Do MRI features distinguish Wilson's disease from other early onset extrapyramidal disorders? An analysis of 100 cases.

Magnetic resonance imaging (MRI) is frequently used in the evaluation of various extrapyramidal disorders. Among the plethora of MRI features in Wilson's disease (WD), only "face of the giant panda" sign has been recognized to distinguish WD from other early onset extrapyramidal disorders (EOEPD). To ascertain the value of various MRI features in differentiating neuropsychiatric form of WD from other EOEPD. This retrospective analysis included 100 patients (M:F = 56:44) of EOEPD (5-40 years), who had undergone MRI during Jan'03 to Nov'08. Their clinical features were recorded and the following MR sequences were analyzed: T1WI, T2WI, FLAIR. Fifty-six patients had WD (M:F = 28:30, age at onset: 14 +/- 6.8 years) and 44 had other EOEPD (M:F = 27:17, age at onset: 19 +/- 9.8 years) that included Huntington's disease--4, young-onset Parkinson's disease--7, mitochondrial disorders--2, Hallervorden-Spatz disease--8, non-Wilsonian hepatolenticular degeneration--2, toxic/metabolic disorder--1, and others--20. The duration of illness at the time of MRI was comparable (WD: 3.1 +/- 4.9 years; Other EOEPD: 2.8 +/- 2.4 years). MR signal characteristics varied in topography and severity in both the groups. All the patients of WD had signal abnormalities in MRI, as against 16/44 of the other EOEPD group. The following MR observations were noted exclusively in WD: "Face of giant panda" sign (14.3%), tectal plate hyperintensity (75%), central pontine myelinolysis (CPM)-like abnormalities (62.5%), and concurrent signal changes in basal ganglia, thalamus, and brainstem (55.3%). Besides "Face of giant panda" sign, hyperintensities in tectal-plate and central pons (CPM-like), and simultaneous involvement of basal ganglia, thalamus, and brainstem are virtually pathognomonic of WD.