Disrupted Frontal Connections in Band Heterotopia Mapped by Diffusion Tensor Tractography

Abstract

Purpose: To examine white matter abnormalities in band heterotopia (BHT) using diffusion tensor imaging (DTI). Patients and Methods: A 17-year-old female with BHT was scanned and white matter fiber tracts were mapped using three-dimensional DTI-based tractography. Results: Fragmented fibers were found in the patient´s prefrontal lobe and association cortex, most of which were not comparable to healthy controls. Furthermore, fibers in the corpus callosum were sparse, and the majority of the inner white matter fibers were stemmed from heterotopic gray matter. Conclusion:The results suggest that the inner heterotopic gray matter may play some role in brain function and that there is altered fiber organization in the frontal regions of BHT. ZusammenfassungZiel: Untersuchung von Anomalien der weißen Substanz bei Bandheterotopie (BHT) unter Verwendung der Diffusions-Tensor-Bildgebung (DTI). Patienten und Methodik: Eine 17-jährige Patientin mit BHT wurde gescannt, und die Faserverläufe der weißen Substanz wurden unter Verwendung von dreidimensionaler DTI-basierter Traktographie abgebildet. Ergebnisse: Fragmentierte Fasern wurden im präfrontalen Lappen und der Assoziationskortex der Patientin festgestellt. Die meisten dieser Fasern waren nicht mit denen der gesunden Kontrollen vergleichbar. Darüber hinaus gab es nur eine geringe Anzahl von Fasern im Corpus callosum, und die Mehrzahl der inneren Fasern der weißen Substanz stammte von der heterotophen grauen Substanz. Schlussfolgerung: Ergebnisse legen nahe, dass die innere heterotope graue Substanz eine Rolle bei der Hirnfunktion spielt und dass eine veränderte Faserorganisation in den frontalen Bereichen der BHT vorliegt. Schlüsselwörter: Bandheterotopie · Diffusions-Tensor-Bildgebung · Fasertraktographie · Präfrontale Funktion · Corpus callosum

Direct and Collateral Alterations of Functional Cortical Circuits in a Rat Model of Subcortical Band Heterotopia

“…But another study described similar patterns of connectivity in patients and controls, with tracts that appeared to cross or end within the band heterotopia (Eriksson et al 2002). Variability in heterotopic bands between subjects could reconcile these findings (Lu et al 2008). Another important feature to consider is the contribution of ectopic neurons to cortical function.…”

“…Clinical evidences are contradictory at this point. Investigations of fiber bundles in patients with a SBH using diffusion-tensor imaging and fiber tractography described indeed a disorganization of the main axonal tracts (Lee et al 2005;Lu et al 2008;Iannetti et al 2011). But another study described similar patterns of connectivity in patients and controls, with tracts that appeared to cross or end within the band heterotopia (Eriksson et al 2002).…”

Periventricular Nodular Heterotopia: Detection of Abnormal Microanatomic Fiber Structures with Whole-Brain Diffusion MR Imaging Tractography

“…For display purposes, an additional tractogram was also generated with 100,000 tracks for each participant using the exact same processing constraints. From a technical perspective, this whole brain tractography approach allowed us to avoid potential sources of error inherent in 'seed to target' region-of-interest-based tractography approaches where assessment of structural connectivity, and comparison to control subjects, is complicated by the absence in control subjects of structures corresponding to the ectopic clusters of neurons (27)(28)(29)(30)(31)(32). ( inferior-superior).…”