“…DTI and fiber tracking have been applied to study cerebellar–corticomotor networks in a number of ataxic conditions ( Habas and Cabanis, 2007 ; Kitamura et al, 2008 ; Pagani et al, 2010 ; Prodi et al, 2013 ; Rizzo et al, 2011 ; Solodkin et al, 2011 ; Ying et al, 2009 ; Yoon et al, 2006 ) other than A–T. Although histopathological evidence for collective atrophy in pontocerebellar pathways ( Verhagen et al, 2012 ), altered evoked potentials and myelinated fiber loss in spinal cord sensory pathways ( Aguilar et al, 1968 ; Boder and Sedgwick, 1958 ; De Leon et al, 1976 ; Dunn, 1973 ; Scarpini et al, 1996 ; Sourander et al, 1966 ; Stritch, 1966 ), and demyelination of corticospinal tracts (CST) has been reported in A–T ( Agamanolis and Greenstein, 1979 ; Verhagen et al, 2012 ), these findings relate to post-mortem studies, usually at the end stages of disease. dMRI studies that employ probabilistic tractography to analyze WM pathway integrity and connectivity to multiple brain regions is urgently required to fully understand the impact of the ATM gene mutation on A–T motor circuits.…”