Neuro-Ophthalmic Manifestations May Indicate Brainstem Lesions

Brainstem lesions may be identified through their neuro-ophthalmic manifestations, which often present during eye exams, according to research presented at the American Academy of Optometry 2022 annual meeting, held in San Diego, CA, from October 26 to 29, 2022.

Erin Draper, OD, and Kelly Seidler, OD, detailed a case report of a 37-year-old woman with no significant prior medical history presenting with a 5-day history of a left “bulgy” eye and shadowing of her vision. According to the presentation, the afferent visual system was intact, the patient had 20/20 acuity in both eyes, and color plates and visual fields were normal. The pupils were isocoric and reactive with no afferent pupillary defect. 

Extraocular motility testing showed a complete adduction deficit of the right eye as well as a complete abduction deficit of the left eye — signs which are consistent with a left gaze palsy. Examination of the anterior segment was normal with no signs of chemosis or injection, and fundus examination was also normal. 

Further cranial nerve (CN) assessment showed a subtle left peripheral CN VII palsy. Urgent neuroimaging revealed multiple demyelinating lesions, including a lesion in the left low pons affecting the CN VI nucleus and CN VII fascicle. Additional testing ruled out other demyelinating conditions and the patient was diagnosed with multiple sclerosis. 

“Brainstem lesions frequently have multiple neurological and neuro-ophthalmic manifestations,” according to the presenters. “An eye exam already directly tests 4 of the 12 cranial nerves. If damage of one of those 4 nerves is found on eye exam the provider should consider conducting a neurological assessment. This includes testing the remaining cranial nerves to help localize the lesion which can hasten the diagnosis and treatment.”