## **Core Concept**
Cervical sympathetic lesions, also known as Horner's syndrome when complete, result from disruption of the sympathetic pathway that supplies the head and neck. This pathway involves the hypothalamus, brainstem, and sympathetic nerves that run through the neck. The symptoms of cervical sympathetic lesions include ptosis, miosis, and anhidrosis.

## **Why the Correct Answer is Right**
The correct answer, which is not a feature of cervical sympathetic lesion, needs to be identified based on the understanding of Horner's syndrome and sympathetic nervous system disruption. Typically, Horner's syndrome presents with ptosis (drooping eyelid), miosis (pupil constriction), and anhidrosis (lack of sweating) on the affected side of the face.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Ptosis is a feature of cervical sympathetic lesion due to the interruption of sympathetic nerves supplying the superior tarsal muscle, which assists in eyelid elevation.
- **Option B:** Miosis occurs due to the unopposed action of the parasympathetic nerves on the pupil, leading to constriction.
- **Option C:** Anhidrosis (reduced sweating) on the face is a classic symptom due to the interruption of sympathetic nerves that stimulate sweat glands.

## **Why Option D is Correct and Others are Incorrect in the Context of the Question**
- **Option D:** Increased sweating (hyperhidrosis) is not a feature of cervical sympathetic lesions; instead, these lesions lead to decreased sweating (anhidrosis) on the affected side of the face.

## **Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that Horner's syndrome can result from lesions at various levels of the sympathetic pathway, including the brainstem (e.g., lateral medullary syndrome), the sympathetic chain in the neck, or the stellate ganglion. Identifying the level of the lesion can help in diagnosing the underlying cause.

## **Correct Answer: D. Increased sweating**