Need for Routine Brain Magnetic Resonance Imaging for Unilateral Facial Palsy in Emergency Department

Area of Science:

• Neurology
• Radiology
• Emergency Medicine

Background:

• Unilateral facial palsy diagnosis in the emergency department (ED) often involves debate regarding the necessity of routine brain magnetic resonance imaging (MRI).
• Identifying patients who may benefit from advanced imaging is crucial for efficient diagnostic strategies.

Purpose of the Study:

• To evaluate the diagnostic yield of brain MRI in adult patients presenting with unilateral facial palsy in the ED.
• To identify clinical risk factors associated with non-idiopathic causes of facial palsy to guide selective imaging.

Main Methods:

• A single-center, retrospective study analyzed 436 adult patients with unilateral facial palsy as the primary symptom from January 2020 to December 2022.
• Patients with other neurological abnormalities or those not undergoing brain MRI were excluded.
• Positive MRI findings were defined as brain lesions causally related to facial palsy.

Main Results:

• Only 3.0% of patients (13 out of 436) showed positive MRI findings indicative of diagnoses other than Bell's palsy (e.g., stroke, tumor).
• The majority (97.0%) were diagnosed with Bell's palsy.
• A history of transient ischemic attack/stroke and malignancy was significantly higher in patients with non-idiopathic facial palsy.

Conclusions:

• Routine brain MRI for clinically isolated unilateral facial palsy in the ED has a low diagnostic yield.
• Malignancy or prior transient ischemic attack/stroke history are associated with alternative diagnoses.
• A selective imaging strategy guided by risk factors could enhance diagnostic efficiency and patient safety.