Nationwide Analysis of Head and Neck Imaging for Bell's Palsy: Insights From Healthcare Claims

Introduction: Professional society guidelines recommend against routine diagnostic imaging for suspected Bell's palsy at initial presentation. This study examines national trends in imaging use, adherence to guidelines, and the utility of CT and MRI in treatment practices. Methods: A retrospective cohort study of 35,942 adult Bell's palsy patients using ICD-9-CM and ICD-10-CM diagnosis codes from 2016 to 2021 was conducted. These patients were continuously enrolled for ≥ 1 year in the employer-sponsored MarketScan commercial or Medicare outpatient and prescription drugs claims data. The main outcomes of interest were CT and MRI scan usage at or after the diagnosis date. Results: CT scans were performed in 27% of patients (median time: 3 days), while MRI was performed in 25% (median time: 36 days). Within 30 days of their index claim, 16% underwent CT scanning and 12% underwent MRI. Patients on combination therapy (steroids and antivirals) had significantly higher rates of early imaging (CT: 38% vs. 25%, p < 0.001; MRI: 19% vs. 17%, p < 0.001) compared to monotherapy. CT imaging within 30 days of index diagnosis was strongly associated with combination therapy (OR = 3.49, 95% CI = 3.28–3.73, p < 0.001), as was early MRI to a lesser extent (OR = 1.26, 95% CI = 1.17–1.35, p < 0.001). Imaging was most frequent in acute care settings, and median costs rose significantly with dual-modality imaging (p < 0.001). Conclusion: CT and MRI are frequently used in Bell's palsy despite guideline recommendations, especially in patients receiving combination therapy. This study finds an association between diagnostic imaging for Bell's palsy and combination therapy, highlighting opportunities to reduce unnecessary testing and promote guideline-based care. Level of Evidence: 3.