Headache-related characteristics of biopsy-confirmed giant cell arteritis and the relationship of transmural inflammation with artery tenderness and chordal thickening

Giant cell arteritis (GCA) is characterised by headache, but few studies have examined detailed characteristics in pathologically confirmed cases. We aimed to investigate the characteristics of GCA, particularly headache, and their correlation with pathologic findings. We retrospectively analysed 26 patients (median age: 77.5 years, male: 38.4%) with GCA who underwent superficial temporal artery (STA) biopsy at the Japanese Red Cross Shizuoka Hospital between May 2001 and February 2022. All patients fulfilled the American College of Rheumatology and European League Against Rheumatism diagnostic criteria for GCA. We focused on the relationship between clinical features, especially headache, and pathologic findings. Twenty-four patients had unilateral, non-pulsating, intermittent headaches. Transmural inflammation (TMI), a characteristic pathology of GCA, was present in 14 patients. Bivariate analysis revealed significant associations between TMI and STA tenderness (odds ratio [OR]=11, 95% confidence interval [CI] 1.14 to 106.43, p=0.046) and between TMI and STA chordal thickening (OR=0.19, 95% CI 0.068 to 0.52, p=0.021). Headache in GCA patients was often unilateral, non-pulsatile, and intermittent. This study highlights the significant association of TMI with STA tenderness and ligamentous thickening, which has not been reported previously. Abnormal STA findings were significantly associated with pathologic changes in GCA, emphasising their importance in suspecting GCA.