A Unique Case of Internuclear Ophthalmoplegia and Artery of Percheron Infarct.

This case report discusses a unique presentation of an artery of Percheron (AOP) infarct resulting in rapidly resolving internuclear ophthalmoplegia (INO) without classical signs. This is the case of a 70-year-old male patient who presented to a community Emergency Department following acute code stroke activation. Physical exam and imaging studies including non-contrast CT, CT angiography, CT perfusion, and MRI were performed. A review of the literature was also conducted. MRI confirmed acute bilateral thalamic ischemic changes consistent with AOP infarcts. Symptoms of acute blurred vision, slurred speech, right hemi-face and tongue numbness, and signs of anisocoria, left INO, mild left skew deviation, and impaired convergence on the left resolved within 48 hours without intervention. The patient was discharged as neurologically normal and follow-up investigations did not identify a cause for the stroke. The literature suggests varying presentations of AOP infarcts, with INO being rare. This case deviates from classical AOP presentations, emphasizing the importance of considering AOP infarcts early in differential diagnoses, particularly with unusual neuro-ophthalmological findings. Imaging modalities such as MRI with DWI prove crucial for early diagnosis, although AOP occlusions remain challenging to detect due to the small vessel size. Our case contributes to expanding knowledge of AOP infarct presentations and underscores the need for vigilance in recognizing atypical manifestations for timely diagnosis/management.