Brain imaging in dystrophinopathies

Duchenne and Becker muscular dystrophies (DMD, BMD) are caused by genetic variants in the DMD gene coding dystrophin proteins. In addition to the impairment of muscular function, these patients also present frequent cognitive and neuropsychiatric disorders due to impaired expression of several brain dystrophins: Dp427, Dp140 and Dp71. Cerebral imaging has shed new light on the impact of dystrophinopathies on brain structure, function, and connectivity. We review the brain imaging results obtained in patients and divers animal models, showing presence of mild cortical atrophy, slight modifications of structures volumes, decreased cerebral blood flood, white matter microstructure alterations, brain hypometabolism, altered connectivity, and an abnormal cerebral response to stress. We further discuss the putative progression of cerebral disorders, and their variable severity when Dp140 expression is affected in addition to that of Dp427. Some correlations between imaging parameters and cognitive and psychological impairments have been reported but remain to be confirmed.