Giant Cell Arteritis With Central Nervous System Vasculitis Presenting As Binocular Diplopia and Ptosis due to Third Cranial Nerve Palsy.

We report the case of a woman in her 60s with no notable comorbidities presented with a four-week history of bilateral temporal headache, scalp tenderness, jaw claudication, and sporadic fever. She also reported binocular diplopia for the previous 24 hours. Examination revealed tender superficial temporal arteries (TA) and right-sided third cranial nerve palsy with ptosis. Laboratory tests showed elevated inflammation markers. Cranial and cervical computed tomography (CT) and CT angiography (CTA) were unremarkable. She was treated with a single dose of intravenous methylprednisolone, followed by oral prednisolone. Subsequent TA duplex ultrasound demonstrated artery wall thickness, and TA biopsy confirmed chronic inflammation with disruption of the internal elastic lamina, both consistent with giant cell arteritis. Cranial magnetic resonance imaging (MRI) revealed scattered punctate areas on T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences, consistent with small-vessel vasculitis. Under corticosteroid treatment, the patient achieved full clinical remission at the four-month follow-up. This case illustrates an uncommon neurological presentation of giant cell arteritis with oculomotor nerve involvement, associated with findings suggestive of central nervous system vasculitis, and highlights the importance of early recognition and prompt corticosteroid treatment to prevent irreversible complications.