Imagine a neighborhood devastated by a powerful storm. The once lush green trees are now uprooted and twisted, and the roads are riddled with debris. In a similar way, researchers have discovered that patients who have experienced a thalamic stroke—a type of brain injury—may exhibit alterations in both the optic tract and retinal structure. Using advanced imaging techniques like magnetic resonance imaging (MRI) and optical coherence tomography (OCT), scientists measured the shrinkage of the optic tract and thickness of various layers in the retina. The findings revealed that patients with thalamic stroke had abnormal shrinkage in their optic tracts compared to healthy individuals. Moreover, this shrinkage was more pronounced in patients whose strokes occurred over six months ago. Interestingly, the extent of optic tract atrophy was associated with thinning of a specific retinal layer called peripapillary retinal nerve fiber layer (pRNFL). Additionally, both the optic tract shrinkage and pRNFL thinning were correlated with changes in visual acuity. These exciting findings shed light on the complex relationship between thalamic stroke, optic tract alterations, retinal structure changes, and visual impairments. Further research in this area could contribute to interventions or therapies that help restore vision in individuals affected by thalamic stroke.

ObjectivesTo investigate the association between degeneration of retinal structure and shrinkage of the optic tract in patients after thalamic stroke.Materials and methodsPatients with unilateral thalamic stroke were included. Structural magnetic resonance imaging (MRI) and optical coherence tomography (OCT) were performed to obtain parameters of optic tract shrinkage (lateral index) and retina structural thickness (retinal nerve fiber layer, RNFL; peripapillary retinal nerve fiber layer, pRNFL; ganglion cell-inner plexiform layer, GCIP), respectively. Visual acuity (VA) examination under illumination was conducted using Snellen charts and then converted to the logarithm of the minimum angle of resolution (LogMAR). We investigated the association between LI and OCT parameters and their relationships with VA.ResultsA total of 33 patients and 23 age-sex matched stroke-free healthy controls were enrolled. Patients with thalamic stroke showed altered LI compared with control participants (P = 0.011) and a significantly increased value of LI in the subgroup of disease duration more than 6 months (P = 0.004). In these patients, LI were significantly associated with pRNFL thickness (β = 0.349, 95% confidence interval [CI]: 0.134–0.564, P = 0.002) after adjusting for confounders (age, sex, hypertension, diabetes, dyslipidemia, and lesion volume). LI and pRNFL were both significantly associated with VA in all patients (LI: β = −0.275, 95% CI: −0.539 to −0.011, P = 0.041; pRNFL: β = −0.023, 95% CI: −0.046 to −0.001, P = 0.040) and in subgroup of disease duration more than 6 months (LI: β = −0.290, 95% CI: −0.469 to −0.111, P = 0.002; pRNFL: β = −0.041, 95% CI: −0.065 to −0.017, P = 0.003).ConclusionShrinkage of the optic tract can be detected in patients with thalamic stroke, especially after 6 months of stroke onset. In these patients, the extent of optic tract atrophy is associated with pRNFL thickness, and they are both related to visual acuity changes.

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