IntroductionIn the United States, cocaine is a commonly used drug of abuse. It is also a recognized contributing factor for both hemorrhagic and ischemic strokes. However, cocaine-induced basilar artery thrombosis has rarely been reported in the literature.Case presentationOur patient was a 51-year-old African American woman with a history of polysubstance abuse who presented to the emergency department for acute behavior changes. Later, during admission, she had a dramatic decrease in motor strength in all extremities and a positive Babinski reflex bilaterally. The results of her toxicology reports were positive for cocaine; in addition, results of magnetic resonance angiography and magnetic resonance imaging were consistent with acute thrombosis and subsequent infarction of the basilar artery. Her mental status improved, but she was only able to communicate via movements of her eyes.ConclusionOur patient developed locked-in syndrome after use of cocaine. Given the prevalence of its use in the United States, cocaine use should be included among the potential causes of locked-in syndrome.