Isolated homonymous hemianopsia due to lateral posterior choroidal artery region infarction: a case report.

An 86-year-old, right-handed, hypertensive man suddenly experienced blurring of vision predominating in the left visual field. Neurological examinations were normal, except for left homonymous hemianopsia. Goldmann visual field testing revealed a left congruent incomplete homonymous hemianopsia with macular splitting. Brain MRI, with a T2-weighted image, demonstrated a lesion of high intensity in the right lateral geniculate body (LGB), as well as the posterior part of the caudate nucleus, posterolateral thalamus, and dorsolateral thalamus. MRA revealed severe stenosis at the second segment of right posterior cerebral artery (PCA). SPECT revealed significantly decreased blood perfusion in the striate cortex. To the best of our knowledge, this is the first case of an isolated, congruent, incomplete, homonymous hemianopsia due to lateral posterior choroidal artery (LPChA) region infarction. The LPChA possibly supplied the LGB through the PCA system. A horizontal, homonymous sectoranopia is typically the hallmark of an LPChA region infarction. However, a homonymous hemianopsia may also occur when the entire LGB has been affected. In the case of homonymous hemianopsia, LGB damage due to LPChA region infarction should be considered, in addition to lesions of the visual pathway, such as the optic tract, optic radiations, and occipital cortex.