A 45-year-old woman presents to the emergency department with a sudden onset of right-sided facial weakness. She reports that the weakness began abruptly this morning and has been progressively worsening. She denies headache, fever, or vomiting. Past medical history is significant for hypertension for which she takes hydrochlorothiazide. Vital signs are within normal limits. On physical examination, she is unable to close her right eye, raise her right eyebrow, or smile on the right side. There is no weakness in her arms or legs, and her speech is normal.
A) Bell palsy
Bell palsy is a lower motor neuron process that presents with sudden-onset unilateral total facial paralysis. This includes the inability to close the eye, raise the eyebrow, or smile on the affected side. Upper motor neuron lesions, such as those seen in strokes, typically spare the forehead due to bilateral innervation.
Answer choice B: Guillain-Barré syndrome, is incorrect. Guillain-Barré syndrome typically presents with ascending muscle weakness and areflexia, not isolated facial paralysis.
Answer choice C: Myasthenia gravis, is incorrect. Myasthenia gravis usually presents with fluctuating muscle weakness that worsens with activity and improves with rest, often affecting the ocular muscles first.
Answer choice D: Stroke, is incorrect. A stroke causing facial paralysis would typically spare the forehead due to bilateral innervation of the upper face by the corticobulbar tract.
Answer choice E: Trigeminal neuralgia, is incorrect. Trigeminal neuralgia presents with severe, episodic facial pain rather than muscle weakness or paralysis.
Key Learning Point
Bell palsy is a lower motor neuron process that presents with sudden-onset of unilateral total facial paralysis. Upper motor paralysis spares the forehead due to bilateral innervation of the forehead.
