Protein S Deficiency Revealed by Locked-In Syndrome: A Case Report

Locked-in syndrome (LIS) refers to patients with tetraplegia and lower cranial nerve paralysis but with intact consciousness. The main etiology of this syndrome is pontic ischemic stroke, but it may also be secondary to other less common mechanisms. We report the unusual case of a patient with a Locked-in syndrome following basilar arterial thrombosis related to protein S deficiency highlighting the key role of thrombophilia assessment to help with generally difficult diagnosis.