Motor Complications and Pharmacological Management in Parkinson's Disease

Parkinson’s disease is characterised by progressive dopaminergic neuron loss, for which levodopa remains the principal symptomatic therapy. Chronic levodopa use frequently leads to motor complications, notably dyskinesias and motor fluctuations, which impair patient quality of life and complicate long-term management. Motor fluctuations encompass wearing-off—an earlier return of parkinsonian symptoms before the next dose—and the on-off phenomenon, with sudden shifts between mobility and immobility. Dyskinesias manifest as involuntary, often choreiform movements that can be dose-related or unpredictable. The emergence of these complications is influenced by levodopa dose, duration of therapy, patient age and phenotype. Pharmacological strategies aim to smooth dopaminergic stimulation: fractionated levodopa dosing, adjunctive dopamine decarboxylase inhibitors to reduce peripheral metabolism, catechol-O-methyltransferase and monoamine oxidase B inhibitors to prolong half-life, and amantadine for dyskinesia suppression. Novel delivery systems—such as continuous intestinal infusion—and personalised regimens guided by predictive algorithms are under evaluation to minimise motor complications and optimise functional outcomes across diverse patient populations.

Research from Nature Portfolio

Recent studies have leveraged large-scale data and advanced analytics to stratify dyskinesia risk and guide management. One investigation applied machine-learning algorithms to clinical and neuroimaging features from a well-characterised cohort, demonstrating that a Random Forest classifier could predict future dyskinesia with over 90 per cent accuracy using a small set of predictors, including baseline levodopa exposure and motor severity. The derived decision tree offers a potential framework for tailoring initial treatment intensity. In parallel, longitudinal neuropsychological research has identified executive and attentional dysfunction as independent predictors of levodopa-induced dyskinesia, suggesting that cortical network integrity influences susceptibility. These findings support the integration of cognitive profiling into therapeutic decision-making and the development of multidisciplinary interventions to mitigate long-term motor complications.

Motor Complications and Pharmacological Management in Parkinson's Disease publication trend

The graph below shows the total number of articles in motor complications and pharmacological management in parkinson's disease across all publications each year (not limited to Nature Index journals).

Technical terms

Dyskinesia: Involuntary, often choreiform movements arising primarily during peak levodopa effect.

Motor fluctuations: Variations in motor performance alternating between ‘on’ periods of adequate mobility and ‘off’ periods of bradykinesia or rigidity.

Wearing-off: A type of motor fluctuation in which the therapeutic effect of a levodopa dose diminishes before the next scheduled dose.

On-off phenomenon: Sudden and unpredictable shifts between mobile (‘on’) and immobile (‘off’) states, often unrelated to dosing schedule.

Dopamine decarboxylase inhibitor (DCI): An agent (e.g. carbidopa or benserazide) co-administered with levodopa to prevent peripheral conversion to dopamine and increase central availability.

References

1. Levodopa-induced motor complications associated with benserazide and carbidopa in Parkinson’s disease: a disproportionality analysis of the FAERS database. Frontiers in Pharmacology (2025).
2. Prediction of dyskinesia in Parkinson’s disease patients using machine learning algorithms. Scientific Reports (2023).
3. Risk factors of levodopa-induced dyskinesia in Parkinson’s disease: results from the PPMI cohort. npj Parkinson's Disease (2018).
4. Cognitive impairment and levodopa induced dyskinesia in Parkinson’s disease: a longitudinal study from the PACOS cohort. Scientific Reports (2021).