'Precursory symptoms, awareness or progression of facial palsy' are more useful than 'forehead wrinkling ability' in differentiating central facial palsy examined in the emergency department.

BACKGROUND Forehead wrinkling ability has been considered to be the sign of the central facial palsy (CFP). AIMS/OBJECTIVES To identify characteristics of peripheral FP (PFP) patients in the emergency room (ER), differentiate PFP from central FP (CFP), and assess the utility of forehead wrinkling for this purpose. MATERIALS AND METHODS ER patients with FP were clinically split into PFP (72 patients) and CFP (161 patients) groups. Factors like age, sex, medical history, time from onset to consultation, symptom awareness or progression, precursory symptoms, forehead wrinkling, and imaging history were compared. Multivariate analysis differentiated PFP from CFP, examining misdiagnosis risks based on forehead wrinkling. RESULTS Precursory symptoms and symptom awareness or progression had the highest odds ratios. Some PFP patients could wrinkle their foreheads, typically examined within 1 day of symptoms. PFP patients had more same-day imaging than those assessed a day later. CONCLUSIONS AND SIGNIFICANCE Forehead wrinkling, a traditional CFP sign, is also common in early-stage PFP, decreasing its diagnostic reliability. Patients with solely CFP unable to wrinkle the forehead are very rare at a single institution. Evaluating precursors symptoms, and FP awareness and progression is crucial for differentiation.