IRCCS Stella Maris, 56128 Pisa, Italy.
Department of Neuroscience, University of Florence, 50121 Firenze, Italy.
Int J Mol Sci. 2022 Jan 19;23(3):1055. doi: 10.3390/ijms23031055.
Impairment of the geniculostriate pathway results in scotomas in the corresponding part of the visual field. Here, we present a case of patient IB with left eye microphthalmia and with lesions in most of the left geniculostriate pathway, including the Lateral Geniculate Nucleus (LGN). Despite the severe lesions, the patient has a very narrow scotoma in the peripheral part of the lower-right-hemifield only (beyond 15° of eccentricity) and complete visual field representation in the primary visual cortex. Population receptive field mapping (pRF) of the patient's visual field reveals orderly eccentricity maps together with contralateral activation in both hemispheres. With diffusion tractography, we revealed connections between superior colliculus (SC) and cortical structures in the hemisphere affected by the lesions, which could mediate the retinotopic reorganization at the cortical level. Our results indicate an astonishing case for the flexibility of the developing retinotopic maps where the contralateral thalamus receives fibers from both the nasal and temporal retinae.
视放射通路的损伤会导致相应视野部分出现盲点。在这里，我们介绍了一个左眼小眼球和大部分左侧视放射通路（包括外侧膝状体核）损伤的患者 IB 的病例。尽管病变严重，但患者的右下视野周边部分只有非常狭窄的盲点（超过 15°的偏心度），并且初级视皮层的视野代表完整。患者视野的群体感受野映射（pRF）显示有序的偏心度图谱，同时两个半球均出现对侧激活。通过弥散张量成像，我们揭示了受病变影响的半球中上丘和皮质结构之间的连接，这可能介导了皮质水平的视敏度重组。我们的结果表明，发育中的视敏度图谱具有惊人的灵活性，即对侧丘脑接收来自鼻侧和颞侧视网膜的纤维。
