Motor Complications in Parkinson's Disease: Results from 3343 Patients Followed for up to 12 Years

BACKGROUND

Motor complications are well recognized in Parkinson's disease (PD), but their reported prevalence varies and functional impact has not been well studied.

OBJECTIVES

To quantify the presence, severity, impact and associated factors for motor complications in PD.

METHODS

Analysis of three large prospective cohort studies of recent-onset PD patients followed for up to 12 years. The MDS-UPDRS part 4 assessed motor complications and multivariable logistic regression tested for associations. Genetic risk score (GRS) for Parkinson's was calculated from 79 single nucleotide polymorphisms.

RESULTS

3343 cases were included (64.7% male). Off periods affected 35.0% (95% CI 33.0, 37.0) at 4-6 years and 59.0% (55.6, 62.3) at 8-10 years. Dyskinesia affected 18.5% (95% CI 16.9, 20.2) at 4-6 years and 42.1% (38.7, 45.5) at 8-10 years. Dystonia affected 13.4% (12.1, 14.9) at 4-6 years and 22.8% (20.1, 25.9) at 8-10 years. Off periods consistently caused greater functional impact than dyskinesia. Motor complications were more common among those with higher drug doses, younger age at diagnosis, female gender, and greater dopaminergic responsiveness (in challenge tests), with associations emerging 2-4 years post-diagnosis. Higher Parkinson's GRS was associated with early dyskinesia (0.026 ≤ P ≤ 0.050 from 2 to 6 years).

CONCLUSIONS

Off periods are more common and cause greater functional impairment than dyskinesia. We confirm previously reported associations between motor complications with several demographic and medication factors. Greater dopaminergic responsiveness and a higher genetic risk score are two novel and significant independent risk factors for the development of motor complications.

Reduced Plasma Levodopa Fluctuations with More Frequent Administration of a Novel Carbidopa/Levodopa Functionally Scored Tablet

Levodopa/carbidopa remains the gold standard for treating Parkinson disease (PD), but chronic pulsatile administration contributes to motor complications. This Phase 1 study used a new immediate-release (IR) formulation of carbidopa/levodopa 25/100 mg that is functionally scored for easy and precise splitting to evaluate the effects on levodopa plasma variability when smaller doses are taken more frequently. These functionally scored tablets were shown to be bioequivalent to carbidopa/levodopa 25-/100-mg IR generic reference tablets. Twenty-two healthy volunteers received a whole tablet every 4 hours versus half of the tablet every 2 hours. Plasma levodopa fluctuations were significantly reduced with half-tablets dosed every 2 hours, with a 44% reduction in peaks (P < .0001). While drug exposure did not differ, parameters that underlie motor response variations, including mean peak-to-trough difference and variance, were 51% and 56% less, respectively, with more frequent dosing (both P ≤ .0024). Safety and tolerability of both regimens were similar. In conclusion, more frequent administration of half-tablets of the new functionally scored IR formulation safely provided more constant levodopa levels than whole tablets dosed less often. This tablet technology could facilitate the benefits of more physiologic dopamine replenishment in patients with PD, particularly those with reduced manual dexterity.

Holter STAT-ON™ against other tools for detecting MF in advanced Parkinson's disease: an observational study

Background

Different screening tools to identify advanced Parkinson's disease (APD) have emerged in recent years. Among them, wearable medical devices, such as STAT-ON™, have been proposed to help to objectively detect APD.

Objectives

To analyze the correlation between STAT-ON™ reports and other assessment tools to identify APD and to assess the accuracy of screening tools in APD patients, using the STAT-ON™ as the gold standard.

Methods

In this retrospective, observational study, data from the University Hospital Complex of Pontevedra database on 44 patients with potential APD who wore STAT-ON™ were extracted. Data were collected according to different sources of tools for identifying APD: (1) STAT-ON™, (2) information provided by the patient, (3) questionnaire for advanced Parkinson's disease (CDEPA), (4) 5-2-1 Criteria, and (5) Making Informed Decisions to Aid Timely Management of Parkinson's Disease (MANAGE-PD). Considering STAT-ON™ recordings as a reference, the sensitivity, specificity, and positive and negative predictive values for each tool were calculated. The kappa index assessed the degree of agreement between the gold standard and the other instruments.

Results

Although no statistically significant association was found between STAT-ON™ recordings and any screening methods evaluated, the CDEPA questionnaire demonstrated the highest sensitivity and VPN values to detect patients with APD candidates for second-line therapy (SLT). According to the correlation analyses, MANAGE-PD demonstrated the highest degree of concordance with STAT-ON™ recordings to identify the SLT indication and to predict the SLT decision.

Conclusion

STAT-ON™ device may be a helpful tool to detect APD and to guide treatment decisions.

Identification and quantitative assessment of motor complications in Parkinson's disease using the Parkinson's KinetiGraph™

Introduction

Effective management and therapies for the motor complications of Parkinson's disease (PD) require appropriate clinical evaluation. The Parkinson's KinetiGraph™ (PKG) is a wearable biosensor system that can record the motion characteristics of PD objectively and remotely.

Objective

The study aims to investigate the value of PKG in identifying and quantitatively assessing motor complications including motor fluctuations and dyskinesia in the Chinese PD population, as well as the correlation with the clinical scale assessments.

Methods

Eighty-four subjects with PD were recruited and continuously wore the PKG for 7 days. Reports with 7-day output data were provided by the manufacturer, including the fluctuation scores (FS) and dyskinesia scores (DKS). Specialists in movement disorders used the Movement Disorder Society-Unified Parkinson's Disease Rating Scale-IV (MDS-UPDRS IV), the wearing-off questionnaire 9 (WOQ-9), and the unified dyskinesia rating scale (UDysRS) for the clinical assessment of motor complications. Spearman correlation analyses were used to evaluate the correlation between the FS and DKS recorded by the PKG and the clinical scale assessment results. Receiver operating characteristic (ROC) curves were generated to analyze the sensitivity and specificity of the FS and DKS scores in the identification of PD motor complications.

Results

The FS was significantly positively correlated with the MDS-UPDRS IV motor fluctuation (items 4.3-4.5) scores (r = 0.645, p < 0.001). ROC curve analysis showed a maximum FS cut-off value of 7.5 to identify motor fluctuation, with a sensitivity of 74.3% and specificity of 87.8%. The DKS was significantly positively correlated with the UDysRS total score (r = 0.629, p < 0.001) and the UDysRS III score (r = 0.634, p < 0.001). ROC curve analysis showed that the maximum DKS cut-off value for the diagnosis of dyskinesia was 0.7, with a sensitivity of 83.3% and a specificity of 83.3%.

Conclusion

The PKG assessment of motor complications in the PD population analyzed in this study has a significant correlation with the clinical scale assessment, high sensitivity, and high specificity. Compared with clinical evaluations, PKG can objectively, quantitatively, and remotely identify and assess motor complications in PD, providing a good objective recording for managing motor complications.

Levodopa-Induced Dyskinesias in Parkinson's Disease: An Overview on Pathophysiology, Clinical Manifestations, Therapy Management Strategies and Future Directions

Since its first introduction, levodopa has become the cornerstone for the treatment of Parkinson's disease and remains the leading therapeutic choice for motor control therapy so far. Unfortunately, the subsequent appearance of abnormal involuntary movements, known as dyskinesias, is a frequent drawback. Despite the deep knowledge of this complication, in terms of clinical phenomenology and the temporal relationship during a levodopa regimen, less is clear about the pathophysiological mechanisms underpinning it. As the disease progresses, specific oscillatory activities of both motor cortical and basal ganglia neurons and variation in levodopa metabolism, in terms of the dopamine receptor stimulation pattern and turnover rate, underlie dyskinesia onset. This review aims to provide a global overview on levodopa-induced dyskinesias, focusing on pathophysiology, clinical manifestations, therapy management strategies and future directions.

A meta-analysis of the effectiveness and safety of safinamide for levodopa-induced motor complications in Parkinson's disease

To systematically evaluate the effectiveness and safety of safinamide in the treatment of levodopa-induced motor complications of Parkinson's disease (PD). A search strategy was developed and PubMed, Embase, Web of Science, Cochrane Library, Chinese BioMedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), and WanFang Data were searched to find randomized controlled trials on the treatment of PD motor complications caused by levodopa with safinamide. A manual reference search was conducted for articles published until June 2022 to independently screen references, extract data, and evaluate the risk of bias in the included studies. RevMan 5.3 software was utilized to analyze the data. A total of 5 randomized controlled trials with 2061 PD patients were included, containing 1277 patients in the safinamide group (trial group) and 784 patients in the control group. Meta-analysis results exhibited that regarding effectiveness, the duration of continuous optimal drug effect without dyskinesia (On-time) of the 50 mg trial group was longer than that of the control group. The On-time of the 100 mg trial group was longer than that of the control group.The improvement of the Unified Parkinson's Disease Rating Scale Part III (UPDRSIII) score in the 50 mg trial group was better than that in the control group. The improvement of the UPDRSIII score of the 100 mg trial group was better than that of the control group.There was no significant difference in the incidence of adverse events between the two groups. Safinamide is effective and safe in the treatment of PD motor complications caused by levodopa.

