Temporal Arteritis and its Neurological Complications

Definition. Temporal (giant cell) arteritis is a granulomatous large- and medium-vessel vasculitis affecting the extracranial branches of the carotid artery, occurring almost exclusively above the age of 50 (peak 70–80 years). It is the commonest primary systemic vasculitis of old age and is closely associated with polymyalgia rheumatica.

Clinical features. New-onset persistent unilateral temporal headache, scalp tenderness (pain on combing the hair or resting the head on a pillow), jaw claudication — the most specific symptom, and a tender, thickened, nodular or pulseless temporal artery. Constitutional features include fever of unknown origin, weight loss, anorexia and malaise, with pain and morning stiffness of the shoulder and hip girdles if PMR coexists.

Neuro-ophthalmic complications — the core of the answer. Sudden, painless, irreversible monocular visual loss from anterior ischaemic optic neuropathy (commonest), central retinal artery occlusion, or preceding amaurosis fugax; and diplopia from ocular motor palsy. If untreated, the second eye is affected in 25–50% within 1–2 weeks. Other neurological complications: transient ischaemic attack and stroke (characteristically vertebrobasilar), scalp and tongue necrosis, occipital neuropathy, and rarely mononeuritis multiplex, depression and dementia.

Investigations. Raised ESR (often >50 mm/h, classically >75 mm/h) and CRP, with normochromic normocytic anaemia, thrombocytosis and raised alkaline phosphatase. Temporal artery biopsy of a 1–2 cm segment, ideally within 1–2 weeks of starting steroids, shows granulomatous panarteritis with giant cells and fragmentation of the internal elastic lamina — but skip lesions cause false negatives, so a negative biopsy does not exclude the diagnosis. Colour Doppler ultrasound shows the “halo sign”; PET-CT or MR angiography detects large-vessel and aortic involvement.

Treatment — a medical emergency. Start corticosteroids immediately on clinical suspicion; never wait for the biopsy. Without visual symptoms: prednisolone 40–60 mg/day. With visual loss or amaurosis: intravenous methylprednisolone 500–1000 mg/day for 3 days, then oral prednisolone. Add low-dose aspirin and a proton-pump inhibitor. Taper slowly over 12–24 months, guided by symptoms and CRP rather than ESR alone.

Steroid toxicity and steroid-sparing therapy. Older patients are highly vulnerable to osteoporosis and fragility fracture, diabetes, hypertension, cataract, glaucoma, infection, proximal myopathy and delirium. Start calcium, vitamin D and a bisphosphonate from day one, and monitor blood pressure and glucose. Tocilizumab (IL-6 receptor blocker) is the established steroid-sparing agent for relapsing or refractory disease; methotrexate is an alternative. A late complication is thoracic aortic aneurysm, requiring long-term surveillance.

Upadacitinib — the first oral JAK inhibitor approved for giant cell arteritis (European Commission April 2025; FDA 29 April 2025), at 15 mg once daily with a corticosteroid taper. Approval was based on the phase 3 SELECT-GCA trial (n=428), in which 46.4% achieved sustained remission from week 12 to week 52 with a 26-week steroid taper, versus 29.0% on placebo with a 52-week taper (p=0.002); sustained complete remission was 37.1% versus 16.1%. It provides an oral steroid-sparing alternative to tocilizumab — particularly relevant in older patients at high risk of glucocorticoid toxicity.