Exploring cortical atrophy and its clinical and biochemical correlates in Wilson's Disease using voxel based morphometry

Objectives: To determine cortical grey matter (GM) changes and their clinical and biochemical correlates in patients with Wilson’s disease using voxel based morphometry (VBM). 

Methods: Clinical and imaging data of 10 patients (all male, mean age 16.0 ± 6.3years) with Wilson’s Disease were analyzed. T1W volumetric MRI data of patients without obvious cortical atrophy or signal changes on conventional MRI was compared with MRI of 11 matched control subjects using VBM analysis with Statistical Parametric Mapping 8. Results were expressed at statistical threshold of p < 0.05 (FWE corrected) and p < 0.001 (uncorrected). Multiple regression analysis was done to analyze possible relation between GM atrophy, duration of disease and biochemical abnormalities. 

Results: Compared to controls, patients showed scattered areas of reduced GM volume in bilateral caudate head, medial part of right globus pallidus and body of right caudate (FWE corrected p < 0.05). At p < 0.001(uncorrected) widespread areas of cortical atrophy were also noted involving the frontal and temporal lobes, lentiform nuclei, cerebellum and thalamus. Significant positive correlation (uncorrected p < 0.001) were noted between (i) duration of disease and cortical GM volume of frontal, parietal and temporal lobes and cerebellum (ii) serum copper levels and GM volume of right medial frontal gyrus and paracentral lobule. 

Conclusions: To the best of our knowledge, this is the first VBM study in patients with Wilson’s disease. In spite of apparently normal cortex on visual inspection of MRI, decreased cortical GM volume was detected using VBM. In addition, serum copper may act as surrogate marker of cortical abnormalities in Wilson’s disease.