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Neuro Disorders: Temporal ArteritisIntroductionTemporal Arteritis (TA) is also called as GCA (giant cell arteritis) is an inflammatory disease of the temporal artery. The above two terms are not exactly synonymous but many times used with that effect. GCA is the broader term, and Temporal Arteritis is an example for GCA. GCA implies there is inflammation along with infiltration by giant cells in the walls of the arteries, mostly the medium and large sized. So arteries like temporal artery, aorta, ophthalmic artery, occipital artery etc all can get involved with this condition, not necessarily in the same patient. Another closely related condition is PMR (polymyalgia rheumatica) – discussed below. What causes TA?As above it is an inflammatory disease of the arteries. Granulomatous giant inflammatory cell infiltration is seen. It is not a hereditary disease. What triggers the inflammatory reaction is not clear. TA & GCA are considered to be autoimmune disorders, where your immune system instead of protecting, paradoxically attacks your own body. How Does a Patient present?Women are affected more than men. It is extremely uncommon before age 50. Incidence increases after 50 and the highest incidence is around 65 to 70 yeas. The following manifestations are usually seen (on a case to case basis); • New onset Headache • Muscle pain & stiffness especially proximal muscles around the hips & shoulders (PMR – Poly Myalgia Rheumatica) etc PMR is also common in women, and around the same age group as TA. Not all patients with TA have PMR or vice versa but there is some association, means both can co occur in the same patient more than due to just a chance occurrence. Morning stiffness that some what gets better with activities is commonly seen with PMR. The constitutional manifestations like loss of appetite, loss of weight, fatigue, malaise, low grade fever usually occur with both PMR & TA/GCA. By missing PMR in a TA patient you may not harm the patient much but the opposite, i.e. missing TA in PMR patent is a serious issue. DiagnosisThe following investigations are generally performed (some of them like ESR or CRP is a must); • ESR (sed rate) - Elevated Please see that the MRI & ultrasound are not routinely performed or this purpose yet. For high resolution MRI there is some encouraging results but it is not yet routinely available. Ultrasound is routinely available but still there is some controversy regarding its reliability in detecting TA or GCA. The ESR and/or CRP are typically elevated but in some patients they can be negative. Although biopsy is the ultimate test to diagnose this condition but it also cannot provide a cast-iron evidence for TA because the disease affects the artery in a segmental or patchy pattern means biopsy may miss the affected segments. The MRI has the potential to show the surgeon which segment to be taken out for biopsy. Treatment
Once TA is suspected steroid is the drug of choice. Oral prednisone is what is frequently used. Intravenous steroids are reserved for patients with acute visual symptoms. If there are reasons not to use steroids then alternative immunosuppressive agents like azathioprine, methotrexate etc can be used. The treatment is started with a high dose of steroids and then maintained with a small effective dose and after several months gradually the drug can be withdrawn & see whether the disease recurs or not. If recurs the medication has to be restarted. PMR is also treated as above but the steroid dose is typically smaller. Both conditions generally require about 1 to 2 years of maintenance of treatment. A neurologist is frequently involved in the care of patients with Temporal Arteritis and Poly Myalgia Rheumatica.
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