Cardiac sympathetic denervation is not related to nigrostriatal degeneration in Parkinson's disease.

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 (123)I-metaiodobenzylguanidine ((123)I MIBG) scintigraphy and N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-[(123)I]iodophenyl)nortropane ((123)I 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 (123)I FP-CIT single photon emission computed tomography (SPECT) followed by (123)I 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 (123)I MIBG cardiac and (123)I 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.