A Case of Optic Neuritis Involving Optic Chiasm

ABSTRACT

PURPOSE: To report a case of optic neuritis with incongruous homonymous hemianopia involving optic chiasm. METHODS: A twenty five year old female patient complaining of decreased visual acuity in left eye for 4 days was referred from department of neurology. Best corrected visual acuity was 1.0 in the right eye and counting fingers at 20 cm in the left eye. Left afferent pupillary defect was detected. The conventional magnetic resonance image was normal, however on FLAIR image high signal intensity lesion involving left anterior portion of optic nerve, optic chiasm and both optic tract was noted. However the lesion was not easily detected on T2-weighted image. On enhanced MRI image, the lesion was partially enhanced. Visual field showed incongruous homonymous right hemianopia. VEP showed no evoked potentials in left eye stimulation by checkboard pattern and normal response in right eye stimulation. The patient had normal CSF studies and had been treated with high dose intravenous steroid. After 19 days, visual acuity and magnetic resonance image was markedly improved. RESULTS: We experienced a case of optic neuritis with incongruous homonymous hemianopia involving optic chiasm and report this case with literature review as we believe that our case is the first case in our country.