Insula Connections With the Parieto-Frontal Circuit for Generating Arm Actions in Humans and Macaque Monkeys.

It has been recently found that the human dorso-central insular cortex contributes to the execution and recognition of the affective component of hand actions, most likely through modulation of the activity of the parieto-frontal circuits. While the anatomical connections between the hand representation of the insula and, the parietal and frontal regions controlling reaching/grasping actions is well assessed in the monkey, it is unknown the existence of a homolog circuit in humans. In the present study, we performed a multifiber tractography investigation to trace the tracts possibly connecting the insula to the parieto-frontal circuits by locating seeds in the parietal, premotor, and prefrontal nodes of the reaching/grasping network, in both humans and monkeys.

A distinct MR imaging phenotype in amyotrophic lateral sclerosis: correlation between T1 magnetization transfer contrast hyperintensity along the corticospinal tract and diffusion tensor imaging analysis.

Background And Purpose: In the search for a diagnostic marker in ALS, we focused our attention on the hyperintense signal intensity in T1 MTC MR images along the CST, detected in some patients and not found in other patients with ALS and in control subjects. The aim of this study was to investigate the relationship between the hyperintense signal intensity in T1 MTC images and white matter damage. To this purpose, we studied potential heterogeneities in DTI values within our patients by using TBSS without a priori anatomic information.