# A Case of Horner’s Syndrome Aiding the Diagnosis of Internal Carotid Artery Dissection (ICAD): A Life-Saving Twist of Fate

## TL;DR

A patient's Horner's syndrome led to the diagnosis of a life-threatening carotid artery dissection, highlighting the importance of early detection.

## Contribution

This case demonstrates how Horner's syndrome can serve as a critical diagnostic clue for internal carotid artery dissection.

## Key findings

- Horner's syndrome with pain was a key indicator of internal carotid artery dissection in this patient.
- MRI confirmed the dissection and guided timely treatment with antiplatelets and anticoagulants.
- Early diagnosis and intervention were crucial in preventing severe complications.

## Abstract

A 59-year-old male patient came to the outpatient department with complaints of left-sided hemicranial headache with drooping of the left upper eyelid (UL) for three days associated with difficulty in swallowing and deviation of the tongue. The patient had a history of vigorous coughing for the past 15 days for which he did not take any medications. He was thoroughly evaluated in the outpatient department and diagnosed with Horner's syndrome. Acute Horner's syndrome with pain is nearly a hallmark of carotid dissection, and MRI of the brain and orbit was thus advised. On MRI, a hyperdense area was noted around the left internal carotid artery for which he was advised magnetic resonance angiography, which revealed internal carotid artery dissection (ICAD) of the left side. The patient was diagnosed with left-sided Horner's syndrome following left ICAD with involvement of the left hypoglossal nerve. He was started on antiplatelets and anticoagulants and closely followed up. Early diagnosis and prompt treatment were lifesaving for this patient.