Effective Management of "OFF" Episodes in Parkinson's Disease: Emerging Treatment Strategies and Unmet Clinical Needs

Motor complications related to the chronic administration of levodopa and failure to prevent the neurodegenerative disease process counterbalance the pivotal discovery of levodopa as the cornerstone of PD treatment. Excellent motor control is offered early during the course of treatment, but this diminishes as pathological changes in the striatum lead to synaptic dopamine levels becoming completely dependent on exogenous dopamine. This non-physiologic stimulation of dopamine receptors eventually manifests as OFF episodes. As no disease modifying therapy exists for PD that can disrupt these pathological changes, most research and treatment focuses on optimization of dopaminergic stimulation of striatal receptors so that they mimic tonic, physiologic stimulation as closely as possible. Strategies focusing on these challenges have included non-pharmacologic approaches, optimizing levodopa pharmacokinetics, using adjunctive treatments including those with non-dopaminergic mechanisms, and implementing rescue therapies. Device aided therapies, including surgery, are also available. In this review, we will focus on effective management of motor symptoms related to OFF periods, including emerging strategies. Unmet clinical needs will be discussed, including non-motor symptoms, targeted molecular therapies and disease modifying therapy.

Initiating dopamine agonists rather than levodopa in early Parkinson's disease does not delay the need for deep brain stimulation

BACKGROUND

While levodopa is the most effective symptomatic treatment for Parkinson's disease (PD), its use is associated with an increased risk of motor complications (MC) in the first five years of treatment compared to dopamine agonist (DA) first therapy. It is not known whether this translates into true benefit later in the disease. We aimed to determine whether there is a difference in the time between initial levodopa vs DA treatment and the development of disabling MC prompting DBS consideration.

METHODS

This was a retrospective cohort study of PD patients attending the DBS Clinic at Toronto Western Hospital, Canada between 03/2004-02/2022 who underwent globus pallidus interna (GPi) or subthalamic nucleus (STN) DBS in 2005 or later for disabling MC.

RESULTS

Of 438 patients included, 352 patients underwent STN DBS, 86 GPi. The median disease duration was 9 years (2-30). The majority (n=312) received levodopa first and 126 a DA. There was no significant difference in the disease duration, or amantadine use between the two groups. The duration first treatment-assessment for DBS (L-dopa median 8, IQR 4; DA median 9, IQR 4) or DBS surgery (levodopa median 10, IQR 5; DA median 10, IQR 5), did not differ.

CONCLUSION

To our knowledge this is the only study to date to evaluate the duration between L-dopa/DA first treatment and the development of MC of sufficient severity to warrant consideration of DBS. No association was found. The results suggest that the development of disabling MC warranting DBS is independent of the type of first dopaminergic treatment.

Long-term efficacy of bilateral subthalamic deep brain stimulation in the parkinsonism of SCA 3: A rare case report

BACKGROUND AND PURPOSE

Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant inherited disorder that manifests as a mixture of cerebellar ataxia, parkinsonism, and polyneuropathy; in type IV SCA3, pure parkinsonism is the only symptom. Currently, no disease-modifying treatment is available, but variable responses to antiparkinsonism agents have been reported. However, the benefits of deep brain stimulation (DBS) for treating parkinsonism in this subtype of SCA3 remain unclear.

METHODS

A 39-year-old male patient with a rare disorder of type IV SCA3 presented with pure parkinsonism including unilateral resting tremor, rigidity, and bradykinesia at the age of 30 years. Young-onset Parkinson disease was diagnosed at the age of 32 years. His family history revealed a mild ataxia in his father since the age of 55 years. Genetic testing confirmed an expanded CAG repeated number, with 66 in this case and 63 in his father for SCA3 mutation. Excellent response to levodopa and dopamine agonists in the first 3 years was noted, but wearing-off phenomena, levodopa-induced dyskinesia, and severe impulse control disorders later developed. To alleviate drug-induced complications, he received bilateral subthalamic nucleus deep brain stimulation (STN-DBS) in the absence of cerebellar signs, depression, and cognitive impairment.

RESULTS

As of 2019, no impulsive control disorders, motor fluctuations, or DBS-related complications were observed during a 4-year follow-up, with 66% Unified Parkinson's Disease Rating Scale Part III reduction at medication OFF state noted, whereas levodopa equivalent daily dosage decreased by almost half.

CONCLUSIONS

STN-DBS may be considered as adjunct treatment for severe dopa-related motor/nonmotor complications in patients with parkinsonian phenotype of SCA 3.

The Influence of ADORA2A on Levodopa-Induced Dyskinesia

BACKGROUND

Dopamine deficiency causes Parkinson's disease (PD), and on treatment, levodopa is the gold standard. Various drug-metabolizing enzymes and drug receptors are believed to be involved in prompting dyskinesias due to the extended usage of levodopa. Shreds of evidence in genomic studies have presented that ADORA2A receptor antagonism has beneficial outcomes to avoid these drug-induced side effects.

OBJECTIVE

The aim of this study was to study the polymorphisms of rs2298383, rs35060421, and rs5751876 in the ADORA2A in patients diagnosed as PD and describe their possible relationships with levodopa-induced dyskinesias (LID).

METHODS

One-hundred and seventy-two patients were recruited and separated as the study and the control group. DNA was achieved from peripheral venous blood, high resolution melting analysis, and reverse-transcriptase PCR was performed.

RESULTS

The allele differences among the groups were not statistically significant. Although it was not statistically significant, the rs35060421 allele was observed to repeat more frequently. However, we did not find an association between such polymorphisms of ADORA2A and LID.

CONCLUSIONS

Although this result showed that a higher sample number might produce different results as possible, current results in the Turkish sample indicated that these alleles of ADORA2A might not be related to LID in patients.

GOCOVRI® (amantadine) extended-release capsules in Parkinson's disease

Amantadine is an old, antiviral compound, which moderately improves motor behavior in Parkinson's disease. Its current resurgence results from an innovative, delayed uptake and extended release amantadine hydrochloride capsule, given at bedtime once daily. It is the only approved compound for reduction of involuntary movements, so called dyskinesia, in fluctuating orally levodopa treated patients. It additionally ameliorates 'off'-intervals characterized by impaired motor behavior. These beneficial effects result from higher and more continuous brain delivery of amantadine. Future clinical research is warranted on preventive effects of this amantadine capsule combined with enzyme blockers of central monoamine oxidase B and peripheral catechol-O-methyltransferase on motor complications in orally levodopa treated patients, as all these pharmacological principles support the concept of continuous dopamine substitution.

Pharmacokinetics of Levodopa and 3-O-Methyldopa in Parkinsonian Patients Treated with Levodopa and Ropinirole and in Patients with Motor Complications

Parkinson’s disease (PD) is a progressive, neurodegenerative disorder primarily affecting dopaminergic neuronal systems, with impaired motor function as a consequence. The most effective treatment for PD remains the administration of oral levodopa (LD). Long-term LD treatment is frequently associated with motor fluctuations and dyskinesias, which exert a serious impact on a patient’s quality of life. The aim of our study was to determine the pharmacokinetics of LD: used as monotherapy or in combination with ropinirole, in patients with advanced PD. Furthermore, an effect of ropinirole on the pharmacokinetics of 3-OMD (a major LD metabolite) was assessed. We also investigated the correlation between the pharmacokinetic parameters of LD and 3-OMD and the occurrence of motor complications. Twenty-seven patients with idiopathic PD participated in the study. Thirteen patients received both LD and ropinirole, and fourteen administered LD monotherapy. Among 27 patients, twelve experienced fluctuations and/or dyskinesias, whereas fifteen were free of motor complications. Inter- and intra-individual variation in the LD and 3-OMD concentrations were observed. There were no significant differences in the LD and 3-OMD concentrations between the patients treated with a combined therapy of LD and ropinirole, and LD monotherapy. There were no significant differences in the LD concentrations in patients with and without motor complications; however, plasma 3-OMD levels were significantly higher in patients with motor complications. A linear one-compartment pharmacokinetic model with the first-order absorption was adopted for LD and 3-OMD. Only mean exit (residence) time for 3-OMD was significantly shorter in patients treated with ropinirole. Lag time, V/F, CL/F and t_max of LD had significantly lower values in patients with motor complications. On the other hand, AUC were significantly higher in these patients, both for LD and 3-OMD. 3-OMD C_max was significantly higher in patients with motor complications as well. Our results showed that ropinirole does not influence LD or 3-OMD concentrations. Higher 3-OMD levels play a role in inducing motor complications during long-term levodopa therapy.

