Congruency in Homonymou Hemianopia Original Reearch Article

Purpoe To evaluate the value of congruency in the localization of brain leion in patient with homonymou hemianopia (HH). Deign Retropective obervational tudy. Method Chart of all patient with HH een over 15 year were reviewed. Only patient with incomplete HH documented on formal viual field teting and neuroimaging were included. HH wa aid to be congruent when the field of both eye were identical in hape, depth, and ize. Patient were divided into two group baed on congruency of HH; demographic, clinical, and radiological characteritic were compared. Reult Five hundred and thirty patient with 548 incomplete HH were included (373 congruent HH and 175 incongruent HH). Demographic variable were imilar in both group. troke caued 75% of congruent HH and 55.8% of incongruent HH; trauma and tumor caued 20.5% of congruent HH and 34.5% of incongruent HH (P < .001). The leion location in congruent HH v incongruent HH included occipital lobe in 47.9% v 21.3%, occipital lobe and optic radiation in 8.3% v 5.6%, optic radiation in 32.4% v 50.6%, optic tract in 7.2% v 16.3%, and other location in 4.2% v 6.3% (P < .0001). Although there wa a trend toward more congruent HH for leion of the poterior viual pathway (P < .001), 50% of optic tract leion and 59% of optic radiation leion produced congruent HH. Concluion Although leion involving the occipital lobe characteritically produce congruent HH, at leat 50% of leion in other location alo produce congruent HH, epecially if thee leion are troke-related. The rule of congruency hould be ued cautiouly and may not apply to optic tract leion.