A critically ill postpartum woman with fatal hyperammonemic encephalopathy by intracranial venous sinus thrombosis

Key Clinical Message: This case highlights the importance of considering metabolic disorders, such as ornithine transcarbamylase deficiency (OTCD), in postpartum women presenting with altered consciousness, seizures, and neurological deficits. In this 29-year-old patient, the initial diagnosis of transverse sinus thrombosis was complicated by the identification of hyperammonemic encephalopathy, a rare but critical condition. Elevated blood ammonia levels, in conjunction with neuroimaging findings, prompted the diagnosis of OTCD, confirmed by genetic testing. Despite appropriate treatment, the patient experienced irreversible neurological damage, underscoring the need for early recognition and intervention in such cases.