DaTSCAN® dilution with 0.9% NaCl - A stability evaluation

123I-ioflupane (DaTSCAN®, GE) is a well-known ready-to-use radiopharmaceutical employed as a visualizing tool of the brain dopamine transporter receptor distribution. According to the Summary of Product Characteristics recommendations, we evaluated the stability of the DaTSCAN® after a 0.9% sodium chloride solution dilution. No significant increase in free 123I-iodide was revealed between diluted and undiluted samples over a 1-h timeframe. This stability in sodium chloride can compensate for potential dilution error and offers a suitable alternative method for syringing DaTSCAN®.

Analysis of retinal nerve layers in idiopathic, LRRK2-associated Parkinson's disease and unaffected carriers of G2019S mutation

INTRODUCTION

In both prodromal and early symptomatic stages of idiopathic PD (iPD) peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell layer (mGCL) thinning have been identified. Here we assessed whether these alterations can also be detected in symptomatic and presymptomatic stages of LRRK2-PD.

METHODS

218 eyes belonging to 20 iPD, 19 LRRK2-PD (L2PD), 24 LRRK2 non-manifesting carriers (L2NMC), and 46 controls (HCs). pRNFL, mGCL thickness (squares), and Bruch's membrane opening minimum rim width were evaluated by SD-OCT. In L2NMC, ¹²³I-ioflupane SPECT (DaT-SPECT) with semi-quantitative analysis was carried out.

RESULTS

Compared to HCs, iPD patients showed significant thinning of the temporal (BMO-MRW and pRNFL), superior-temporal (BMO-MRW), inferior-temporal (BMO-MRW), superior-nasal (BMO-MRW) and central sectors (BMO-MRW) (p < 0.05), as well as in five mGCL sectors (p < 0.05). No significant differences were found between the L2PD or L2NMC and HCs. BMO-MRW thickness in its temporal-superior, superior-nasal and middle sectors was influenced by disease duration (p < 0.05) and mGCL thickness in sectors TS1, TS2, TS3, NS1 and NS3 was influenced by UPDRSIII and age (p < 0.05).

CONCLUSION

LRRK2-PD is distinguished from iPD by absent or less retinal nerve involvement, both in clinical and preclinical stages.