Lack of Association Between GBA Mutations and Motor Complications in European and American Parkinson's Disease Cohorts

Background:

Motor complications are a consequence of the chronic dopaminergic treatment of Parkinson’s disease (PD) and include levodopa-induced dyskinesia (LIDs) and motor fluctuations (MF). Currently, evidence is on lacking whether patients with GBA-associated PD differ in their risk of developing motor complications compared to the general PD population.

Objective:

To evaluate the association of GBA carrier status with the development of LIDS and MFs from early PD.

Methods:

Motor complications were recorded prospectively in 884 patients with PD from four longitudinal cohorts using part IV of the UPDRS or MDS-UPDRS. Subjects were followed for up to 11 years and the associations of GBA mutations with the development of motor complications were assessed using parametric accelerated failure time models.

Results:

In 439 patients from Europe, GBA mutations were detected in 53 (12.1%) patients and a total of 168 cases of LIDs and 258 cases of MF were observed. GBA carrier status was not associated with the time to develop LIDs (HR 0.78, 95%CI 0.47 to 1.26, p = 0.30) or MF (HR 1.19, 95%CI 0.84 to 1.70, p = 0.33). In the American cohorts, GBA mutations were detected in 36 (8.1%) patients and GBA carrier status was also not associated with the progression to LIDs (HR 1.08, 95%CI 0.55 to 2.14, p = 0.82) or MF (HR 1.22, 95%CI 0.74 to 2.04, p = 0.43).

Conclusion:

This study does not provide evidence that GBA-carrier status is associated with a higher risk of developing motor complications. Publication of studies with null results is vital to develop an accurate summary of the clinical features that impact patients with GBA-associated PD.

Management Challenges of Severe, Complex Dyskinesia. Data from a Large Cohort of Patients Treated with Levodopa-Carbidopa Intestinal Gel for Advanced Parkinson's Disease

BACKGROUND

In the advanced stages of Parkinson's disease (APD), complex forms of dyskinesia may severely impair the patient's quality of life.

OBJECTIVE

In the present study, we aimed to analyze the evolution under LCIG therapy of the most important motor fluctuations and complex disabling dyskinesias, including diphasic dyskinesia.

METHODS

In this retrospective study, we analyzed the characteristics of patients with APD who had at least 30 min of diphasic dyskinesia (DID) in 3 consecutive days, were considered responders and were treated with LCIG in our clinic. Patients were evaluated before and after PEG and at 6, 12 and 18 months, when the changes in the therapy were recorded, and they completed a 7-point Global Patient Impression of Improvement (PGI-I) scale.

RESULTS

Forty patients fulfilled the inclusion criteria-out of which, 34 performed all visits. There was a substantial difference between the calculated and real LCIG (1232 ± 337 mg vs. 1823 ± 728 mg). The motor fluctuations and most dyskinesias improved significantly after starting LCIG, but an increasing number of patients needed longer daily administrations of LCIG (24 instead of 16 h).

CONCLUSIONS

Patients with APD with complex dyskinesias must be tested in dedicated hospitals, and they need a special therapeutic approach. The properly adapted LCIG treatment regarding the dose and time of administration completed with well-selected add-on medication should offer improvement for patients who want to or can only choose this DAT vs. others.

Decision-making and duration to accept device-aided therapy in advanced Parkinson’s disease

Összefoglaló. Bevezetés: Az előrehaladott Parkinson-kór bizonyos fázisában a motoros komplikációk már nem befolyásolhatók hatékonyan a hagyományos orális, illetve transdermalis gyógyszerekkel. Ilyenkor meg kell fontolni, komplex felmérési és döntési folyamatot követően, az invazív eszközös terápiák bevezetését. Célkitűzés: A döntéshozatal és a fontosabb klinikai paraméterek elemzése levodopa-karbidopa intestinalis géllel kezelt betegeinknél az elfogadás időtartamának függvényében. Módszer: Retrospektíven vizsgáltuk azon betegeink adatait, akiknél a marosvásárhelyi 2. Sz. Ideggyógyászati Klinikán 2011. június 1. és 2019. december 31. között vezettük be a levodopa-karbidopa intestinalis géllel történő terápiát. A kezelés elfogadásához szükséges időintervallum szerint két csoportot alkottunk: egy hónap vagy annál rövidebb, illetve egy hónapnál több idő az első, célzott kivizsgálás és a tesztelés megkezdése között. Eredmények: A vizsgált időszakban 163 betegnél teszteltük orrszondán a kezelés hatékonyságát, közülük 127 esetben történt meg a terápia véglegesítése. A döntéshozatal 56 betegnél egy hónap vagy annál rövidebb időt, míg 71 betegnél egy hónapnál több időt igényelt. A dyskinesisek átlagos időtartamának szempontjából szignifikáns különbséget találtunk a két csoport között (3,1 ± 0,7 vs. 2,8 ± 0,8 óra, p = 0,02). Az eszközös terápia bevezetése előtti levodopa-átlagadag 821,5 ± 246,6 mg volt, naponta átlagosan 5-ször adagolva. A kiegészítő terápiák alkalmazási arányai: a dopaminagonisták 80,3%-ban, a katechol-O-metiltranszferáz-gátlók 62,2%-ban, illetve a monoaminoxidáz-B-gátlók 68,5%-ban. Az átlagos off időtartam 4,7 ± 1,1 óra volt, és 85 betegünknél tapasztaltunk 2,9 ± 0,8 óra átlag-időtartamú dyskinesist. Következtetés: Hamarabb fogadják el az eszközös terápiát azok az előrehaladott Parkinson-kóros betegek, akiknek hosszabb időtartamú a napi dyskinesisük, illetve régebbi a betegségük. A terápiás irányelvek gyakorlatba ültetésekor figyelembe kell venni a helyi sajátosságokat: a kiegészítő gyógyszerekhez, illetve az eszközös terápiákhoz való hozzáférést. Orv Hetil. 2021; 162(21): 839-847.

SUMMARY

INTRODUCTION

In advanced stages of Parkinson's disease, motor complications cannot be effectively controlled with conventional therapies. In such cases, the complex assessment and decision-making process that leads to device-aided therapies should be considered.

OBJECTIVE

To analyze the decision-making and key clinical parameters, as a function of duration of acceptance, patients treated with levodopa-carbidopa intestinal gel.

METHOD

We retrospectively examined the data of patients who started levodopa-carbidopa intestinal gel therapy at the 2nd Department of Neurology Târgu Mureş, between 1 June 2011 and 31 December 2019. Two groups were formed: less than one month and more than one month between the first targeted examination and the start of testing.

RESULTS

Therapeutic efficiency was tested with nasal tube on 163 patients, out of whom 127 patients remained on treatment. Decision-making took one month or less for 56 patients and more than a month for 71 patients. Duration of dyskinesias was significantly different between the two groups (3.1 ± 0.7 vs 2.8 ± 0.8 hours, p = 0.02). Mean dose of levodopa prior to the introduction of device-aided therapy was 821.5 ± 246.6 mg, administered 5 times daily. Dopamine agonists were used in 80.3%, catechol-O-methyltransferase inhibitors in 62.2%, and monoamine oxidase-B inhibitors in 68.5% of cases. The mean off-time was 4.7±1.1 hours and data from 85 patients showed 2.9 ± 0.8 hours of dyskinesia.

CONCLUSION

Device-aided therapy is adopted sooner by patients with advanced Parkinson's disease with longer disease duration and more dyskinesias. Local specificities, such as access to add-on medication and device-aided therapies, must be taken into account when implementing therapeutic guidelines. Orv Hetil. 2021; 162(21): 839-847.

Expression of Transcription Factors in CD4 + T Cells as Potential Biomarkers of Motor Complications in Parkinson's Disease

Background:

Management of motor complications (MC) represents a major challenge in the long-term treatment of Parkinson’s disease (PD) patients. In this context, the role of peripheral adaptive immunity may provide new insights, since neuroinflammatory mechanisms have been proved crucial in the disease.

