Stroke: The Daily PANCE Blueprint
A 72-year-old man visits the emergency department with concerns about sudden changes in his facial appearance. He mentions that when he woke up this morning, he noticed the right side of his face seemed "droopy," but everything was normal when he went to sleep last night. His medical history includes coronary artery disease, obesity, and poorly controlled type 2 diabetes. Physical examination reveals asymmetry of the face with flattening of the right nasolabial fold and drooping of the right corner of the mouth. Which of the following findings on the affected side would be most suggestive of a central nervous system lesion rather than a peripheral nerve disorder?
A. Reduced salivation
B. Inability to close the eye completely
C. Heightened sensitivity to tastes
D. Loss of sensation in the external ear canal
E. Preserved movement of the forehead muscles
Answer and topic summary
The answer is E. Preserved movement of the forehead muscles
This patient is presenting with symptoms suggestive of facial paralysis, which could be due to either a central nervous system (CNS) lesion or a peripheral nerve problem such as Bell’s palsy. The key to distinguishing between these two is understanding the pattern of muscle weakness.
In a central lesion (such as a stroke affecting the facial motor cortex or its descending pathways):
- There is preservation of forehead movement on the affected side
- This is due to the bilateral cortical innervation of the upper face
- The lower face is predominantly controlled by the contralateral motor cortex
In contrast, a peripheral lesion (like Bell’s palsy affecting the facial nerve):
- Causes weakness of both the upper and lower face on the affected side
- This results in inability to wrinkle the forehead or raise the eyebrow
Therefore, preserved forehead movement in the presence of lower facial weakness strongly suggests a central (upper motor neuron) lesion rather than a peripheral (lower motor neuron) problem.
Other key points:
- Sudden onset of symptoms can occur in both central and peripheral lesions
- The patient’s risk factors (age, diabetes, cardiovascular disease) increase the likelihood of a stroke, but do not rule out Bell’s palsy
- Further neurological examination and possibly neuroimaging would be necessary to confirm the diagnosis
Incorrect answers:
- Reduced salivation: This would be more indicative of a peripheral lesion affecting the facial nerve, which carries parasympathetic fibers to the salivary glands.
- Inability to close the eye completely: This (lagophthalmos) is typically seen in peripheral facial nerve palsy, not in central lesions.
- Heightened sensitivity to tastes: Altered taste sensation is more commonly associated with peripheral facial nerve disorders, not central lesions.
- Loss of sensation in the external ear canal: This would suggest involvement of the sensory components of the facial nerve, which is more consistent with a peripheral lesion.
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Smarty PANCE Content Blueprint Review:
Covered under ⇒ PANCE Blueprint Neurology ⇒ ⇒
Also covered as part of the Emergency Medicine EOR topic lists
