TY  - JOUR
AU  - Bisten, Justus
AU  - Grün, Johannes
AU  - Hoppe, Christian
AU  - Bauer, Tobias
AU  - Held, Nina Rebecca
AU  - Rose, Renata
AU  - Althausen, Anita
AU  - Witt, Juri-Alexander
AU  - Borger, Valeri
AU  - Schneider, Matthias
AU  - Vatter, Hartmut
AU  - Helmstaedter, Christoph
AU  - Radbruch, Alexander
AU  - Surges, Rainer
AU  - Schultz, Thomas
AU  - Rüber, Theodor
TI  - Structural White Matter Correlates of the Crowding Effect: Insights From a Tractography Study of the Arcuate Fasciculus Post-Hemispherotomy.
JO  - Human brain mapping
VL  - 46
IS  - 9
SN  - 1065-9471
CY  - New York, NY
PB  - Wiley-Liss
M1  - DZNE-2025-00733
SP  - e70258
PY  - 2025
AB  - The neuropsychological crowding effect denotes the reallocation of cognitive functions within the contralesional hemisphere following unilateral brain damage, prioritizing language at the expense of nonverbal abilities. This study investigates structural white matter correlates of crowding in the arcuate fasciculus (AF), a key language tract, using hemispherotomy as a unique setting to explore structural reorganization supporting language preservation. We explore two main hypotheses. First, the contralesional right AF undergoes white matter reorganization correlated with preserved language function at the expense of nonverbal abilities following left-hemispheric damage. Second, this reorganization varies with epilepsy etiology, influencing different stages of developmental language lateralization. This retrospective study included individuals post-hemispherotomy and healthy controls. Inclusion criteria were; (1) being a native German speaker, (2) having no MRI contraindication, (3) the ability to undergo approximately 2 h of MRI scans, and (4) the ability to participate in neuropsychological assessments over two consecutive days. Neuroimaging included T1-, T2-, and diffusion-weighted imaging, alongside postoperative neuropsychological assessments, where it was taken as evidence for crowding if verbal IQ exceeded performance IQ by at least 10 points. The AF was reconstructed using advanced tractography, and CoBundleMAP was used to compare morphologically corresponding AF subsections. Statistical significance was set at  p < 0.05  , with correction for multiple comparisons applied across contiguous tract sections using Threshold-Free Cluster Enhancement. The final cohort comprised 22 individuals post-hemispherotomy (median age:  20.4  years, range:  12.3−43.9  ; 55
KW  - Humans
KW  - Female
KW  - White Matter: diagnostic imaging
KW  - White Matter: pathology
KW  - Male
KW  - Diffusion Tensor Imaging
KW  - Adult
KW  - Retrospective Studies
KW  - Hemispherectomy
KW  - Young Adult
KW  - Functional Laterality: physiology
KW  - Middle Aged
KW  - Adolescent
KW  - Language
KW  - Neural Pathways: diagnostic imaging
LB  - PUB:(DE-HGF)16
C6  - pmid:40536189
C2  - pmc:PMC12177811
DO  - DOI:10.1002/hbm.70258
UR  - https://pub.dzne.de/record/279356
ER  -