Antero-Ventral Internal Pallidum Stimulation Improves Behavioral Disorders in Lesch-Nyhan Disease

As limitation of this study, the number of subjects is still small. Moreover, we used clinical criteria for diagnosis and did not have pathologic confirmation. Further studies including pharmacological testing with larger groups of patients and with neuropathologic correlation are needed to determine accurate diagnostic values. There are other new diagnostic methods, which can be used for the early differential diagnosis of parkinsonian syndromes. Especially MRI studies could demonstrate promising results with sensitivity and specificity values over 90% (Paviour et al.17,18 and Blain et al.16) Nevertheless it has to be noted that the mentioned studies included patients with an already long duration of disease (4.5–13.3 years) From our present pilot study, we propose that pupillography with PDD measurement can offer a simple method differentiating PSP from other parkinsonsian syndromes in early stages. Further investigations have to be performed to support this pilot study.