Widespread white matter changes in Kennedy disease: a voxel based morphometry study

Objective: X linked spinobulbar muscular atrophy (Kennedy disease (KD)), which is clinically characterised mainly by neuromuscular and endocrine symptoms, has to be considered as a multisystem disorder. Based on clinical evidence of central nervous system involvement, potential KD associated cerebral volume alterations were analysed in vivo. Methods: Whole brain based analysis of optimised voxel based morphometry (VBM) was applied to three dimensional MRI data from 18 genetically confirmed KD patients and compared with age matched controls. Results: Subtle decreases in grey matter volume, mainly localised in frontal areas, were found, but extensive white matter atrophy was observed, particularly in frontal areas, but also involving multiple additional subcortical areas, the cerebellar white matter and the dorsal brainstem from the midbrain to the medulla oblongata. Conclusion: The VBM results demonstrated a morphological correlate of central nervous system involvement in KD, in agreement with aspects of the clinical phenotype (behavioural abnormalities, central–peripheral axonopathy) and with pathohistological findings.