Intracranial GCA: a comprehensive systematic review

OBJECTIVES: GCA is increasingly recognized to occur in intracranial vessels with unknown clinical ramifications. We identified all reported cases of intracranial GCA (ICGCA) in the literature to describe common presentations, investigations, treatments and outcomes. METHODS: We conducted a systematic review using MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase and PubMed databases to identify studies that reported cases of ICGCA. The study was registered on a systematic review database (PROSPERO 42023412373). We defined intracranial involvement as any vessel cranial to the dura mater that was confirmed by either histopathology or imaging. Data were summarized using descriptive statistics. RESULTS: Of 1554 studies identified, 102 studies underwent full-text review. These studies included 340 patients with ICGCA. The median age was 73.7 (interquartile range [IQR] 71.9-77.3) and 46.9% patients were female. Presentations of ICGCA included stroke in 240 (70.6%) patients and isolated intracranial imaging or histologic changes in 67 (19.7%) patients. The most common vessels involved were 180 (52.9%) vertebrobasilar, 166 (48.8%) internal carotid and 49 (14.4%) ophthalmic arteries. Treatment was reported in 214 individuals. Glucocorticoids were administered to 210 (98.1%); tocilizumab, cyclophosphamide and methotrexate were the most common adjunctive medications. Of the 181 patients with reported follow-up outcomes, relapse occurred in 40 (22.1%) patients and 59 (32.6%) individuals died. CONCLUSION: Our findings suggest that ICGCA is not a rare entity and may represent a more severe manifestation of GCA. Optimal therapy for ICGCA is unknown. Structured prospective evaluation is needed to better understand this manifestation of GCA.