Acute, painful Horner syndrome can be the presenting manifestation of an extracranial internal carotid artery (ICA) dissection, which is important to identify because of the high risk of stroke. Internal Carotid artery dissection (ICAD) has an incidence of 2.6-3.0 per 100,000, whereas spontaneous ICAD accounts for only 2% of all ischemic strokes. ICAD presents as Horner’s syndrome in about 36-58% and this is a case of Internal Carotid Artery dissection presenting as Horner’s syndrome. ICAD involves tear in the inner lining of the carotid artery, leading to the formation of a blood clot. This can reduce blood flow to the brain, leading to ischemic stroke, but it can also cause dissection of the sympathetic nerves that run alongside the carotid artery, resulting in Horner’s syndrome. Therefore, the coexistence of these two conditions in the same patient presents a fascinating clinical scenario. Although Carotid endartectomy is the main modality of treatment, anticoagulants and antiplatelet can be given.

Keywords: Internal Carotid artery dissection, Partial Horner’s syndrome, Mild Ptosis.

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Dr Nivethini.N

Post Graduate Resident, Department of Internal Medicine, Sri Manakula Vinayagar Medical College and Hospital – Puducherry