Authors: Marieta Dumitrache, Rodica Lascu, M Burcea, Miruna Cioboat.
Hemianopsia is a visual field defect characterized by the loss of vision in one half of the visual field. It is caused by damage to the optic nerve, optic tract or the visual cortex in the brain.
Common causes of hemianopsia are stroke, brain tumors, multiple sclerosis, migraine. Hemianopsia is Heteronymous and Homonymous. Heteronymous Hemianopsia is Bitemporal and Binasal. Bitemporal Hemianopsia is the pathognomonic for chiasmal lesions in pituitary adenomas (bitemporal hemianopsia and for colors green, red), craniopharyngiomas (asymmetric bitemporal hemianopsia). Binasal heteronymous hemianopsia is rare. Homonymous hemianopsia (with reduced acuity visual) is present in retrochiasmatic lesions: optic chiasmatic gliomas, arachnoiditis opto-chiasmatic, carotid aneurysms, trauma.
Homonymous hemianopsia is right or left. Cause of homonymous hemianopsia is injury located at the occipital lobe 45%, to the optic radiation 12%, optic tract 10%, lateral geniculate nucleus 1,3%.
Homonymous hemianopsia are field defects congruent, or incongruent. Temporal lobe lesions produce superior homonymous hemianopsia “pie in the sky” hemianopsia, frequently incongruent. Parietal lobe lesions produce homonymous hemianopsia inferior “pie on the floor”. Homonymous hemianopsia macular sparing, homonymous scotomas is present in occipital lobe lesions without other neurological deficits symptoms.
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