Objective:

The aim of this study was to analyze the transcription factors genes involved in CD4 + T cells development to uncover specific molecular signatures in patients with (PMC) and without (WMC) motor complications.

Methods:

mRNA levels of CD4 + T lymphocytes transcription factor genes TBX21, STAT1, STAT3, STAT4, STAT6, RORC, GATA3, FOXP3, and NR4A2 were measured from 40 PD patients, divided into two groups according to motor complications. Also, 40 age- and sex-matched healthy controls were enrolled.

Results:

WMC patients had higher levels of STAT1 and NR4A2 (p = 0.004; p = 0.003), whereas in PMC we found higher levels of STAT6 (p = 0.04). Also, a ROC curve analysis confirmed STAT1 and NR4A2 as feasible biomarkers to discriminate WMC (AUC = 0.76, 95%CI 0.59–0.92, p = 0.005; AUC = 0.75, 95%CI 0.58–0.90, p = 0.007). Similarly, STAT6 detected PMC patients (AUC = 0.69, 95%CI 0.52–0.86, p = 0.037).

Conclusion:

These results provide evidence of different molecular signatures in CD 4 + T cells of PD patients with and without MC, thus suggesting their potential as biomarkers of MC development.

Evaluation of the Direct Effect of Bilateral Deep Brain Stimulation of the Subthalamic Nucleus on Levodopa-Induced On-Dyskinesia in Parkinson's Disease

Objective: This study aimed to evaluate the direct anti-dyskinesia effect of deep brain stimulation (DBS) of subthalamic nucleus (STN) on levodopa-induced on-dyskinesia in Parkinson's disease (PD) patients during the early period after surgery without reducing the levodopa dosage.

Methods: We retrospectively reviewed PD patients who underwent STN-DBS from January 2017 to October 2019 and enrolled patients with levodopa-induced on-dyskinesia before surgery and without a history of thalamotomy or pallidotomy. The Unified Dyskinesia Rating Scale (UDysRS) parts I+III+IV and the Unified Parkinson's Disease Rating Scale part III (UPDRS-III) were monitored prior to surgery, and at the 3-month follow-up, the location of active contacts was calculated by postoperative CT–MRI image fusion to identify stimulation sites with good anti-dyskinesia effect.

Results: There were 41 patients enrolled. The postoperative levodopa equivalent daily dose (LEDD) (823.1 ± 201.5 mg/day) was not significantly changed from baseline (844.6 ± 266.1 mg/day, P = 0.348), while the UDysRS on-dyskinesia subscores significantly decreased from 24 (10–58) to 0 (0–18) [median (range)] after STN stimulation (P < 0.0001). The levodopa-induced on-dyskinesia recurred in stimulation-off/medication-on state in all the 41 patients and disappeared in 39 patients when DBS stimulation was switched on at 3 months of follow-up. The active contacts which correspond to good effect for dyskinesia were located above the STN, and the mean coordinate was 13.05 ± 1.24 mm lateral, −0.13 ± 1.16 mm posterior, and 0.72 ± 0.78 mm superior to the midcommissural point.

Conclusions: High-frequency electrical stimulation of the area above the STN can directly suppress levodopa-induced on-dyskinesia.

Amantadine ER (Gocovri®) Significantly Increases ON Time Without Any Dyskinesia: Pooled Analyses From Pivotal Trials in Parkinson's Disease

Background: Clinical trials for antiparkinsonian drugs aimed at managing motor complications typically use patient diaries to divide levodopa-induced dyskinesias (LID) into "troublesome" and "non-troublesome" categories. Yet, given the choice, most patients would prefer to live without experiencing any dyskinesia. However, the concept of evaluating time spent ON without any dyskinesia as an outcome has never been tested. We conducted analyses of pooled Gocovri pivotal trial data in order to evaluate the extent to which Gocovri increased the time PD patients spent ON without dyskinesia (troublesome or non-troublesome), beyond its already identified improvement in reducing troublesome dyskinesia. Methods: Patients enrolled in phase 3 trials (EASE LID [NCT02136914] or EASE LID 3 [NCT02274766]) recorded time spent in the following PD diary states at baseline and Week 12 (endpoint): asleep, OFF, ON with troublesome dyskinesia, ON with non-troublesome dyskinesia, and ON without dyskinesia. Mixed model repeated measures analyses with estimated Cohen D effect sizes were performed on the modified intent to treat population to evaluate changes in time spent in these states. Results: Patients randomized to receive Gocovri showed an increase in ON time without dyskinesia and corresponding decreases in ON time with dyskinesia and OFF time vs. placebo. Treatment effects were statistically significant for Gocovri vs. placebo starting at Week 2 and were sustained until Week 12. On MMRM analysis at Week 12, patients in the Gocovri group showed an adjusted mean ± SE increase over placebo of 2.9 ± 0.6 h in ON time without dyskinesia (Cohen D effect size 0.79) and an adjusted mean ± SE decrease of -1.9 ± 0.6 h in ON time with dyskinesia (troublesome + non-troublesome) (Cohen D effect size 0.49), that included a -1.5 ± 0.4 h placebo-adjusted reduction in ON time with troublesome dyskinesia and a -0.6 ± 0.4 h reduction in ON time with non-troublesome dyskinesia. OFF time was reduced by -1.0 ± 0.3 h compared to placebo. Conclusions: Gocovri treatment more than doubled the daily time patients spent ON without dyskinesia. These results suggest that the Gocovri treatment effect was driven by a reduction in overall motor complications including ON time with both troublesome and non-troublesome dyskinesia as well as time spent OFF.

Potential protective role of ACE-inhibitors and AT1 receptor blockers against levodopa-induced dyskinesias: a retrospective case-control study

Growing evidence has highlighted that angiotensin-converting enzyme (ACE)-inhibitors (ACEi)/AT1 receptor blockers (ARBs) may influence the complex interplay between dopamine and the renin-angiotensin system in the nigrostriatal pathway, thus affecting the development of levodopa-induced dyskinesia in Parkinson's disease (PD). In the present study, we analyzed whether the use of this class of medication was associated with a reduced occurrence of levodopa-induced dyskinesia, using electronically-stored information of idiopathic PD patients enrolled at Novara University Hospital “Maggiore della Carità". We conducted a retrospective case-control study identifying PD patients with dyskinesias (PwD; n = 47) as cases. For each PwD we selected a non-dyskinetic control (NoD), nearly perfectly matched according to sex, Unified Parkinson's Disease Rating Scale (UPDRS) part III score, and duration of antiparkinsonian treatment. Binary logistic regression was used to evaluate whether dyskinesias were associated with ACEi/ARBs use. Ninety-four PD patients were included, aged 72.18 ± 9 years, with an average disease duration of 10.20 ± 4.8 years and 9.04 ± 4.9 years of antiparkinsonian treatment. The mean UPDRS part III score was 18.87 ± 7.6 and the median HY stage was 2. In the NoD group, 25 (53.2%) were users and 22 (46.8%) non-users of ACEi/ARBs. Conversely, in the PwD group, 11 (23.4%) were users and 36 non-users (76.6%) of this drug class (Pearson chi-square = 8.824, P = 0.003). Concerning general medication, there were no other statistically significant differences between groups. After controlling for tremor dominant phenotype, levodopa equivalent daily dose, HY 3-4, and disease duration, ACEi/ARBs use was a significant predictor of a lower occurrence of dyskinesia (OR = 0.226, 95% CI: 0.080–0.636, P = 0.005). Therefore, our study suggests that ACEi/ARBs may reduce levodopa-induced dyskinesia occurrence and, thanks to good tolerability and easy management, represent a feasible choice when dealing with the treatment of hypertension in PD patients. The study was approved by the Ethics Committee of Novara University Hospital “Maggiore della Carità” (CE 65/16) on July 27, 2016.

An evaluation of subcutaneous apomorphine for the treatment of Parkinson's disease

INTRODUCTION

Heterogeneity of symptoms and individual variability of progression characterizes Parkinson's disease. Unmet therapeutic needs include a cure, disease modification, and improvement of available marketed dopamine-substituting compounds. Personalized treatment, tailored to the patients' needs and symptoms, aims to ameliorate impaired motor behavior and non-motor features. Injection or infusion of apomorphine is a therapeutic option for more advanced patients with severe levodopa associated motor complications.

AREAS COVERED

This narrative review summarizes the subcutaneous administration, efficacy, and side effects of the non-ergot derivative dopamine agonist apomorphine following a non-systematic literature research.

