Diagnostic accuracy of FP-CIT SPECT in patients with parkinsonism

Objective. To determine the diagnostic accuracy of FP-CIT SPECT in entities with and without presynaptic involvement of the nigral-striatal dopaminergic pathway in a large group of patients with movement disorders, evaluating the usefulness of quantitative analysis. Materials and methods. A group of 183 consecutive patients clinically diagnosed as either having or not having degenerative Parkinsonism. These results were then contrasted with those of FP-CIT SPECT to determine the diagnostic accuracy of the procedure. The specific binding index was evaluated with ROC curves. Results. FP-CIT SPECT was highly accurate in the diagnosis of neurodegenerative Parkinsonism (sensitivity: 95%, specificity: 90%). Most of the false positive results arose in patients with vascular Parkinsonism and the false negative results in patients with Parkinson disease. ROC curve analysis of semiquantitative evaluation had a sensitivity of 83% and specificity of 82% with an optimal cut-off of 1.44. The area under the curve was not significantly different between patients <= 60 and > 60 years (0.899 vs 0.884) of age. Conclusions: FP-CIT SPECT has a high degree of diagnostic accuracy for striatal dopaminergic involvement. No significant changes in diagnostic accuracy were seen with respect to patient age.