Giant cell arteritis.
Giant cell arteritis (GCA or temporal arteritis or cranial arteritis) or Horton’s disease, is an inflammatory disease of the blood vessels that most often involves the large, middle arteries of the head. The external carotid artery branches are more frequently involved. It is a form of vasculitis.
The name (giant cell arteritis) reflects the type of inflammatory cells involved, apparently seen on biopsy.
Because of the frequent involvement of the temporal artery, the terms “giant cell arteritis” and “temporal arteritis” are sometimes used interchangeably. It can also involve other large vessels (e.g., aorta “giant cell aortitis”). Giant cell arteritis of the temporal artery is called temporal arteritis and is also referred to as “cranial arteritis” and “Horton’s disease”.
Signs.
It is more common in women, with a 2:1 ratio of women to men, and more common in whites than blacks. The average age of onset is 55 years, and it is rare in people younger than 55 years.
Patients present with.
Murmur; fever; headache; scalp tenderness and sensitivity; jaw lameness (jaw pain when chewing); tongue lameness (tongue pain when chewing) and necrosis; decreased visual acuity (blurred vision); acute visual loss (sudden blindness); diplopia (double vision); acute tinnitus (ringing in the ears); rheumatic polymyalgia (in 50%) inflammation can affect the blood supply to the eyes and blurred vision, or sudden blindness may occur. In 76% of cases involving the eye, the ophthalmic artery is often involved, causing arteritis anterior ischemic optic neuropathy, which may occur very suddenly with loss of vision in both eyes, making this disease an internal medical emergency.
Related conditionsThe disease can coexist (1/4 cases) with rheumatic polymyalgia, which is characterized by sudden onset of muscle (pelvic, shoulder) pain and stiffness, seen in the elderly. Giant cell arteritis and rheumatic polymyalgia are so closely linked that they are often considered to be different manifestations of the same disease process. Other diseases associated with temporal arteritis are systemic lupus erythematosus, rheumatoid arthritis, and severe infections.
Diagnostic physical examination.
Palpation of the head shows significant temporal artery pulsation either with or without.
1. The temporal region may be tender.
2. A decreased pulse (arterial pulsation) may be noted throughout the body.
3, Evidence of ischemia may be noted on funduscopic examination.
Laboratory tests.
Liver function, liver function tests, ALP alkaline phosphatase is particularly paradoxically elevated.
1, Erythrocyte sedimentation rate, a marker of inflammation, > 60 mm/hour (normal 1-40 mm/hour) .
2. C-reactive protein, another marker of inflammation, is also usually elevated.
3, Platelets may also be elevated Biopsy The gold standard for the diagnosis of temporal arteritis is biopsy, which involves removing a small portion of the vessel and microscopically examining it to look for giant cells infiltrating the tissue. Because the affected vessels are in a patchy form, it is possible that there are unaffected areas on the vessels that the biopsy may have taken. 1.5-3 cm long unilateral biopsies have a sensitivity of 85-90%. (minimum 1 cm). Therefore, a negative result does not absolutely exclude the diagnosis. Therefore, biopsy is currently considered only as a confirmation of the clinical diagnosis, or one of the diagnostic criteria.
Imaging studies temporal artery imaging with ultrasound produce the halo sign. Contrast-enhanced brain MRI and CT, which are generally negative. Recent studies have shown that 3T MRI using ultra-high resolution imaging and contrast injection is able to diagnose this disorder non-invasively, with high specificity and sensitivity.
Treatment with corticosteroids, usually high dose prednisone (40*60 mg once daily). Once the diagnosis is suspected, administration must be initiated, (even before biopsy confirms the diagnosis), to prevent irreversible blindness secondary to ophthalmic artery obstruction. Steroids do not prevent the diagnosis from being made later by biopsy, although certain histological changes can be observed near the end of the first week of treatment; it will be difficult to establish the diagnosis after several months. The dose of prednisone is reduced after 2-4 weeks and then tapered after 9-12 months. Dose reductions may take two or more years. Oral steroids are at least as effective as intravenous steroids, except for the treatment of acute vision loss, when intravenous steroids provide significant benefits over oral dosing.