RÉSUMÉ
This case underscores the importance of treating neurological deficits of an acute stroke presentation despite initial negative diffusion-weighted imaging (DWI), especially in the acute phase when there is high clinical suspicion of stroke. Additionally, it highlights the appropriate use of a WAKE-UP protocol for patients that present with stroke symptoms without a well-defined inception time. A 71-year-old female presented to the emergency department with symptoms of dizziness and double vision upon wake-up. While clinical exam findings revealed left intranuclear ophthalmoplegia (INO) and inability to ambulate due to gait ataxia, magnetic resonance imaging (MRI) was negative for acute stroke. Despite negative DWI MRI, this patient's clinical exam findings of a left INO and gait ataxia were indicative of an ischemic stroke localizing to the medial longitudinal fasciculus (MLF), and the patient received thrombolytics. Repeat MRI about 48 h later revealed an acute infarct in the left midbrain with a DWI lesion in the MLF.