The aim of this study is to assess the effect of LCIG (levodopa-carbidopa intestinal gel) on HRQL (Health-Related Quality of Life) of participants and compare the Health-Related Quality of Life between participants continuing to levodopa-carbidopa intestinal gel treatments versus participants continuing on oral therapy for Parkinson's Disease.

Parkinson's disease (PD) is the second most common neurodegenerative disorder in the world. It can be treated sufficiently until motor complications with fluctuations of mobility and dyskinesia develop. The quality of life is relentlessly deteriorating with longer disease duration once the complications of conservative oral therapy develop. Continuous dopaminergic stimulation using Levodopa/Carbidopa Intestinal Gel (LCIG) improves the motor complications of Parkinson's disease and preliminary data suggest that also the quality of life is improved. Primary Objective is to assess the effect of LCIG on Health Related Quality of Life (HRQL) of patients according to selection criteria from German guidelines and compare improvement in HRQL between patients continuing to LCIG treatment and patients staying on oral treatment, despite being eligible according to these guidelines. In addition, current selection criteria recommended by the national guideline will be documented at baseline.

Inclusion Criteria:

• Eligibility for LCIG according to current version of the Summary of Product Characteristics of LCIG of the respective country (Germany, Switzerland).
• Decision to treat with LCIG or other medication made by the study physician prior to any decision to approach the patient to participate in this study.
• Unchanged available combinations of PD medicinal treatment for at least one week prior to study inclusion.
• Patient has given written informed consent.

Exclusion Criteria:

• Contraindication to LCIG according to current version of the German SmPC or Swiss SmPC.
• Contraindication to placement of intrajejunal PEG-J tube.
• Current treatment with Deep Brain Stimulation (DBS), Apomorphine pump or LCIG
• Severe dementia based on a Mini-Mental State Examination (MMSE) of < 10
• Acute psychotic disorder (benign hallucinations or earlier psychotic episodes are not an exclusion criterion)
• Depression with suicidal thoughts (earlier episodes of major depression are not an exclusion criterion)
• History or presence of any condition that might interfere with absorption, distribution, metabolism, or excretion of LCIG
• Drug or alcohol addiction (drug addiction: continuous or sporadic use of drugs without medical indication or with paradoxical medical indication or in inappropriate amounts. Addictive consumption of e.g. alcohol, cannabis, amphetamine, sniffing agents, cocaine, heroin, crack). Alcohol addiction male: > 40 g/day; female: > 30 g/day)
• Illiteracy or insufficient language skills to complete the questionnaires

Advanced Parkinson Disease