Relationships of drooling with motor symptoms and dopamine transporter imaging in drug-naïve Parkinson's disease

Abstract

Objectives: The aim of the present study was to determine the relationships of drooling with motor symptoms and nigrostriatal neuron loss in drug-naïve patients with Parkinson's disease (PD). We therefore examined the relationships of drooling with motor symptoms and striatal dopamine transporter (DAT) binding measured by [123-Iodine]-fluoropropyl-2beta-carbomethoxy-3beta-(4-iodophenylnortropane) dopamine transporter single-photon emission computed tomography(¹²³I-FP-CIT SPECT).

Patients and methods: Thirty-five untreated PD patients (14 men and 21 women with a mean age of 71.9 ± 7.2 years) were included in this study. The patients were divided into a drooler group and non-drooler group. They underwent clinical assessments and ¹²³I-FP-CIT SPECT imaging. Motor symptoms were assessed using Unified Parkinson's Disease Rating Scale (UPDRS).

Results: The results showed that UPDRS motor score (p = 0.002) and akinetic-rigid score (p = 0.008) were higher and that striatal DAT availability (p = 0.03) was lower in the drooler group than in the non-drooler group. However, tremor score, age, and duration of PD showed no significant differences between the drooler group and non-drooler group.

Conclusions: Drooling in untreated PD is related to an increase in motor symptoms (especially bradykinesia and axial symptoms) and to reduction of striatal DAT availability.

Keywords: Dopamine transporter imaging; Drooling; Parkinson’s disease; Unified parkinson’s disease rating scale.