EXPERT OPINION

Subcutaneous apomorphine hydrochloride application rapidly terminates intervals with severe motor impairment with bolus injections. Oscillation of motor behavior well responds to continuous apomorphine infusions. Long-term application of the commercially available apomorphine hydrochloride solution sooner or later affects skin and oral mucosa. Onset of skin nodules associated with subcutaneous tissue inflammation probably results from the antioxidant preservative sodium metabisulfite in the apomorphine solution. Addition of another better tolerated and safer antioxidant instead of sodium metabisulphite or use of an already available concentrated apomorphine-free base formulation will enhance its future use, its tolerability, safety, and acceptance of subcutaneous and sublingual application.

Parkinson's Disease Multimodal Complex Treatment (PD-MCT): Analysis of Therapeutic Effects and Predictors for Improvement

Parkinson’s disease Multimodal Complex Treatment (PD-MCT) is a multidisciplinary inpatient treatment approach that has been demonstrated to improve motor function and quality of life in patients with Parkinson’s disease (PD). In this study, we assessed the efficacy of PD-MCT and calculated predictors for improvement. We performed a prospective analysis in a non-randomized, open-label observational patient cohort. Study examinations were done at baseline (BL), at discharge after two-weeks of inpatient treatment (DC) and at a six-week follow-up examination (FU). Besides Movement Disorders Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) III as a primary outcome, motor performance was measured by the Timed Up-and-Go (TUG), the Berg Balance Scale (BBS) and the Perdue Pegboard Test (PPT). Until DC, motor performance improved significantly in several parameters and was largely maintained until FU (MDS-UPDRS III BL-to-DC: −4.7 ± 1.2 (SE) p = 0.0012, BL-to-FU: −6.1 ± 1.3 p = 0.0001; TUG BL-to-DC: −2.5 ± 0.9 p = 0.015, BL-to-FU: 2.4 ± 0.9 p = 0.027; BBS BL-to-DC: 2.4 ± 0.7 p = 0.003, BL-to-FU: 1.3 ± 0.7 p = 0.176, PPT BL-to-DC: 3.0 ± 0.5 p = 0.000004, BL-to-FU: 1.7 ± 0.7 p = 0.059). Overall, nontremor items were more therapy responsive than tremor items. Motor complications evaluated with MDS-UPDRS IV occurred significantly less frequent at DC (−1.8 ± 0.5 p = 0.002). Predictor analyses revealed an influence of initial motor impairment and disease severity on the treatment response in different motor aspects. In summary, we demonstrate a significant positive treatment effect of PD-MCT on motor function of PD patients which can be maintained in several parameters for an extended time period of six weeks and identify predictors for an improvement of motor function.

Establishing apomorphine treatment in Thailand: understanding the challenges and opportunities of Parkinson's disease management in developing countries

INTRODUCTION

The increasing global burden of Parkinson's disease (PD) poses a particular challenge for developing countries, such as Thailand, when delivering care to a geographically diverse populace with limited resources, often compounded by a lack of expertise in the use of certain PD medications, such as device-aided therapies (DAT).

AREAS COVERED

A panel of local, regional, and international PD experts convened to review the unmet needs of PD in Thailand and share insights into effective delivery of DAT, focusing on experience with apomorphine infusion. Despite its proven efficacy and safety, implementation of apomorphine infusion as a new option was not straightforward. This has prompted a range of health-care professional and patient-focused initiatives, led by the Chulalongkorn Center of Excellence for Parkinson's Disease and Related Disorders in Bangkok, to help establish a more coordinated approach to PD management throughout the country and ensure patients have access to suitable treatments.

EXPERT OPINION

Overcoming the challenges of education, proficiency, resource capacity and standard of care for PD patients in developing countries requires a coordinated effort both nationally and beyond. The best practices identified in Thailand following the introduction of apomorphine infusion might be helpful for other countries when implementing similar programs.

MRI of Motor and Nonmotor Therapy-Induced Complications in Parkinson's Disease

Levodopa therapy remains the most effective drug for the treatment of Parkinson's disease, and it is associated with the greatest improvement in motor function as assessed by the Unified Parkinson's Disease Rating Scale. Dopamine agonists have also proven their efficacy as monotherapy in early Parkinson's disease but also as adjunct therapy. However, the chronic use of dopaminergic therapy is associated with disabling motor and nonmotor side effects and complications, among which levodopa-induced dyskinesias and impulse control behaviors are the most common. The underlying mechanisms of these disorders are not fully understood. In the last decade, classic neuroimaging methods and more sophisticated techniques, such as analysis of gray-matter structural imaging and functional magnetic resonance imaging, have given access to anatomical and functional abnormalities, respectively, in the brain. This review presents an overview of structural and functional brain changes associated with motor and nonmotor therapy-induced complications in Parkinson's disease. Magnetic resonance imaging may offer structural and/or functional neuroimaging biomarkers that could be used as predictive signs of development, maintenance, and progression of these complications. Neurophysiological tools, such as theta burst stimulation and transcranial magnetic stimulation, might help us to integrate neuroimaging findings and clinical features and could be used as therapeutic options, translating neuroimaging data into clinical practice. © 2020 International Parkinson and Movement Disorder Society.

Dopamine Transporter, Age, and Motor Complications in Parkinson's Disease: A Clinical and Single-Photon Emission Computed Tomography Study

BACKGROUND

Previous molecular imaging studies comparing dopamine function in vivo between early-onset PD and late-onset PD patients have shown contradictory results, presumably attributable to the aging-related decline in nigrostriatal function.

OBJECTIVES

(1) To investigate baseline dopamine transporter availability in early-onset PD (<55 years) and late-onset PD (>70 years) patients, z-scores values of putamen and caudate [¹²³ I]-ioflupane uptake were calculated using the respective age-matched controls in order to correct for early presynaptic compensatory mechanisms and age-related dopamine neuron loss; (2) to examine the associations of such baseline single-photon emission computed tomography measures with the emergence of late-disease motor complications.

METHODS

In this retrospective study, 105 de novo PD patients who underwent [¹²³ I]-ioflupane single-photon emission computed tomography at time of diagnosis were divided into three tertile groups according to age at disease onset (35 early-onset PD and 40 late-onset PD patients). Z-scores were compared between the two groups, and their predictive power for motor complications (during a mean follow-up of 7 years) was evaluated using Cox proportional hazard models.

RESULTS

Despite a less-severe motor phenotype, early-onset PD patients exhibited more reduced [¹²³ I]-ioflupane binding in the putamen and had a higher and earlier risk for developing motor complications than those with late-onset PD. Lower [¹²³ I]-Ioflupane uptake in the putamen and caudate increased the risk of motor complications.

CONCLUSIONS

Our findings indicate that a lower dopamine transporter binding in early-onset PD predicts the later development of motor complications, but it is not related to severity of motor symptoms, suggesting age-related differences in striatal compensatory mechanisms in PD. © 2020 International Parkinson and Movement Disorder Society.

Motor complications in Parkinson's disease: 13-year follow-up of the CamPaIGN cohort

BACKGROUND

Long-term population-representative data on motor fluctuations and levodopa-induced dyskinesias in Parkinson's disease is lacking.

METHODS

The Cambridgeshire Parkinson's Incidence from GP to Neurologist (CamPaIGN) cohort comprises incident PD cases followed for up to 13 years (n = 141). Cumulative incidence of motor fluctuations and levodopa-induced dyskinesias and risk factors were assessed using Kaplan-Meyer and Cox regression analyses.

RESULTS

Cumulative incidence of motor fluctuations and levodopa-induced dyskinesias was 54.3% and 14.5%, respectively, at 5 years and 100% and 55.7%, respectively, at 10 years. Higher baseline UPDRS-total and SNCA rs356219(A) predicted motor fluctuations, whereas higher baseline Mini-mental State Examination and GBA mutations predicted levodopa-induced dyskinesias. Early levodopa use did not predict motor complications. Both early motor fluctuations and levodopa-induced dyskinesias predicted reduced mortality in older patients (age at diagnosis >70 years).

CONCLUSIONS

Our data support the hypothesis that motor complications are related to the severity of nigrostriatal pathology rather than early levodopa use and indicate that early motor complications do not necessarily confer a negative prognosis. © 2019 International Parkinson and Movement Disorder Society.

Levodopa Effect and Motor Function in Late Stage Parkinson's Disease

BACKGROUND

It is unclear to which degree Levodopa (L-dopa) remains effective also in the late stage of Parkinson's disease (PD) and to which degree motor fluctuations and dyskinesias remain a problem.

OBJECTIVE

To assess responsiveness of motor symptomatology to L-dopa in a group of patients with late stage PD. Moreover, to investigate the extent to which motor fluctuations and dyskinesias occur.

