Aim
The aim of our study was to investigate the relationship between myocardial sympathetic degeneration and nigrostriatal impairment in patients affected by Parkinson’s disease (PD) by means of 123I-metaiodobenzylguanidine (123I MIBG) scintigraphy and N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-[123I]iodophenyl)nortropane (123I FP-CIT) scintigraphy.
Patients and methods
The study involved 37 patients with clinical diagnosis of PD (22 males and 15 females, mean age 62 years (±10), evaluated with 123I FP-CIT single photon emission computed tomography (SPECT) followed by 123I MIBG scintigraphy within 20 (±3) days. Early and delayed anterior chest images were acquired and the heart/mediastinum ratio (H/M ratio) was calculated. Furthermore, the population has been divided on the basis of the main clinical pattern to investigate the possible role of a tremor-dominant or an akinetic-dominant phenotype in this comparison.
Results
In PD population, there were no statistical relationships between early and delayed 123I MIBG cardiac and 123I FP-CIT striatal uptake in contralateral caudate (P > 0.05) and in contralateral putamen (P > 0.05) to the side mainly affected; no statistically significant relationships have been found at any level when considering ipsilateral striatum. We did not find statistically significant relationships when considering the single PD phenotypes.
Conclusions
The results of our study suggest that cardiac sympathetic system and nigrostriatal system are differently affected in PD. In particular, the sympathetic neurodegeneration rate is not related to nigrostriatal degeneration rate and vice versa in our series as detectable scintigraphically.