What was first and what is next in selecting device-aided therapy in Parkinson's disease? Balancing evidence and experience

Vital nutrition: enhancing health in advanced Parkinson's disease with device-aided therapies

Patients with advanced Parkinson's disease (PD) face a variety of nutritional challenges, including dysphagia, malnutrition, impaired absorption, gastrointestinal issues, and adverse drug interactions, in addition to body weight fluctuations. These challenges are especially significant for those utilising device-aided therapies (DATs), requiring personalised management strategies. Integrating dietitians into the multidisciplinary team (MDT) is vital for optimising nutrition, enhancing medication efficacy, and managing symptoms. This paper outlines strategies for supporting advanced PD patients using DATs, highlighting the critical role of dietitian assessments. Although there is no one-size-fits-all solution, dietary interventions are essential for improving motor function, preventing complications, and promoting overall health.

Foslevodopa/Foscarbidopa: A Review in Advanced Parkinson's Disease

Foslevodopa/foscarbidopa [PRODUODOPA® (EU); VYALEV™ (USA, Canada, Japan)] is a soluble formulation of levodopa and carbidopa prodrugs for 24-h continuous subcutaneous (SC) infusion. It is approved for the treatment of motor fluctuations in patients with advanced Parkinson's disease (PD). Administered via an ambulatory infusion pump, it allows for personalized dosing based on individual needs. In a randomized, double-blind, double-dummy trial, continuous SC infusion of foslevodopa/foscarbidopa provided a significant and clinically meaningful increase in hours of 'on' time without troublesome dyskinesia and a reduction in hours of 'off' time compared with oral immediate-release levodopa/carbidopa. The benefits of foslevodopa/foscarbidopa were maintained over the longer term (up to 124 weeks). Continuous SC infusion of foslevodopa/foscarbidopa was generally well tolerated, including over the longer term. However, infusion site events were common, necessitating regular monitoring, cannula replacement, infusion site rotation and aseptic techniques. Although further long-term data are required, foslevodopa/foscarbidopa represents a promising non-surgical alternative to the available device-aided therapies for patients with advanced PD whose motor fluctuations are inadequately controlled by other oral PD medications.

Device-aided therapies (DATs) in Parkinson's disease (PD). The DATs-PD GETM Spanish Registry Protocol Study

BACKGROUND AND OBJECTIVE

Device-aided therapies (DATs) are treatments indicated for people with Parkinson´s disease (PwP) experiencing clinical fluctuations that remain suboptimal despite conventional medication. New DATs have recently emerged such as levodopa-entacapone-carbidopa intestinal gel infusion (LECIG) and subcutaneous infusion of foslevodopa/foscarbidopa (fLD/fCD). Understanding the differences between various DATs is essential.

PATIENTS AND METHODS

We present here the protocol study of the DATs-PD GETM Spanish Registry. This is a descriptive, observational, prospective, multicenter, open study that is proposed as a clinical registry with progressive inclusion of PwP treated with a DAT in daily clinical practice conditions in more 40 centers from Spain for 10 years. The principal aim is to know the type of DAT that PwP in our country (Spain) receive. Specific objectives are to compare the clinical characteristics of the patients, the effectiveness, safety and tolerability, to identify predictors of a good response and to analyze the response by groups (gender, disease duration, phenotype, etc.). There is a baseline visit (V1; indication of the therapy), start visit (V2; initiation of the therapy) and follow-up visits at 6 months ±  3 months (V3_6M) and after this annually ±  3 months for 10 years (V3_12M, V3_24M, etc.).

RESULTS

The registry is on going. The first patient was included on April 10, 2024. Patient recruitment and follow-up will be conducted until 31/DEC/2033. It is estimated that the registry will include a minimum of 3,000 patients.

CONCLUSION

The present study will help improve the care of PD patients treated with a DAT.

Use of the MNCD Classification to Monitor Clinical Stage and Response to Levodopa-Entacapone-Carbidopa Intestinal Gel Infusion in Advanced Parkinson's Disease

BACKGROUND AND OBJECTIVE

Staging Parkinson's disease (PD) with a novel simple classification called MNCD, based on four axes (Motor; Non-motor; Cognition; Dependency) and five stages, correlated with disease severity, patients' quality of life and caregivers' strain and burden. Our aim was to apply the MNCD classification in advanced PD patients treated with device-aided therapy (DAT).