METHODS

Thirty PD patients in Hoehn and Yahr (HY) stages IV and V in "on" were included. L-dopa responsiveness was assessed with a standardized L-dopa test in the defined "off" and defined "on" states. Motor function was assessed by the Unified PD Rating Scale (UPDRS) III and timed tests. Motor fluctuations and dyskinesias were assessed by the UPDRS IV. The participants were further monitored for 10 days with a mobile movement-analyses-system, the Parkinson's Kinetigraph (PKG). The median (q1-q3) L-dopa equivalent daily dose (LEDD) was 799 (536-973) mg.

RESULTS

The UPDRS III score improved with ≥15% in 15 (50%) and with ≥30% in six (20%) participants during the L-dopa test. The median (q1-q3) UPDRS III score in "off" was 46 (37-53) and in "on" 36 (28-46). Twenty-one (70%) of the participants reported either predictable or unpredictable "off" fluctuations (items 36-37). The prevalence of dyskinesias (item 32, duration of dyskinesias ≥1) was 47%. The PKG indicated that dyskinesias primarily were mild and that a majority had a pronounced "off" symptomatology, spending a large proportion of the day either asleep or very inactive.

CONCLUSIONS

Half of a group of patients with late stage PD had an L-dopa response of ≥15% on the UPDRS III. According to the UPDRS IV, a majority of the patients had motor fluctuations and about half had dyskinesias, although the PKG results suggested that these were not very severe.

[Characteristics of levodopa treatment in advanced Parkinson's disease in the experiences of the neurology clinics of Târgu Mureș, Romania]

Introduction: The motor and non-motor complications of Parkinson's disease impair the patients' quality of life and limit therapeutical options. There are no clear criteria for 'advanced' Parkinson's disease or for the optimal moment for invasive therapies. There is little evidence regarding the upper limits of levodopa doses, and how these may be influenced by the availability of device-aided therapies. Aim: To analyze substitution therapy in patients with advanced Parkinson's disease. Method: In our retrospective study, we analyzed the data from all patients with advanced Parkinson's disease hospitalized between 1st June 2011 and 31st May 2017, receiving combined levodopa treatment at least 4×/day, reporting a minimum of 2 hours off periods, with or without dyskinesia. We analyzed levodopa therapy for patients who were recommended either device-aided or conservative therapy. Results: Out of 311 patients with advanced Parkinson's disease, for 125 we proposed device-aided therapies whereas in 42 patients we increased the levodopa dose. The average levodopa doses and the administration rate were higher for the 107 patients tested for levodopa-carbidopa intestinal gel. Disease duration, mean levodopa doses and frequency of dosing were all higher in patients proposed for device-aided therapies versus patients with continued conservative treatment. Conclusion: Our patients were on lower levodopa doses (compared to literature), but the combinations were used more often. Device-aided therapies should be considered in patients with severe motor complications who receive at least 750-1000 mg levodopa daily, divided minimum 5×/day. These patients need to be tested in specialized centers by multidisciplinary teams in order to make the best decision for further action. Orv Hetil. 2019; 160(17): 662-669.

Predictors of motor complications in early Parkinson's disease: A prospective cohort study

OBJECTIVE

The objective of this study was to identify clinical predictors of motor complications (dyskinesia and motor fluctuations) of levodopa in a prospectively recruited PD cohort using longitudinal analysis.

METHODS

An inception cohort (Oxford Discovery) of 734 patients was followed to a maximum of 10 years from diagnosis using a discrete-time survival analysis. A subset analysis was used to validate an online dyskinesia-risk calculator developed from the results of the Stalevo Reduction in Dyskinesia Evaluation PD trial.

RESULTS

A total of 186 cases of dyskinesia and 254 cases of motor fluctuations were observed. Dyskinesia incidence increased with time (risk per 100 participants [95% confidence interval] 13 [11-16] <3.5 years, 16 [13-21] 3.5-5.0 years, 19 [14-26] 5-6.5 years, and 23 [16-33] >6.5 years from diagnosis). Motor complication predictors were grouped as medication predictors, disease predictors and patient predictors. Baseline nonmotor feature severity, low mood, anxiety, and age at symptom onset were associated with motor complications among a number of previously identified predictors. Replication of the Stalevo Reduction in Dyskinesia Evaluation PD calculator was reasonable with the area under the curve for dyskinesia risk score as a predictor of dyskinesia being 0.68 (95% confidence interval, 0.55-0.81).

CONCLUSIONS

This study quantifies risk of motor complications, finds consistent predictors, and demonstrates the novel finding that nonmotor features of PD, particularly low mood and anxiety, are significant risk factors for motor complications. Further validation of dyskinesia risk scores are required as well as evidence to determine if the routine use of such scores can be clinically valuable in enhancing patient care and quality of life. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Rasagiline and safinamide as a dopamine-sparing therapy for Parkinson's disease

OBJECTIVES

To evaluate whether the prescription of monoamine oxidase B inhibitors (MAOB-I), rasagiline and safinamide, contributes to the reduction of levodopa and/or dopamine agonists (DA) dose in order to minimize adverse effects.

MATERIALS AND METHODS

A total of 724 patients with Parkinson's disease (PD) have been prospectively included in our database since the year 2000, representing a total of 5124 visits. For each patient and visit, antiparkinsonian treatment was recorded. In the presence of rasagiline and safinamide, we analysed the evolution of levodopa equivalent dose (LED) and LED for DA (LED-DA).

RESULTS

The data obtained from the 1664 visits between 2006 and 2010 (321 patients) and the 1709 visits between 2014 and 2018 (403 patients) were analysed in order to assess the impact of the introduction of rasagiline and safinamide, respectively. The annual mean LED remained stable without statistically significant differences. In the first period (impact of rasagiline), the annual mean LED-DA in 2010 was significantly higher than in 2006 (P = 0.001). In the second period (impact of safinamide), the annual mean LED-DA in 2018 was significantly lower than in 2014 (P = 0.002). A repeated-measure analyses of LED-DA including only patients who had taken safinamide showed a statistically significant decrease in LED-DA (P = 0.027).

CONCLUSIONS

The introduction of MAOB-I in the overall treatment of PD as part of routine clinical practice has not helped to reduce annual mean LED. However, safinamide reduces annual mean LED-DA and may be linked to a reduction in dose-dependent adverse effects in the long term.

Evaluating ADS5102 (amantadine) for the treatment of Parkinson's disease patients with dyskinesia

Introduction: Amantadine is an old, antiviral compound that moderately ameliorates impaired motor behaviour in Parkinson's disease. Its current resurgence results from the novel retarded release amantadine hydrochloride formulation, ADS5102, which has also received approval for the treatment of levodopa-related involuntary movements known as dyskinesia. Areas covered: This non-systematic, narrative drug evaluation discusses the value of ADS5102 for patients with Parkinson's disease. ADS5102 is orally applied once daily in the evening. This capsule provides higher and more continuous amantadine plasma concentrations than conventional amantadine immediate release formulations with their two to three times daily intake plan. Expert opinion: ADS5102 was superior to placebo in clinical trials. They aimed for the amelioration of motor complications, particularly at 'OFF' periods and with dyskinesia in fluctuating levodopa treated patients with Parkinson's disease. Side effects and tolerability were similar to the well-known effects of conventional amantadine formulations. ADS5102 simplifies treatment and improves compliance problems in the long run. The marketing of ADS5102 outside the US will be complex for return of research costs and investments required for its manufacturing. Indeed, worldwide institutional price regulation scenarios often only consider new therapeutic mode of actions as being innovative as opposed to old drugs with improved pharmacokinetic behaviour.

Continuous versus intermittent oral administration of levodopa in Parkinson's disease patients with motor fluctuations: A pharmacokinetics, safety, and efficacy study

BACKGROUND

Laboratory and clinical evidence indicate that continous delivery of levodopa is associated with reduced motor complications compared to standard intermittent levodopa.

OBJECTIVE

To assess the pharmacokinetics and efficacy of continuous oral delivery of l-dopa/carbidopa in PD patients with motor fluctuations.

METHODS

Eighteen PD patients with motor fluctuations were enrolled in an open-label study comparing pharmacokinetics and efficacy measures between standard intermittent oral l-dopa/carbidopa and "continuous" oral l-dopa/carbidopa. Continuous treatment was operationally defined as sips of an l-dopa dispersion at 5- to 10-minute intervals. On day 1, patients received their usual oral l-dopa/carbidopa doses. On day 2, patients received l-dopa/carbidopa dose by "continuous" oral administration. On day 3, patients received a single dose of oral l-dopa/carbidopa followed by continuous administration of l-dopa/carbidopa. Each study period was 8 hours, and the total l-dopa/carbidopa dose administered was the same on each day. Analyses of variability were primarily-based samples drawn between 4 and 8 hours when subjects were in a relative steady state.

