Case of Internuclear Ophthalmoplegia Caused by an Acute Lacunar Infarct in the Right Dorsal Pons Following Percutaneous Cardiac Intervention — 58p — Angela Roberts¹, Michael Roberts², Dr. Nessim Amin³

¹MS 4, USD Sanford School of Medicine, Sioux Falls, SD.
²MS 3, USD Sanford School of Medicine, Sioux Falls, SD.
³Clinical Associate Professor, USD Sanford School of Medicine, Sioux Falls, SD.

Internuclear ophthalmoplegia or INO is a conjugate gaze abnormality, often caused by a medial longitudinal fasciculus (MLF) lesion, that presents with clinical features like impaired adduction of the ipsilateral eye and nystagmus of the contralateral eye on abduction. MLF lesions are frequently caused by brainstem infarcts and multiple sclerosis but less commonly by acute lacunar infarcts in the setting of percutaneous cardiac intervention. We present a case of an MLF lesion in a 58-year-old male who showed symptoms of dizziness and double vision after cardiac catheterization. He had nausea and vomiting, which improved with closing his right eye. He was unable to adduct his right eye and had nystagmus of his left eye on exam. Initial MRI was within normal limits, but repeat MRI of the brain limited with BS cuts with contrast revealed punctate focus on restricted diffusion in the right dorsal pons compatible with a small acute infarct. The patient was diagnosed with acute right medial rectus palsy with binocular diplopia or right INO. The patient was referred to ophthalmology, who recommended monitoring symptoms, which were gradually improving with an eye patch, indicating that he may slowly improve on his own. INO is often due to lesions of the MLF, which carries CN III, IV, VI and the PPRF. In this patient, improvement to his vision, dizziness, and nausea were noted after wearing a right eye patch, possibly due to less activation of the right MLF. Proper bedside neurological exams and imaging modalities are important as it was after repeat MRI of the brain limited with BS cuts with contrast that a small acute infarct punctate focus was seen in the right dorsal pons. Clinical presentations include dizziness and nausea that are ameliorated by closing one’s eyes and internuclear ophthalmoplegia.

University of South Dakota
Dr. Nessim Amin