A single centre prospective study of three device-assisted therapies for Parkinson's disease

Abstract

Comparative studies assessing outcomes with the three device-assisted therapies could help to individualise treatment for patients living with Parkinson's disease. We designed a single-centre non-randomised prospective observational study assessing the quality of life (QoL), motor and non-motor outcomes at 6 and 12-months in patients treated with subcutaneous apomorphine continuous 16-hours infusion (APO), levodopa-carbidopa intestinal gel (LCIG) or subthalamic nucleus deep brain stimulation (STN-DBS). In this study, 66 patients were included (13 APO; 19 LCIG; 34 STN-DBS). At baseline, cognitive, non-motor and motor scores were significantly less severe in the STN-DBS group, whereas the LCIG group had a longer disease duration and higher non-motor scores. In the APO group, there were no statistically significant changes in non-motor, motor and QoL scales. The LCIG group had significant changes in QoL and motor scales that were significant after multiple comparison analysis at 6 and 12-months. The STN-DBS group showed improvement in QoL scores and non-motor and motor scores at 6 and 12-months after multiple comparison analysis. In this real-life prospective study, device-assisted therapies showed differences in their effects on QoL and motor and non-motor function at 12-months. However, there were also differences in baseline characteristics of the patient groups that were not based on pre-determined selection criteria. Differences in characteristics of patients offered and/or treatment with different device-assisted therapies may reflect within-centre biases that may, in turn, influence perceptions of treatment efficacy or outcomes. Treatment centres should be aware of this potential confounder when assessing and offering device-assisted treatment options to their patients and potential baseline differences need to be taken into consideration when comparing the results of non-randomised studies.

Fig. 1. The figure illustrates the process of patient selection before the commencement of device-assisted therapy.

All patients included in the study were seen at least twice in our Movement Disorders Clinic before study enrolment. Treatment was decided between the patient and treating clinician according to routine clinical care, based on factors such as patient preference and suitability for each of the treatment options in the opinion of the treating movement disorder specialist. A more detailed description of patient selection is provided in the text. DAT device-assisted therapy, APO apomorphine, LCIG levodopa-carbidopa intestinal gel infusion, STN-DBS subthalamic nucleus deep brain stimulation.

Fig. 2. The boxplots show the median and interquartile values of clinimetric assessments at baseline (blue box), 6 (green box) and 12 months (light grey box) in the APO, LCIG and DBS treatment groups.

The boxplots show the results of the statistical analysis using the Kruskal–Wallis method. The asterixis represents significant p values after Bonferroni correction (<0.05). The centre line within the box represents the median value, whereas the upper and lower interquartile ranges are represented in the upper and lower sections from the median line within the box. The whiskers represent the maximum (from the top of the box) and minimum values (from the lower part of the box), respectively. Curly brackets with asterixis are used when statistical significance was reached at 6 and 12-months. Outliers are not shown. APO apomorphine, LCIG levodopa-carbidopa intestinal gel infusion, DBS subthalamic nucleus deep brain stimulation, LEDD levodopa equivalent daily dose, PDQ 39 39 item Parkinson’s Disease Questionnaire SI, UPDRS-I, UPDRS-II, UPDRS-IV refers to the movement disorder society unified Parkinson’s disease rating scale subscores Part I (Non-motor aspects of experiences of daily living), Part II (Motor aspects of experiences of daily living) and Part III (Motor examination) respectively, UDysRS unified dyskinesia rating scale; FOG-Q new freezing of gait questionnaire, NMSS non-motor symptoms scale, QUIP-RS questionnaire for impulsive-compulsive control disorders in Parkinson’s disease, BDI Beck depression inventory, HADS Hospital anxiety and depression scale, ELF excluded letter fluency, ZCB Zarit caregiver burden scale, CSI caregiver strain index, CBI-R Cambridge behavioural inventory revised.