Bander Dallol, Hala AlsafadiA 60-year-old man presented to the accident and emergency department with a 2-day history of constant left-sided supraorbital headache, associated with ipsilateral facial numbness and blurred vision. On examination he had left ptosis and miosis (Figure 1) with no other focal neurology identified. His blood pressure was 195/120 mmHg and his pulse was regular, at 75 beats per minute. Horners syndrome was diagnosed and a CT scan of his neck revealed a common carotid artery dissection (Figure 2). This was treated conservatively. The patient made a good recovery and was discharged home. Figure 1. Photograph showing miosis with ptosis on the left side Figure 2. CT scan with contrast demonstrating the dissected origin of common carotid artery (arrow) Internal carotid artery dissection is under-recognised as a cause of Horners syndrome and can be missed. It can be caused by minor or major trauma, or can be spontaneous. Painful Horners syndrome should alert clinician to the possibility of a silent carotid dissection. The treatment advocated for dissection is anticoagulation to prevent carotid thrombosis and embolism.

Bander Dallol, Hala AlsafadiA 60-year-old man presented to the accident and emergency department with a 2-day history of constant left-sided supraorbital headache, associated with ipsilateral facial numbness and blurred vision. On examination he had left ptosis and miosis (Figure 1) with no other focal neurology identified. His blood pressure was 195/120 mmHg and his pulse was regular, at 75 beats per minute. Horners syndrome was diagnosed and a CT scan of his neck revealed a common carotid artery dissection (Figure 2). This was treated conservatively. The patient made a good recovery and was discharged home. Figure 1. Photograph showing miosis with ptosis on the left side Figure 2. CT scan with contrast demonstrating the dissected origin of common carotid artery (arrow) Internal carotid artery dissection is under-recognised as a cause of Horners syndrome and can be missed. It can be caused by minor or major trauma, or can be spontaneous. Painful Horners syndrome should alert clinician to the possibility of a silent carotid dissection. The treatment advocated for dissection is anticoagulation to prevent carotid thrombosis and embolism.