Quantitative transcranial sonography in Wilson's disease and healthy controls: Cut-off values and functional correlates

Abstract

To compare transcranial sonography (TCS) findings in patients with predominantly neurological Wilson's disease (WD) to those from controls, and to correlate TCS data with the clinical profile of WD. Patients with WD (n=40/f=18) and healthy, matched controls (n=49/f=20) were assessed in terms of TCS, serum copper and iron parameters, and clinical scales, such as the Unified Wilson's Disease Rating Scale (UWDRS), Addenbrooke's Cognitive Examination-Revised (ACE-R), Mini Mental State Examination (MMSE), and Beck Depression Inventory. Lenticular nuclei and substantia nigra echogenic area cut-off values clearly differentiated WD patients from controls (area under the curve: 95.4% and 79.4%). Substantia nigra echogenic area was significantly larger in male than in female patients (p=0.001). Compared with controls, patients showed hyperechogenicity also in thalami and midbrain tegmentum/tectum; third ventricle width was increased and midbrain axial area was reduced. In the WD group, male gender correlated with substantia nigra echogenic area (r=0.515, p=0.0007) and serum ferritin levels (r=0.479, p=0.002); lenticular nuclei hyperechogenicity correlated with dystonia (r=0.326, p=0.04) and dysarthria (r=0.334, p=0.035); third ventricle width correlated with dystonia (r=0.439 p=0.005), dysarthria (r=0.449, p=0.004), parkinsonism (r=0.527, p<0.001), UWDRS neurological and total scores (both r=0.504, p=0.0009), MMSE (r=-0.496, p=0.001), and ACE-R (r=-0.534, p=0.0004). Lenticular nuclei echogenic area allowed highly accurate discrimination between patients and controls. The gender differences in substantia nigra echogenicity and iron metabolism are of interest in further studies in WD. TCS reflects different dimensions of WD pathology clearly differentiable from healthy controls and correlating with various clinical characteristics of WD.

Keywords: Ferritin; Gender differences; Hyperechogenicity; Lenticular nucleus; Transcranial sonography; Wilson's disease.