ABSTRACT NUMBER: ESOC2026A173 ACUTE ISCHEMIC STROKE IN PREGNANCY DUE TO HERPES SIMPLEX VIRUS TYPE 2-ASSOCIATED CEREBRAL VASCULITIS: DIAGNOSTIC AND THERAPEUTIC CHALLENGE

Abstract Background and aims A 32-year-old woman, 7 weeks pregnant, presented with symptoms suggestive of right middle cerebral artery involvement upon awakening. The initial NIHSS score was 11. These case highlights the diagnostic and therapeutic challenges of acute ischemic stroke in early pregnancy, particularly when treatment decisions must be weighed against maternal and fetal considerations. Methods Urgent cranial MRI was performed, confirming acute ischemic lesions and a proximal right middle cerebral artery occlusion with >50% parenchymal penumbra. Intravenous reperfusion therapy was not possible due to time constraints; therefore, endovascular therapy was pursued. Selective catheterization of the right common carotid artery revealed no occlusion but a “string-of-beads” appearance suggestive of vasculitis. During hospitalization, extensive workup included cardiac monitoring, structural heart evaluation, serum autoimmunity, coagulation studies, and neurosonology; all were unremarkable. Lumbar puncture PCR confirmed herpes simplex virus type 2 infection, prompting initiation of antiviral therapy. Results The patient showed favourable neurological improvement under acyclovir and rehabilitative care, with NIHSS 4 at discharge. Neuroimaging and clinical follow-up did not reveal other causative factors for the stroke. Regarding pregnancy, four weeks post-event, a delayed miscarriage occurred but no iatrogenic cause was confirmed. Conclusions This case illustrates the complex interplay between acute ischemic stroke management, rare vascular findings, and infectious ethiology in early pregnancy. HSV-2 vasculitis should be considered in stroke patients with atypical vascular imaging, and endovascular therapy can be performed safely in select pregnant patients when indicated. Early recognition and targeted antiviral therapy contributed to favourable neurological outcomes despite the adverse obstetric outcome. Conflict of interest Beatriz Villarrubia: nothing to disclose