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

Abstract

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.