Molecular imaging studies in Parkinson's disease: reducing diagnostic uncertainty

• Grant number: 08/05841-5
• Support type: Regular Research Grants - Publications - Scientific article
• Duration: July 01, 2008 - May 31, 2009
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal researcher: Henrique Ballalai Ferraz
• Grantee: Henrique Ballalai Ferraz
• Home Institution: Departamento de Neurologia e Neurocirurgia. Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The diagnosis of Parkinson's Disease (PD) is based on clinical criteria but misdiagnosis is as high as 25% of cases as confirmed by anatomic-pathological studies. Since the introduction of in vivo molecular imaging techniques using Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), the diagnosis of PD became more reliable by assessing dopaminergic and even non-dopaminergic systems. The purpose of this article is to critically review the current data on molecular neuroimaging focusing on the nigrostriatal circuitry and providing useful information on the role of these new imaging techniques in the management of clinically unclear cases of PD. Patients with essential tremor, psychogenic parkinsonism or drug-induced parkinsonism can be differentiated from PD in doubtful situations using molecular imaging techniques evaluating striatal dopamine transporters (DAT). However, in patients with vascular parkinsonism, atypical parkinsonism and parkinsonism associated with dementia DAT scans have less diagnostic usefulness. Scans with non-DAT tracers (i.e. D2 dopamine receptors) are necessary together with long-term clinical follow-up, and re-scans to improve diagnostic accuracy. (AU)