Comparison of Dopamine Transporter SPECT and 123I-MIBG Myocardial Scintigraphy to Assess Clinical Severity in Patients With Parkinson Disease.

Purpose: The aim of our study was to evaluate the use of dopamine transporter (DAT) SPECT and I-MIBG myocardial scintigraphy to determine the clinical severity of Parkinson disease (PD), with a focus on motor impairments affecting activities of daily living (ADLs).

Methods: Data for 65 consecutive PD patients who underwent both DAT and MIBG imaging were reviewed. Associations between imaging variables and Hoehn and Yahr (H&Y) staging or self-supportive care ratings were investigated. Univariate and multivariate regression analyses were performed to determine the factors associated with ADLs.

Results: After applying the exclusion criteria, 45 patients were analyzed (age, 73.1 ± 9.3 years; 23 males; H&Y stage 1: n = 12, stage 2: n = 14, stage 3: n = 10, stage 4: n = 5, and stage 5: n = 4; self-supportive care rating-dependent ADLs: n = 29). Dopamine transporter variables were significantly associated with the clinical severity of PD as assessed by H&Y staging, whereas MIBG variables were not. Dopamine transporter variables gradually decreased throughout progressive stages, whereas the MIBG variables changed only in the advanced stages. In a multivariate analysis including clinical and imaging variables, both lower DAT and MIBG uptakes were significantly associated with dependent ADL status (P = 0.028 and 0.034, respectively).

Conclusions: In patients with PD, DAT SPECT and MIBG myocardial scintigraphy were associated with ADL status; DAT SPECT was a stronger indicator of severity than MIBG myocardial scintigraphy in the early and middle stages.