Oral Contraceptive Pills as a Potential Cause of Wallenberg Syndrome: A Mysterious Case

Wallenberg syndrome, also known as lateral medullary syndrome, is a rare neurological condition caused by an ischemic stroke in the posterior inferior cerebellar artery (PICA) territory of the brainstem. Here, we present a case of Wallenberg syndrome in a relatively healthy 37-year-old woman with no known risk factors besides a history of long-term oral contraceptive pill (OCP) use without prior adverse effects. The patient presented with acute onset headache that worsened in bright light, left-sided lightheadedness, dizziness, blurry vision, and non-bloody, non-bilious emesis. A neurological exam revealed left facial numbness and left upper extremity numbness; however, strength was intact in all extremities. An MRI revealed an acute ischemic infarct in the left PICA distribution, consistent with Wallenberg syndrome. While the initial thought was that the patient's OCP use contributed to this stroke, it has been deduced that the risk of stroke with current formulations of OCPs is insignificant compared to women who do not take any OCPs. This case highlights the importance of reconsidering OCPs as the cause of stroke in young, healthy patients without significant risk factors and considering reclassification as an embolic stroke of undetermined source (ESUS).