Question

The characteristic feature of Horner's syndrome is

• A. Dilated pupil
• B. Ptosis
• C. Increased sweating
• D. Abducted eye

Hint:

Horner's syndrome is a loss of sympathetic tone, so its features are the opposite of pupil dilation and increased sweating.

Answer 1

The Correct Option is B

This question asks for the classic feature of Horner's syndrome, caused by loss of sympathetic supply to the eye and face.

1. Dilated pupil: Loss of sympathetic tone actually causes a constricted pupil (miosis), not dilation.
2. Ptosis: Loss of sympathetic input to Muller's muscle, which normally gives extra lift to the eyelid, causes this classic partial eyelid droop.
3. Increased sweating: Sympathetic loss actually reduces sweating (anhidrosis) on the affected side, not increases it.
4. Abducted eye: Horner's syndrome does not affect the muscles controlling eye position, so there is no abnormal eye deviation.

Since Horner's syndrome results from loss, not excess, of sympathetic tone, ptosis (along with miosis and anhidrosis) is its characteristic feature.

Let's summarize:

• Horner's syndrome is caused by loss of sympathetic supply to the eye and face.
• This produces ptosis, miosis, and anhidrosis, not dilation or increased sweating.

So the characteristic feature is ptosis.