Neuroscience · Year 2 · from Neuroscience
Case 1: Bell's Palsy (Lower Motor Neuron Facial Nerve Palsy)
Patient Presentation
Demographics: 38-year-old female
Chief Complaint: Right-sided facial drooping noticed upon awakening this morning
History of Present Illness: The patient woke up this morning and noticed her face looked "crooked" in the mirror. She cannot close her right eye completely, and the right side of her mouth droops. She has difficulty drinking water as it dribbles out the right side. She noticed some mild pain behind her right ear starting yesterday evening. She denies any arm or leg weakness, speech difficulty (other than from the facial droop), hearing changes, or vision problems. She had a cold with runny nose about a week ago. She has no significant past medical history.
Physical Examination:
- Vital signs: BP 118/72, HR 68, T 36.8C
- General: Anxious appearing female, right facial asymmetry
- Neurological:
- Mental status: Alert, oriented, speech clear but distorted by facial weakness
- Cranial nerves:
- II: Visual acuity and fields normal
- III, IV, VI: Extraocular movements intact; right eye does not close completely when attempting to blink (lagophthalmos); Bell's phenomenon present (eye rolls up when attempting to close)
- V: Facial sensation intact in all three divisions bilaterally
- VII: Right-sided facial paralysis affecting BOTH upper and lower face: unable to raise right eyebrow, unable to close right eye fully, flattened right nasolabial fold, drooping right corner of mouth, cannot puff right cheek
- VIII: Hearing grossly intact; no hyperacusis
- IX, X: Palate elevates symmetrically; gag intact
- XII: Tongue midline
- Motor: 5/5 strength in all extremities
- Sensory: Intact throughout
- Reflexes: 2+ and symmetric
Workup:
- Physical examination findings: Complete right lower motor neuron facial weakness (forehead involved, distinguishing from stroke)
- No imaging required in typical presentation without red flags
- Lyme serology: Obtained given geographic area (endemic); pending
- Glucose: 98 mg/dL (to evaluate for diabetes, a risk factor)
Diagnosis: Bell's palsy (idiopathic peripheral facial nerve palsy)
Treatment:
- Prednisone 60 mg daily for 7 days
- Artificial tears and lubricating ointment for eye protection
- Tape right eye closed at night to prevent corneal exposure
- Valacyclovir 1000 mg three times daily for 7 days (added given within 72 hours of onset)
- Follow-up in 2 weeks
Clinical Course: At 2-week follow-up, the patient showed early signs of recovery with ability to wrinkle her forehead slightly. By 6 weeks, she had recovered approximately 70% of facial movement. At 3-month follow-up, she had nearly complete recovery with only subtle asymmetry when smiling.
Clinical Pearl: Bell's palsy causes lower motor neuron facial weakness affecting the entire hemiface including the forehead. This distinguishes it from upper motor neuron lesions (like stroke), which spare the forehead due to bilateral cortical innervation of the upper face. Most patients (70-80%) recover completely without treatment, but corticosteroids started within 72 hours improve outcomes. Eye protection is critical to prevent corneal ulceration from incomplete lid closure.