3. Practical Illustrations

The neurodegenerative Wilson disease (NWD) is a genetic disease. It is caused by mutations in the P-type ATPase. The defect leads to abnormal copper transport and metabolism in mitochondria and causes apoptotic and necrotic cell death due to oxidative damage after excess accumulation of intercellular copper. MRI shows T₂ hyper intense lesions involving mostly the putamina and less frequently the thalamic brain stem cerebellar dentate regions and cerebral white matter. The diffusion weighted imaging (DWI) and proton magnetic resonance spectroscopy (PMRS) are very useful techniques to shed light on the pathogenesis of NWD by inspecting the microscopic water diffusion and cellular metabolism in vivo. The T₁-weighted imaging (T₁WI) shows low signal intensity and markedly high intensity on T₂-weighted imaging (T₂WI) on asymmetrical basal ganglionic lesions. Moreover there is seen increased intensity on T₂WI, of the occipital, peri-ventricular and subcortical white matter bilaterally without mass effect, suggestive of demyelination. Single voxel PMRS with voxel placed in the right putaminal lesion shows a low N-acetylaspartate/creatine ratio and a high lactate/Cr ratio, in contrast to those of bilateral occipital lobes. It is seen that impairment of copper transport across membranes leads to accumulation of copper in the liver, brain, cornea and kidney, and causes toxicity to those regions.