Transcranial sonography in movement disorders: an interesting tool for diagnostic perspectives

Transcranial sonography has become an important tool for the diagnosis of various movement disorders. In most patients with idiopathic Parkinson disease, a markedly hyperechogenic substantia nigra (SN) was detected on at least one side. We have highlighted the sonographic features that might help the differential diagnosis of PD and other movement disorders. Our investigation involved 30 patients (age 45-85 years) with idiopathic Parkinson disease, 2 multiple system atrophy, 3 progressive supranuclear palsy and 2 patients with restless legs syndrome. In accordance with several previous studies, we detected hyperechogenicity of the SN by TCS in 90% of patients with idiopathic Parkinson disease. Subjects with a marked severity disease had a larger extent of the hyperechogenic SN signal. All progressive supranuclear palsy patients had an enlarged third ventricle and, in two cases, we observed the presence of hyperechoic areas in the lentiform nucleus. This last ultrasonographic feature was also seen in our patients with multiple system atrophy. TCS abnormalities of the SN, midbrain raphe and basal ganglia are characteristics of several movement and affective disorders. These features are less easily detected by other techniques, such as CT and MRI, which enable the exclusion of structural lesions, such as tumours and multi-infarct disease, because the physical principle differs from other imaging methods.