Splenial Callosal Disconnection in Right Hemianopic Patients Induces Right Visual-Spatial Neglect

Abstract

Posterior cerebral artery (PCA) territory infarction involving occipital cortical damage can give rise to contralateral homonymous hemianopia. Here, we report two rare cases of patients with lesions in the left hemisphere PCA territory who developed right visuo-spatial neglect. One patient suffered right hemianopia and right visuo-spatial neglect after a stroke that damaged the left primary visual cortex and the callosal splenial fibers. The other unique case is of a patient who had a brain tumor in the posterior cerebral region in the left hemisphere and initially exhibited only right hemianopia that developed into right visuo-spatial neglect after tumor resection that included the splenial fibers. These cases indicate that, as in cases with damage in the right PCA territory, lesions in the left PCA yield visuo-spatial neglect when the damage produces contralateral hemianopia and concomitant disconnection of the splenium of the corpus callosum, which interferes with the arrival of visual inputs from the intact right to the lesioned left hemisphere. These results also emphasize the necessity of sparing the splenial fibers in surgical interventions in patients who exhibit hemianopia.

Immersive virtual reality gameplay detects visuospatial atypicality, including unilateral spatial neglect, following brain injury: a pilot study

“…Patients showed significantly greater cognitive (median, 5.6; IQR, 1.8) than motoric independence (median, 3.4; IQR, 3.3; W = 8.0, P < 0.001). Three patients (23.1%; patients 17,19,21) showed left-side neglect on ≥ 1 pen-and-paper test and the neuropsychologist agreed the result was due to neglect rather than other causes (identified in Table 2 as 'neglect present'). One patient (patient 9) showed performance consistent with right-side neglect on the SLCT, but the neuropsychologist attributed this to causes other than neglect.…”

“…Although attention can recover during rehabilitation [10], current treatments produce uncertain evidence of efficacy [11,12]. Neglect occurs most commonly following right-hemisphere stroke [13], but can also follow left-hemisphere stroke [14], traumatic brain injury (TBI) [15], and other causes of acquired brain injury (ABI) [16,17]. Prevalence estimates of neglect vary widely (e.g., 24-68%) [18,19], reflecting a variety of factors, including limitations of standard assessments [20].…”

Brain disconnections refine the relationship between brain structure and function

“…Second, are articles that indirectly measure disconnections in the brain by inferring disruptions based on imaging from large groups of healthy individuals with high-quality imaging or brain atlases (Thiebaut de Schotten et al 2015;Boes et al 2015). Articles in this category include: (Souter et al 2022;Conrad et al 2022;Sperber et al 2022;Hajhajate et al 2022;Tomaiuolo et al 2022;Dulyan et al 2022;Yeager et al 2022). As with any new field, there are many opportunities to refine and improve the methods of disconnectome mapping.…”