RESULTS

There was less variability in plasma l-dopa concentration with continuous versus intermittent oral l-dopa/carbidopa treatment (fluctuation index was 0.99 ± 0.09 vs. 1.38 ± 0.12 [P < 0.001] and coefficient of variation was 0.35 ± 0.03 vs. 0.49 ± 0.04 [P < 0.001]). Mean OFF time was decreased by 43% (P < 0.001) with continuous oral l-dopa therapy. No safety or tolerability issues were observed.

CONCLUSIONS

Continuous oral delivery of l-dopa/carbidopa was associated with less plasma variability and reduced off time in comparison to standard intermittent oral l-dopa/carbidopa therapy. © 2019 International Parkinson and Movement Disorder Society.

Profile Of Patients With Advanced Parkinson's disease Suitable For Device-Aided Therapies: Restrospective Data Of A Large Cohort Of Romanian Patients

BACKGROUND

There is insufficient data in the literature regarding the real-life, daily clinical practice evaluation of patients with advanced Parkinson's disease (APD). We are not sure what is the upper limit of dopaminergic medication, especially the levodopa (LD) dosage, and how it is influenced by access and suitability to the various add-on and device-aided therapies (DAT).

OBJECTIVE

This retrospective study explored the profile of APD patients that were considered and systematically evaluated regarding the suitability for DAT.

METHODS

We analyzed the data from 311 consecutive patients with APD hospitalized between 2011 and 2017 that 1) described at least 2 hrs/day off periods divided into at least two instances/day (except early morning akinesia), 2) were in stage 3 or above on the Hoehn and Yahr scale, 3) were with or without dyskinesia, and 4) received at least four levodopa doses/day combined with adjuvant therapy.

RESULTS

Of the 311 patients enrolled initially, 286 patients showed up for the second visit, of which in 125 cases we assessed that DAT would be necessary. Finally, 107 patients were tested in our clinic to confirm the efficacy of LCIG. Patients selected for DAT had significantly longer off periods, more frequent dyskinesia, early morning akinesia, and freezing despite having significantly higher LD doses than those with an improved conservative therapy.

CONCLUSION

Patients with APD can have a variety of symptoms, and because symptoms and therapeutical efficacy can be manifested in many different combinations, it is not possible to decide using a single, rigid set of criteria which APD patient is eligible for DAT. Nevertheless, treating physicians should refer APD patients to a specialized movement disorder center when patients with an average daily dose of LD of at least 750-1000 mg and maximal complementary therapies present daily motor complications that significantly reduce the quality of life.

L-DOPA for Parkinson's disease-a bittersweet pill

3,4-dihydroxy-L-phenylalanine (L-DOPA) is the gold standard treatment for Parkinson's disease. It has earned that title through its highly effective treatment of some of the motor symptoms in the early stages of the disease but it is a far from perfect drug. The inevitable long-term treatment that comes with this chronic neurodegenerative condition raises the risk significantly of the development of motor fluctuations including disabling L-DOPA-induced dyskinesia. Being unsurpassed as a therapy means that understanding the mechanisms of dyskinesia priming and induction is vital to the search for therapies to treat these side effects and allow optimal use of L-DOPA. However, L-DOPA use may also have consequences (positive or negative) for the development of other interventions, such as cell transplantation, which are designed to treat or repair the ailing brain. This review looks at the issues around the use of L-DOPA with a focus on its potential impact on advanced reparative interventions.

Predictors of Mortality in Nondemented Patients With Parkinson Disease: Motor Symptoms Versus Nonmotor Symptoms

BACKGROUND AND OBJECTIVE

The aim of this study is to identify risk factors for mortality in a community-based cohort of nondemented patients with Parkinson disease (PD) during prospective long-term follow-up, while also comparing the effect of motor complications to nonmotor symptoms (NMS) on risk of mortality.

METHODS

One hundred forty seven nondemented patients with PD (57.1% males; 70.9 ± 8.6 years old) were included in this 48 month follow-up, longitudinal, single, evaluation study. Motor and therapy-related complications were assessed using the Unified Parkinson's Disease Rating Scale/part-IV (UPDRS-IV). Non-Motor Symptoms Scale (NMSS) total score was used to assess NMS burden. Cox proportional hazard models were applied to identify independent predictors of mortality during follow-up.

RESULTS

Twenty-two patients of 146 (15.1%) died (1 case without information). Both UPDRS-IV and NMSS total scores were higher at baseline in patients with PD who died (3.5 ± 3.1 vs 2.4 ± 2.4, P = .049 and 96.9 ± 58.6 vs 61.9 ± 51.0, P = .004, respectively). Unadjusted hazard ratios (HRs) associated with UPDRS-IV and NMSS total scores among those who died during follow-up were 1.171 (95% confidence interval [CI]: 1.012-1.357; P = .035) and 1.008 (95% CI: 1.002-1.013; P = .006), respectively. Independent predictors of mortality during follow-up after adjusting for other covariates were UPDRS-IV (HR: 1.224; 95% CI: 1.002-1.494; P = .047), age (HR: 1.231; 95% CI: 1104-1.374; P < .0001), and comorbidity (Charlson Index; HR: 1.429; 95% CI: 1.023-1.994; P = .036), but not NMSS total score (HR: 1.005; 95% CI: 0.996-1.014; P = .263).

CONCLUSIONS

Both motor complications (UPDRS-IV) and NMS (NMSS) were associated with mortality at 4 years, being motor complications an independent predictor of it.

Early versus Late Application of Subthalamic deep brain Stimulation to Parkinson's disease patients with motor complications (ELASS): protocol of a multicentre, prospective and observational study

INTRODUCTION

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a well-established surgical treatment for Parkinson's disease (PD). However, there is currently no consensus on the best timing for this surgery. The aim of our study is to compare the therapeutic efficacy of bilateral STN DBS in patients with PD with early and late motor complications.

METHODS AND ANALYSIS

200 patients with PD will be enrolled in this multicentre, prospective, observational study, and will be followed up for 4 years. Patients with PD who meet the criteria for STN DBS surgery will be allocated to either the early stimulation group or the late stimulation group based on the duration of their motor complications. The primary outcome will be changes in quality of life from baseline to 4 years, measured using the 39-item Parkinson's Disease Questionnaire Summary Index. The secondary outcomes include changes in motor function measured using Movement Disorder Society-revised Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III, self-reported experiences of daily living measured using MDS-UPDRS Part I B and Part II, good 'on' time recorded by the patients using a diary and safety profile of both groups.

ETHICS AND DISSEMINATION

The study received ethical approval from the Medical Ethical Committee of the First Affiliated Hospital, Sun Yat-sen University. The results of this study will be published in peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT01922388; Pre-results.

Algorithms for the treatment of motor problems in Parkinson's disease

Several different strategies are effective for medical treatment of motor problems in Parkinson's disease (PD). Many guidelines and evidence-based reviews are available, but there is no documentation or consensus in favor of just one treatment strategy. This review presents two algorithms that may be helpful when deciding how to treat a PD patient at various stages of the disease. The first algorithm suggests one way to treat PD from the first onset of motor symptoms. It is largely based on treatment recommendations from the Scandinavian countries and Germany. The other algorithm is meant as assistance for choosing among the different device-aided treatments for advanced PD. There is not sufficient comparative data to recommend one particular line of treatment, neither in early PD nor in advanced disease with motor complications. Individualized treatment is needed for each patient. The current algorithms only represent an alternative for aiding treatment decisions.

L-DOPA-induced dyskinesias, motor fluctuations and health-related quality of life: the COPARK survey

BACKGROUND AND PURPOSE

Studies assessing the correlations between L-DOPA-induced dyskinesias (LIDs) and motor fluctuations with health-related quality of life (HRQoL) in Parkinson's disease (PD) have yielded conflicting results. This study aimed to assess the relationship between LIDs and motor fluctuations with HRQoL in patients with PD, and to assess the relative contribution of their severity and duration in a large sample of patients with PD.

METHODS

A total of 683 patients with PD from the COPARK survey were evaluated. HRQoL was assessed using the 39-Item Parkinson's Disease Questionnaire (PDQ-39) (primary outcome) and 36-Item Short Form Survey (SF-36). The daily duration and severity of LIDs were obtained from Unified Parkinson's Disease Rating Scale (UPDRS) IV items 32 and 33, respectively. The daily duration of motor fluctuations was obtained from UPDRS IV item 36 and severity was estimated as the difference between the UPDRS 2 (Activities of Daily Living) score in 'OFF' versus 'ON' condition.

