Bell palsy vs Stroke facial weakness
How to tell Bell palsy and Stroke facial weakness apart when a board question makes them look alike.
Bell palsy affects the whole ipsilateral face; stroke usually spares the forehead and brings other UMN/cortical signs.
Side by side
Bell palsy is peripheral lower motor neuron facial nerve palsy with ipsilateral forehead, eye closure, and lower-face weakness, often with hyperacusis, taste changes, or postauricular pain.
Stroke facial weakness is usually upper motor neuron facial weakness with contralateral lower-face weakness and forehead sparing, often with arm weakness, aphasia, neglect, or other cortical signs.
Peripheral CN VII dysfunction interrupts facial motor output to the entire ipsilateral face.
Corticobulbar tract lesion affects contralateral lower facial muscles more than forehead because upper face receives bilateral cortical input.
Complete ipsilateral facial weakness including forehead and eye closure with no other focal deficits supports Bell palsy.
Forehead sparing, contralateral limb weakness, aphasia, gaze preference, or acute vascular imaging findings support stroke.
The trap
Both can cause facial droop, so forehead movement and associated neurologic deficits decide localization.
Watch it explained
Test it nowThe repair move
For facial droop, test forehead and eye closure before calling it stroke or Bell palsy.
Try a free question
CoreA patient wakes with inability to wrinkle the right forehead, close the right eye, or smile on the right. There is no aphasia, arm weakness, neglect, or sensory loss. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Bell palsy. Complete ipsilateral upper and lower facial weakness without other deficits supports Bell palsy.
Why the other choices are tempting
- B. Stroke facial weakness usually spares the forehead and often has other neurologic signs.
- C. Myasthenia gravis causes fatigable weakness, often ocular/bulbar, not isolated whole-face LMN palsy.
- D. Trigeminal neuralgia causes brief facial pain, not facial weakness.
- E. Cluster headache causes orbital autonomic headache attacks.
Flashcards
Tap a card to flip it.
What facial pattern supports Bell palsy?
Weakness of the entire ipsilateral face including forehead and eye closure supports Bell palsy.
What facial pattern supports stroke?
Contralateral lower facial weakness with forehead sparing supports UMN stroke localization.
Quick answers
What is the fastest way to tell Bell palsy from Stroke facial weakness?
Bell palsy affects the whole ipsilateral face; stroke usually spares the forehead and brings other UMN/cortical signs.
What is the key clue for Bell palsy?
Bell palsy is peripheral lower motor neuron facial nerve palsy with ipsilateral forehead, eye closure, and lower-face weakness, often with hyperacusis, taste changes, or postauricular pain.
What is the key clue for Stroke facial weakness?
Stroke facial weakness is usually upper motor neuron facial weakness with contralateral lower-face weakness and forehead sparing, often with arm weakness, aphasia, neglect, or other cortical signs.
What is the common trap with Bell palsy vs Stroke facial weakness?
Both can cause facial droop, so forehead movement and associated neurologic deficits decide localization.