Homonymous Hemianopsia as the Presenting Sign of Tumefactive Multiple Sclerosis

Tumefactive demyelination is a rare form of multiple sclerosis (MS) characterized by demyelinating lesions that present similarly to a brain mass. Misdiagnosis is a common occurrence and often requires further testing. The development of relapsing-remitting multiple sclerosis (RRMS) often coincides with tumefactive MS - commonly affecting young adults and involves exacerbations with intermittent periods of recovery. Internuclear ophthalmoplegia or optic neuritis are common neuro-ophthalmic causes of visual disturbances in MS. Though homonymous hemianopsia has been reported in RRMS as an infrequent disruption of the visual pathway, it remains an unusual presenting sign of tumefactive MS in a previously healthy patient. The authors aim to raise awareness that homonymous hemianopic defects may be a the initial sign of tumefactive MS.