Emergency Physicians Differentiate Bell's Palsy From Stroke

A new study shows that emergency department (ED) physicians correctly identify nearly 100% of patients with Bell's palsy, the symptoms of which are almost identical to stroke and brain tumors.

Researchers at Alameda County Medical Center (Oakland, CA, USA) and the University of California, San Francisco (UCSF; USA) conducted a retrospective cohort study of 43,979 patients to evaluate the incidence of potentially incorrect ED diagnoses of Bell’s palsy, and distinguish factors associated with the main outcome measure, the identification of a serious alternative diagnosis at 90 day follow-up.

The results showed that at 90-day follow up, 0.8% of those patients received an alternate diagnosis, such as stroke, intracranial hemorrhage, subarachnoid hemorrhage, brain tumor, central nervous system (CNS) infection, Guillain-Barré syndrome, Lyme disease, otitis media, mastoiditis, or herpes zoster. When restricted to only life-threatening alternative diagnoses associated with central facial paralysis, only 0.3% of the patients were misdiagnosed. The study was published online on July 29, 2013, in the Annals of Emergency Medicine.

“Even lacking established guidelines for diagnosing Bell's palsy, which is the most common cause of paralysis of one side of the face, emergency physicians make the right call nearly every time,” said lead author Jahan Fahimi, MD, MPH. “The combination of thorough history-taking and detailed physical exam allows emergency physicians to determine which patients have a dangerous condition and which can safely be discharged home. While there may be a role for imaging, such as CT or MRI, the overwhelming majority of patients can be evaluated without advanced diagnostic tests.

Patients with Bell's palsy, which affects approximately 15 out of 100,000 people every year, is commonly manifested by partial or complete weakness of the muscles of half of the face, resulting in an inability to raise one eyebrow, wrinkle foreheads, or close one eyelid. Symptoms often progress rapidly and strongly mimic the symptoms of certain types of stroke.

Related Links:
Alameda County Medical Center
University of California, San Francisco