RT Journal Article SR Electronic T1 Midbrain infarction in inherited protein S deficiency: a rare association JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e246073 DO 10.1136/bcr-2021-246073 VO 14 IS 10 A1 Manali Chandra A1 Atanu Chandra A1 Sayantan Chakraborty A1 Joydeep Ghosh YR 2021 UL http://casereports.bmj.com/content/14/10/e246073.abstract AB Inherited thrombophilic disorders are well‐established predisposing factors for venous thromboembolism, but their role in arterial ischaemic stroke is uncertain. The exact mechanism of arterial thrombosis in thrombophilias remains elusive. Herein, we report a case of a 30-year-old woman who was admitted to our facility with sudden-onset right-sided ptosis and ophthalmoplegia. Detailed clinical features, neuroimaging and laboratory evaluation clinched the diagnosis of ischaemic stroke in midbrain due to microvascular obstruction associated with isolated protein S deficiency. She was treated with oral anticoagulant (warfarin) and physiotherapy; without any improvement of her symptoms at 2 months of follow-up. A high index of clinical suspicion is needed in any case of young ischaemic stroke in absence of common cardiac and vascular risk factors, to recognise the presence of inherited thrombophilia.