial atrophy (HFA) is a rare disorder characterized by progressive unilateral wasting facial soft tissue, muscle, and/or bone. Trigeminal nerve abnormalities may contribute to or result from disease pathophysiology. We aimed to gain further insights into the role of trigeminal pathophysiology along the HFA severity spectrum. Methods A systematic literature review was performed according to PRISMA standards. Retrospective cases of HFA from the literature and Mayo Clinic EMG database were pooled for descriptive and semi-quantitative analysis. Results Overall, 13 total HFA patients were identified through literature and database reviews. Trigeminal nerve testing was abnormal in 9/13 (69%), exclusively in moderate-severe cases. Abnormalities suggested a peripheral (7/9, 78%) or mixed central/peripheral (2/9, 22%) localization. Trigeminal nerve abnormalities were not identified in any of the 4 cases with mild disease severity. Conclusion Moderate to severe cases of HFA were associated with electrophysiological trigeminal abnormalities. No abnormalities were seen in mild cases of HFA. Significance Trigeminal nerve electrophysiology may serve as a biomarker of moderate-severe disease progression, likely reflecting the consequences of progressive soft tissue atrophy.