ABSTRACT NUMBER: ESOC2026A1717 CONCOMITANT INTERNAL CAROTID ARTERY OCCLUSION AND CEREBRAL VENOUS THROMBOSIS IN A YOUNG ADULT WITH MILD HYPERHOMOCYSTEINEMIA: A CASE REPORT

Abstract Background and aims Concomitant internal carotid artery occlusion and cerebral venous thrombosis in yuong patient without cardiovaskular risk factors is uncommon and can present a diagnostic challenge . This case report highlights the diagnostic workup of a young male presenting with these two thrombotic events.The pathogenic role of hyperhomocisteinemia remains controversial, however hyperhomocysteinemia may contribute to a prothrombotic state. Methods Case Presentation:A 39-year-old male with no significant medical or family history, no cardiovascular risk factors, presented to our ED with rightsided hemiparesis that had started 10 days prior. He also reported a sudden headache on the same day but had delayed seeking medical care.CT scan of the brain showed hypodensity in the parietal lobe, suggestive of an ischemic stroke.He was admitted for further evaluation. Brain MRI, neck-head angio-MRI revealed focal atrophic malacic changes in the left parietal region consistent with ICA occlusion, along with occlusion of the left transverse venous sinus, but no evidence of acute ischemia. Further investigations were conducted to identify potential underlying causes of prothrombotic state, including thrombophilia, vasculitis, infections, tumoral markers for paraneoplastic coagulopathy. Comprehensive tests yielded normal results.The only abnormal finding was hyperhomocysteinemia, serum homocysteine level of 22.9μmol/L ( 3.4-15). Conclusions This case emphasizes the need for a thorough investigation of young patients presenting with unusual thrombotic events, even in the absence of conventional risk factors. Moderate hyperhomocysteinemia may play a role in the development of both ICA occlusion and CVT, although the exact mechanism remains uncertain. Clinicians should consider hyperhomocysteinemia as a contributing factor when other causes are excluded. Conflict of interest No