PT - JOURNAL ARTICLE AU - Vaidya, Kriti AU - Gor, Shivani AU - Ahmed, Azeem AU - Waheed, Amir TI - Lessons of the month: Giant cell arteritis with Horner's syndrome and vertebral dissection AID - 10.7861/clinmed.2022-0479 DP - 2023 Jan 01 TA - Clinical Medicine PG - 94--96 VI - 23 IP - 1 4099 - http://www.rcpjournals.org/content/23/1/94.short 4100 - http://www.rcpjournals.org/content/23/1/94.full SO - Clin Med2023 Jan 01; 23 AB - We present a case of an 82-year-old woman presenting with left-sided Horner's syndrome and stroke. She also had a 6-week history of intermittent dizziness, reduced appetite, lethargy, muscle stiffness and weight loss. Examination revealed left temporal artery and left posterior auricular artery tenderness. Her ESR showed 62 mm/hr and imaging showed left vertebral artery dissection. Temporal artery biopsy was positive.The case highlights a rare presentation of giant cell arteritis with Horner's syndrome and left vertebral artery dissection. High clinical suspicion is required to prevent delay in diagnosis and treatment.