Protein S Deficiency Resulting in Recurrent Arterial Ischemic Strokes in a Young Female: A Case Report

Introduction: Ischemic stroke in younger adults has been increasing over the years. It is often challenging to identify the underlying etiology and pathogenesis of stroke in the young. Inherited thrombophilias contribute to about 1%–4% of ischemic strokes in the young. Of the inherited thrombophilias, isolated protein S deficiency is an important risk factor for the development of arterial ischemic strokes. It is commonly associated with venous thrombosis but it is rarely associated with arterial ischemic strokes, contributing to 4%–12% of young strokes. Case Description: We report the case of a 38-year-old female who presented with acute onset of weakness in her left upper and lower limbs, whose magnetic resonance imaging brain showed evidence of recurrent arterial ischemic strokes and was detected to have an isolated protein S deficiency. Conclusion: It is very important to identify the underlying etiology in a young patient with stroke. Although protein S deficiency is commonly associated with venous thrombosis, it can be rarely associated with arterial ischemic strokes; hence, thrombophilia workup should always be done in the evaluation of young stroke.