Revista chilena de neuro-psiquiatría
On-line version ISSN 0717-9227
DIAZ, Fernando; MENA, Ismael and GOMEZ, Ariel. Early Diagnosis of Parkinson's Disease: NeuroSPECT of the Dopamine Transporter. Rev. chil. neuro-psiquiatr. [online]. 2002, vol.40, n.3, pp. 243-252. ISSN 0717-9227. doi: 10.4067/S0717-92272002000300006.
Background. We recently reported that NeuroSPECT (NSP) scanning of the dopamine transporter (DAT) is a highly sensitive method for early diagnosis of Parkinson's disease (26). Objectives. To evaluate the sensitivity of NSP of DAT in patients with de novo hemiparkinsonism, to compare the contralateral and ipsilateral symptoms, and to contrast these with healthy control subjects in order to assess the sensitivity of this tool for detecting pre-symptomatic and symptomatic impairment of DAT concentration. Material and methods. The present study includes 20 de novo patients with hemiparkinsonism (HP). The UPDRS (V) was 1, mean evolution was 3.0 years, and mean age was 60.3; 5/20 were females. The average UPDRS (III) was 14, eight HP were left and 12 HP were right. The patients were compared with 28 healthy subjects of which 21 were females and the mean age was 54. Three-dimensional images of the DAT distribution in the brain were gathered four hours after IV injection of 30 mCi of Trodat-1 Tc 99m. Results. In normal subjects, there is maximal concentration of DAT in the caudate and putamen. We establish a comparison with the occipital cortex, where there is a mild nonspecific concentration of DAT. In 20 patients with de novo HP, there was a significant decrease in DAT concentration in comparison with the cortical reference. This abnormality was bilateral, predominantly in the contralateral nucleus of the symptomatic side. The sensitivity of the putamen to detect de novo Parkinson's Disease was 90%, and the specificity was 91%. In 25 out of 28 of the control subjects, there was a markedly higher concentration of DAT in the caudate and putamen in comparison with the cortical reference. Conclusion. The high sensitivity of NSP of Trodat-1 Tc99m in patients diagnosed with symptomatic hemiparkinsonism is also seen in its early detection of abnormalities in the contralateral nucleus of the asymptomatic side, albeit of lesser degree, in the pre-symptomatic stage
Keywords : Parkinson's Disease; dopamine transporter; NeuroSPECT; Trodat Tc99m; hemiparkinsonism.