Asymmetric dystonia with frontal white matter lesions in Wilson's disease

Asymmetrical manifestation of dystonia was investigated in 26 patients with Wilson's disease with modified dystonia rating scale and correlated with the asymmetricity of CT and/or MRI findings. Ten patients (eight men and two women) had dystonia. The age of disease onset ranged from 11 to 30 years with a mean of 18.6 ± 5.2 years. The duration of the illness was from 2 to 15 years (mean 7.0; S.D. 3.6). Six patients had subcortical white matter lesions in the frontal and/or parietal lobes, as well as lesions in the basal ganglia. Five patients, who had asymmetrical white matter lesions in the frontal lobes and symmetrical lesions in the basal ganglia and the thalamus, developed more severe contralateral dystonia. The other four patients with symmetric lesions in the basal ganglia and the thalamus had nearly-symmetrical dystonia. One patient with symmetrical lesions in the frontal lobes and the basal ganglia also had symmetrical manifestation of dystonia. We suggest that the interruption of the loop between the thalamus and premotor cortex by subcortical white matter lesions may enhance contralateral dystonia.