Seeding of glioblastoma multiforme in the fourth ventricle leading to bilateral internuclear ophthalmoplegia: A case report

Internuclear ophthalmoplegia (INO) is an infrequent disorder impacting conjugate lateral gaze. It is typically observed in neurological conditions like multiple sclerosis and stroke, but it is rarely linked to brain tumors. This report describes a case where INO developed in a patient with a high grade astrocytoma. A 42-year-old man presented with a one-week history of worsening horizontal double vision. Examination revealed impaired adduction and horizontal nystagmus without additional focal neurological deficits or papilledema. MRI imaging of the brain with contrast revealed a large, heterogeneous mass in the left frontal lobe along with ring-enhancing lesions in the fourth ventricle, suggesting tumor progression. The patient had previously undergone a gross total resection of a Grade-4 astrocytoma, followed by radiation therapy and Temozolomide treatment. In response to the new onset of INO, his treatment regimen was adjusted to continue Temozolomide and include steroids. This case underscores the importance of recognizing new ophthalmologic findings as a potential indicator of tumor progression in high-grade astrocytomas, highlighting the need for careful monitoring and treatment modification.