A 67-year-old woman presented to her GP with sudden onset of visual disturbance in her right eye accompanied by a throbbing headache on the right side of her head. She described the visual disturbance as a moving silhouette descending from above leading to complete visual loss, which lasted for about a minute and then resolved. She also complained of pain in her jaw while chewing food and when combing her hair. This had occurred several times in the past week. The patient had a medical history of hypertension and polymyalgia rheumatica and was taking bendroflumethiazide 2.5 mg/day.
On examination, the patient was alert and oriented. Her blood pressure was 140/75 mmHg, and her pulse was 76/min and regular. She had an ejection systolic murmur radiating into the neck and no carotid bruits on cardiovascular examination. Fundoscopy examination revealed bilateral silver wiring and AV nipping. The right temporal/jaw area appeared tender and pulsatile. Peripheral nervous system examination was normal.
Investigations showed that the patient had a low haemoglobin level, high platelet count, and high ESR (Westergren). Carotid Dopplers revealed that the left internal carotid artery had 100% stenosis, while the right internal carotid artery had less than 50% stenosis. The patient’s cholesterol level was high, and her other blood test results were within normal limits.
What is the likely diagnosis for this patient?