In recent years, TCS has become widely accepted and used in the early and differential diagnosis of Parkinson’s disease. One hallmark of this method, besides its inexpensiveness and non-invasive character, is the ability to discriminate between essential tremor, Parkinson’s disease related tremor and the differentiation of atypical Parkinson syndromes [3], [4] and [5]. In PD, the typical finding is a hyperechogenicity
of the SN, which is normally more pronounced contralateral to the clinically more affected side [6]. This hyperechogenicitiy seems to stay constant during the course of the disease and patho-anatomical investigations R428 chemical structure revealed that it most likely reflects increased iron content, as was shown in animal experiments, as well as in post mortem of brains [7], [8], [9] and [10]. In patients with atypical signs in Parkinson syndromes TCS is useful for assignment to the idiopathic forms. Patients with multi system atrophy, or supranuclear palsy of the Richardson subtype do normally not display a hyperechogenic SN, but rather show increased echogenicity
of the lenticular nucleus [5]. In contrast, patients with corticobasal degeneration commonly display a hyperechogenic SN in combination with hyperechogenicity in the lenticular nucleus [11]. In clinical practice, B-mode sonography proved also to be useful for discrimination of IPS from other movement or gait disorders, isocitrate dehydrogenase inhibitor such as normal pressure hydrocephalus or other disorders associated with metal accumulation in the basal ganglia. B-mode sonography allows the visualization of the ventricular system, especially
the third ventricle and the side ventricles. Thus, in patients with an unclear gait disorder the differential diagnosis of a normal pressure hydrocephalus can be ruled out easily [12]. Due to the fact, that iron accumulation is proposed to be the anatomical correlation of the SN hyperechogenicity in Parkinson’s disease, TCS was also studied in other movement disorders related to metal accumulation. For example, it was found, that the lenticular nucleus displays increased echogenic values in patients suffering from Wilson’s disease, before a disorder with copper accumulation in and outside the brain. The intensity of hyperechogenicity correlates with disease severity [13]. In patients with cervical and upper limb dystonia TCS displays increased lenticular nucleus echogenicity pronounced contra lateral to the clinically affected side [14] and [15]. As hyperechogenicity in the parenchymal sonography was believed to be due to metal accumulation, a post mortem analysis was performed in individuals suffering from dystonia. This study could rule out an increased copper and manganese content in the lenticular nucleus compared to controls [16].