Transcranial sonography in movement disorders.

BACKGROUND Transcranial sonography (TCS) in the B-mode has the ability to image, infratentorial and supratentorial brain structures. For this reason, it has potential use in the diagnosis and differential diagnosis of various intracranial pathologies. METHODS AND RESULTS The authors reviewed the contribution of TCS to the differentiation of a number of neurodegenerative diseases: in parkinsonian syndromes, TCS can evaluate echogenicity changes in specific structures such as the hyperechogenic area of the substantia nigra (SN) in Parkinson's disease and the hyperechogenic caudate nucleus in Huntington's disease as well as the hyperechogenic lentiform nucleus (LN) in dystonia and Wilson's disease. In parkinson-plus syndromes, TCS may detect changes in width of the third ventricle and of the frontal horns of the lateral ventricle. The hyperechogenic SN can also be used in healthy populations as a marker of subclinical injury to the nigrostriatal system. CONCLUSION TCS is a quick, safe and non-invasive method. It could be helpful in differentiation between several movement disorders together with clinical examination and other neuroimaging methods.