Objective: To report an exceptional case of advanced Parkinson’s disease (PD) where levodopa/carbidopa/entacapone intestinal gel (LECIG) failed to provide adequate motor control, ultimately requiring a return to continuous subcutaneous apomorphine infusion (CSAI) to bypass severe presynaptic denervation.

Background: Continuous drug delivery systems, such as LECIG and CSAI, are designed to provide continuous dopaminergic stimulation. However, their efficacy depends on different mechanisms: levodopa requires functional presynaptic terminals for conversion to dopamine, whereas apomorphine acts directly on postsynaptic receptors.

Method: A 75-year-old woman with advanced PD, previously well-controlled on CSAI and oral levodopa, developed generalized subcutaneous nodules, forcing the discontinuation of apomorphine. Transition to oral therapy (levodopa, opicapone, and dopamine agonists) resulted in near-permanent “OFF” states despite multiple adjustments. Consequently, LECIG was initiated.

Results: While the initial nasoduodenal phase was successful (video will be provided), the patient developed a catastrophic clinical picture two weeks after PEG placement: Continuous Biphasic Dyskinesia: The patient experienced unrelenting, severe involuntary movements accompanied by profound psychological distress and anxiety (video will be provided). Failure of High-Dose Levodopa: Despite escalating the LECIG dose to 4 grams of levodopa per day, the “OFF” periods and biphasic transitions could not be resolved. Successful Rescue: Due to the clinical emergency, LECIG was discontinued, and CSAI was reintroduced (8 mg/h 24 h infusion), managing skin sites carefully, alongside oral levodopa (400 mg every 4 h) and opicapone. Follow-up: This combination successfully restored motor stability and resolved the dyskinesias. The improvement has been sustained for over one year.

Conclusion: This case illustrates a critical pharmacological threshold in advanced PD. We hypothesize that the patient’s extreme presynaptic denervation rendered even high-dose continuous levodopa (LECIG) insufficient to cross the therapeutic threshold for stable motor control. In such very advanced cases, direct postsynaptic stimulation via apomorphine may be a viable mechanism to bypass the lack of endogenous levodopa-to-dopamine conversion and storage capacity.

« Back to 2026 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/when-presynaptic-stimulation-is-not-enough-severe-biphasic-dyskinesia-on-lecig-reversed-by-postsynaptic-apomorphine-rescue/