Cognitive profile and structural findings in Wilson's disease: A neuropsychological and MRI-based study

Background: Systematic studies on neuropsychological profile in patients with Wilson′s disease (WD) are far and few.
Aim: To examine the profile of cognitive deficits and their magnetic resonance imaging (MRI) findings in patients with WD.
Patients and Methods: Twelve confirmed patients of WD (age at onset and evaluation, 13.7±11.2 and 21.7±5.3 years, respectively; M-F ratio, 7:5) on de-coppering therapy constituted the study sample. Battery of neuropsychological tests measuring mental speed, motor speed, sustained attention, focused attention, verbal category fluency, verbal working memory, response inhibition, planning, concept formation, set-shifting ability, verbal and visual learning and memory were administered. Phenotypic details and observations on MRI of brain carried out within six months of neuropsychological assessment were documented.
Results: Neuropsychological assessment elicited cognitive deficits in multiple domains in all but one patient, who had normal MRI. Percentage of patients in the deficit range in various domains included: motor speed: 73%; verbal working memory, sustained and focused attention: 50%; verbal learning: 42%; visuo-constructive ability, verbal memory, mental speed: 33%-34%; verbal fluency, set-shifting ability, visual memory, verbal memory: 25%-27%; and verbal recognition: 17%. MRI was normal in three patients, and revealed variable abnormalities in the remaining: cerebral atrophy in 3; brainstem atrophy in 2; signal changes in basal ganglia in 9; and brainstem signal changes in 5. None had subcortical white matter changes. Two patients with normal MRI showed cognitive deficits.
Conclusion: This study provides insight into the complex cognitive and brain changes observed on MRI in WD. Use of advanced MRI techniques in a larger cohort may improve understanding regarding functional and structural brain changes observed in similar disorders.