Which statement best describes the diagnostic approach to Bell palsy?

Which statement best describes the diagnostic approach to Bell palsy?

• A. It is a diagnosis of exclusion characterized by sudden ipsilateral facial weakness involving the forehead, taste disturbance, and inability to close the eyelid
• B. It is confirmed by MRI showing facial nerve enhancement
• C. It presents with bilateral facial weakness
• D. It is caused by a stroke in the brainstem

Answer: (A)

Bell palsy is a peripheral facial nerve palsy that is diagnosed clinically and by exclusion. It typically presents with a sudden onset of unilateral facial weakness that involves the entire side of the face, including the forehead, making it difficult to raise the eyebrow and to close the eye. Taste disturbance on the anterior two-thirds of the tongue may be present due to involvement of the chorda tympani branch. The forehead involvement helps differentiate a peripheral facial nerve problem from a central (upper motor neuron) lesion, which usually spares the forehead because of bilateral cortical innervation. Because other causes—such as stroke, tumors, or Ramsay Hunt syndrome—need to be ruled out, the diagnosis is considered one of exclusion, and imaging is not routinely required to confirm Bell palsy unless red flags or atypical features appear. Bilateral facial weakness or a brainstem stroke would present with different patterns and additional signs, making Bell palsy the best fit for this description.

Bell palsy is a peripheral facial nerve palsy that is diagnosed clinically and by exclusion. It typically presents with a sudden onset of unilateral facial weakness that involves the entire side of the face, including the forehead, making it difficult to raise the eyebrow and to close the eye. Taste disturbance on the anterior two-thirds of the tongue may be present due to involvement of the chorda tympani branch. The forehead involvement helps differentiate a peripheral facial nerve problem from a central (upper motor neuron) lesion, which usually spares the forehead because of bilateral cortical innervation. Because other causes—such as stroke, tumors, or Ramsay Hunt syndrome—need to be ruled out, the diagnosis is considered one of exclusion, and imaging is not routinely required to confirm Bell palsy unless red flags or atypical features appear. Bilateral facial weakness or a brainstem stroke would present with different patterns and additional signs, making Bell palsy the best fit for this description.