[1231-FP-CIT (DaTSCAN) scintigraphy in the differential diagnosis of movement disorders]

The diagnosis of idiopathic Parkinson's disease (IPD) remains mostly clinical. Nevertheless, differentiating IPD from essential tremor or other parkinsonian syndromes solely by clinical examination can be challenging in some cases, especially in the early stage of the disease. The introduction of new isotopic functional imaging techniques, and more specifically the labelling of dopamine transporter derivatives, has improved the understanding and early detection of some diseases affecting the basal ganglia. Iodine-123-FP-CIT (DaTSCAN), a (presynaptic) dopamine transporter analogue for nuclear medicine imaging, has recently been introduced for the non-invasive differential diagnosis between IPD and essential tremor or secondary (e.g. drug-related) parkinsonian syndromes. DaTSCAN scintigraphy has also demonstrated some usefulness in the evaluation of other neurodegenerative parkinsonian syndromes such as Lewy-body dementia or multiple system atrophy. For this latter however, the DaTSCAN has to be combined with a second scintigraphy, imaging the post-synaptic dopaminergic receptors, such as the D2-ligand 123I-iodobenzamide. Combining DaTSCAN scintigraphy to a functional study of the brain cortical activity using a brain perfusion scintigraphy or to the evaluation of the cardiac adrenergic system by means of a myocardial MIBG scintigraphy (a norepinephrine storage analogue) can also be helpful to refine the diagnosis. Our experience shows that a good collaboration between the neurologist specialized in movement disorders and the nuclear medicine physician is useful, if not mandatory, to optimize the diagnostic performances of DaTSCAN scintigraphy.