Clinical Outcomes and Predictors of Response to Levodopa–Entacapone–Carbidopa Intestinal Gel in Advanced Parkinson’s Disease: A Retrospective Cohort Study over a 4-Year Period

Background/Objectives: Advanced Parkinson’s disease is characterized by severe motor fluctuations and disabling dyskinesias that often become refractory to conventional oral dopaminergic therapies. Methods: This study aimed to evaluate the clinical efficacy of levodopa–entacapone–carbidopa intestinal gel (LECIG) in 50 patients initiated during a four-year period at a tertiary movement disorders center. Motor outcomes were analyzed using Wilcoxon signed-rank and McNemar’s tests, while multivariable logistic regression was employed to identify predictors of improvement. Results: LECIG initiation significantly reduced mean daily OFF time from 4.63 ± 0.75 to 1.62 ± 1.97 h (p < 0.0001) and total dyskinesia duration by 65% (p < 0.0001). Furthermore, the prevalence of early morning akinesia decreased from 80% to 26%, and delayed ON phenomena were completely eliminated (p < 0.0001). Subgroup analyses indicated that patients with troublesome dyskinesia (≥1 h/day) achieved significantly greater reductions in involuntary movements compared to those with lower baseline dyskinesia levels (p = 0.013). Conclusions: These findings suggest that LECIG provides a meaningful and sustained stabilization of motor complications, highlighting its role as a valuable device-aided therapy in managing advanced Parkinson’s disease.