PATIENTS AND METHODS

A multicenter observational retrospective study of the first patients to start the levodopa-entacapone-carbidopa intestinal gel (LECIG) in Spain was performed (LECIPARK study). The MNCD total score (from 0 to 12) and MNCD stages (from 1 to 5) were collected by the neurologist at V0 (before starting LECIG) and V2 (follow-up visit). Wilcoxon's signed rank and Marginal Homogeneity tests were applied to compare changes from V0 to V2.

RESULTS

Sixty-seven PD patients (58.2% males; 69.9 ± 9.3 years old) with a mean disease duration of 14.4 ± 6.5 years were included. The mean treatment duration (V2) was 172.9 ± 105.2 days. At V0, patients were classified as in stage 2 (35.8%), 3 (46.3%) or 4 (17.9%). The frequency of patients in stage 4 decreased to 9% at V2 (p = 0.001). The MNCD total score decreased from 6.27 ± 1.94 at V0 to 5.21 ± 2.23 (p < 0.0001). From V0 to V2, the motor (M; p < 0.0001) and non-motor symptom (N; p < 0.0001) burden decreased, and autonomy for the activities of daily living (D; p = 0.005) improved.

CONCLUSIONS

The MNCD classification could be useful to classify advanced PD patients and to monitor the response to a DAT.

A Computational Model of Deep Brain Stimulation for Parkinson's Disease Tremor and Bradykinesia

Parkinson's disease (PD) is a progressive neurological disorder that is typically characterized by a range of motor dysfunctions, and its impact extends beyond physical abnormalities into emotional well-being and cognitive symptoms. The loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) leads to an array of dysfunctions in the functioning of the basal ganglia (BG) circuitry that manifests into PD. While active research is being carried out to find the root cause of SNc cell death, various therapeutic techniques are used to manage the symptoms of PD. The most common approach in managing the symptoms is replenishing the lost dopamine in the form of taking dopaminergic medications such as levodopa, despite its long-term complications. Another commonly used intervention for PD is deep brain stimulation (DBS). DBS is most commonly used when levodopa medication efficacy is reduced, and, in combination with levodopa medication, it helps reduce the required dosage of medication, prolonging the therapeutic effect. DBS is also a first choice option when motor complications such as dyskinesia emerge as a side effect of medication. Several studies have also reported that though DBS is found to be effective in suppressing severe motor symptoms such as tremors and rigidity, it has an adverse effect on cognitive capabilities. Henceforth, it is important to understand the exact mechanism of DBS in alleviating motor symptoms. A computational model of DBS stimulation for motor symptoms will offer great insights into understanding the mechanisms underlying DBS, and, along this line, in our current study, we modeled a cortico-basal ganglia circuitry of arm reaching, where we simulated healthy control (HC) and PD symptoms as well as the DBS effect on PD tremor and bradykinesia. Our modeling results reveal that PD tremors are more correlated with the theta band, while bradykinesia is more correlated with the beta band of the frequency spectrum of the local field potential (LFP) of the subthalamic nucleus (STN) neurons. With a DBS current of 220 pA, 130 Hz, and a 100 microsecond pulse-width, we could found the maximum therapeutic effect for the pathological dynamics simulated using our model using a set of parameter values. However, the exact DBS characteristics vary from patient to patient, and this can be further studied by exploring the model parameter space. This model can be extended to study different DBS targets and accommodate cognitive dynamics in the future to study the impact of DBS on cognitive symptoms and thereby optimize the parameters to produce optimal performance effects across modalities. Combining DBS with rehabilitation is another frontier where DBS can reduce symptoms such as tremors and rigidity, enabling patients to participate in their therapy. With DBS providing instant relief to patients, a combination of DBS and rehabilitation can enhance neural plasticity. One of the key motivations behind combining DBS with rehabilitation is to expect comparable results in motor performance even with milder DBS currents.