Impact of dopamine transporter SPECT using 123I‐Ioflupane on diagnosis and management of patients with clinically uncertain parkinsonian syndromes

Imaging with (123)I-Ioflupane single-photon emission computed tomography (SPECT) is a marker of nigrostriatal neuronal integrity, allowing differentiation of parkinsonism with loss of dopaminergic terminals (presynaptic Parkinson syndrome PS) from parkinsonism without nigrostriatal degeneration. This study assessed SPECT imaging in 118 patients with clinically uncertain parkinsonian syndromes (CUPS). In 36% of patients with presynaptic PS and 54% with nonpresynaptic PS, imaging results were not consistent with the initial diagnosis. After imaging, diagnosis was changed in 52% of patients. All patients with a final diagnosis of presynaptic PS had an abnormal image, whereas 94% of patients with nonpresynaptic PS had a normal scan. Imaging increased confidence in diagnosis, leading to changes in clinical management in 72% of patients. Consequently, visual assessment of (123)I-Ioflupane SPECT may have a significant impact on the clinical management of CUPS patients.