RESULTS

A total of 235 patients with PD (35%) experienced motor fluctuations and 182 (27%) experienced LIDs. The PDQ-39 total and SF-36 physical scores were significantly worse in patients with LIDs, after adjusting for the presence of motor fluctuations. The PDQ-39 total score and SF-36 physical and mental score were significantly worse in patients with motor fluctuations, after adjusting for the presence of LIDs. The severity of LIDs and the duration of motor fluctuations significantly and independently affected PDQ-39 scores. The SF-36 physical score was affected only by the severity of motor fluctuations, whereas the mental score was not affected by any of the aforementioned variables.

CONCLUSION

Our findings suggest that LIDs (mainly their severity) and motor fluctuations (mainly their duration) correlate independently with HRQoL in patients with PD.

Factors associated with motor complications in Parkinson's disease

OBJECTIVES

Levodopa is the most effective therapy for treating Parkinson's disease (PD); however, side effects such as dyskinesias and motor fluctuations may occur after some years of its usage. The aims of this study were to assess the frequency of and factors associated with motor complications among PD patients on levodopa treatment.

METHODS

In a cross-sectional study carried out in 2010-2013, clinical data and treatment details were collected. Logistic regression expressed by odd ratios (OR) and 95% confidence intervals (CI) was conducted to examine the effects of several independent variables on the occurrence of motor complications.

RESULTS

A total of 455 patients were enrolled, among whom 374 were on levodopa. Analysis was performed in 328 patients whose exact duration of levodopa treatment was known. Among patients included in the analysis, 25.9% experienced motor complications; of these, 21% had dyskinesias and 20.1% had motor fluctuations. Based on logistic regression, statistically significant factors associated with the occurrence of motor complications were younger age at onset of the disease, higher levodopa equivalent daily dose (LEDD), shorter time to levodopa initiation, and akinetic-rigid dominant phenotype of PD.

CONCLUSIONS

This study suggests that postponing the start of levodopa therapy and maintaining low daily doses of levodopa might reduce the risk of motor complications. Our results confirm that due to higher risk of motor complications, effectively treating patients with akinetic-rigid dominant phenotype of PD might be more challenging than for patients whose dominant symptom is tremor.

Disability in Activities of Daily Living and Severity of Dyskinesias Determine the Handicap of Parkinson's Disease Patients in Advanced Stage Selected to DBS

BACKGROUND

There is scarce data on the level of handicap in Parkinson's disease (PD) and none in advanced stage PD.

OBJECTIVE

To assess the handicap in advanced stage PD patients with disabling levodopa-induced motor complications selected to deep brain stimulation (DBS).

METHODS

Data was prospectively recorded during routine evaluation for DBS. Handicap was measured using London Handicap Scale (LHS) (0 = maximal handicap; 1 = no handicap). Disease severity was evaluated using the Hoehn & Yahr scale and the UPDRS/MDS-UPDRS, during off and on after a supra-maximal dose of levodopa. Schwab and England Scale (S&E) was scored in off and on. Dyskinesias were scored using the modified Abnormal Involuntary Movement Scale (mAIMS). Results concern cross-sectional assessment before DBS.

RESULTS

100 PD patients (mean age 61 (±7.6); mean disease duration 12.20 (±4.6) years) were included. Median score of motor MDS-UPDRS was 54 in off and 25 in on. Mean total LHS score was 0.56 (±0.14). Patients were handicapped in several domains with a wide range of severity. Physical Independence and Social Integration were the most affected domains. Determinants of total LHS score were MDS-UPDRS part II off (β= -0.271; p = 0.020), S&E on (β= 0.264; p = 0.005) and off (β= 0.226; p = 0.020), and mAIMS on (β= -0.183; p = 0.042) scores (R2  = 29.6%).

CONCLUSIONS

We were able to use handicap to measure overall health condition in advanced stage PD. Patients were moderately to highly handicapped and this was strongly determined by disability in ADL and dyskinesias. Change in handicap may be a good patient-centred outcome to assess efficiency of DBS.

Polymorphisms of Dopamine Receptor Genes and Risk of L-Dopa-Induced Dyskinesia in Parkinson's Disease

L-dopa–induced dyskinesia (LID) is a frequent motor complication of Parkinson’s disease (PD), associated with a negative prognosis. Previous studies showed an association between dopamine receptor (DR) gene (DR) variants and LID, the results of which have not been confirmed. The present study is aimed to determine whether genetic differences of DR are associated with LID in a small but well-characterized cohort of PD patients. To this end we enrolled 100 PD subjects, 50 with and 50 without LID, matched for age, gender, disease duration and dopaminergic medication in a case-control study. We conducted polymerase chain reaction for single nucleotide polymorphisms (SNP) in both D1-like (DRD1A48G; DRD1C62T and DRD5T798C) and D2-like DR (DRD2G2137A, DRD2C957T, DRD3G25A, DRD3G712C, DRD4C616G and DRD4nR VNTR 48bp) analyzed genomic DNA. Our results showed that PD patients carrying allele A at DRD3G3127A had an increased risk of LID (OR 4.9; 95% CI 1.7–13.9; p = 0.004). The present findings may provide valuable information for personalizing pharmacological therapy in PD patients.

Improvement of dyskinesias with L-dopa infusion in advanced Parkinson's disease

OBJECTIVES

We wanted to investigate whether continuous intrajejunal levodopa-carbidopa intestinal gel (LCIG) therapy has an antidyskinetic effect in patients with Parkinson's disease (PD) and troublesome dyskinesias. We also sought to examine the effect of LCIG therapy on motor function and health-related quality of life (HRQoL).

MATERIALS AND METHODS

This open-label pilot study used a single group pre-post design with follow-up at 6 months. Nine patients with PD who reported to spend at least 3 h per day in on with troublesome dyskinesia were included. The patients were examined at baseline using clinical and self-assessment measures and then switched from peroral/transdermal pharmacotherapy to LCIG therapy. Data collection was repeated 6 months after the pharmaceutical intervention. Nonparametric statistical methods were used for data analyses.

RESULTS

The mean time spent in on with troublesome dyskinesia per day after 6 months of LCIG therapy decreased by 47% (P < 0.05). This observation was paralleled by a 112% increase in mean time spent in on without troublesome dyskinesia (P < 0.01). Patient self-assessment of dyskinesia intensity on the visual analog scale displayed a 90% reduction of mean dyskinesia intensity (P < 0.01) and patients also exhibited less dyskinesia during standardized levodopa tests. Furthermore, we noted improvements in motor function and HRQoL.

CONCLUSIONS

In this pilot study, we found indications that LCIG therapy has a substantial antidyskinetic effect and could be an alternative also for PD patients with dyskinesias as a major symptom. However, further studies with blinded evaluation and larger numbers of patients are warranted to confirm the findings.

Advanced Parkinson disease patients have impairment in prosody processing

BACKGROUND

The ability to recognize and interpret emotions in others is a crucial prerequisite of adequate social behavior. Impairments in emotion processing have been reported from the early stages of Parkinson's disease (PD). This study aims to characterize emotion recognition in advanced Parkinson's disease (APD) candidates for deep-brain stimulation and to compare emotion recognition abilities in visual and auditory domains.

METHOD

APD patients, defined as those with levodopa-induced motor complications (N = 42), and healthy controls (N = 43) matched by gender, age, and educational level, undertook the Comprehensive Affect Testing System (CATS), a battery that evaluates recognition of seven basic emotions (happiness, sadness, anger, fear, surprise, disgust, and neutral) on facial expressions and four emotions on prosody (happiness, sadness, anger, and fear). APD patients were assessed during the "ON" state. Group performance was compared with independent-samples t tests.

RESULTS

Compared to controls, APD had significantly lower scores on the discrimination and naming of emotions in prosody, and visual discrimination of neutral faces, but no significant differences in visual emotional tasks.

CONCLUSION

The contrasting performance in emotional processing between visual and auditory stimuli suggests that APD candidates for surgery have either a selective difficulty in recognizing emotions in prosody or a general defect in prosody processing. Studies investigating early-stage PD, and the effect of subcortical lesions in prosody processing, favor the latter interpretation. Further research is needed to understand these deficits in emotional prosody recognition and their possible contribution to later behavioral or neuropsychiatric manifestations of PD.

Motor complications in an incident Parkinson's disease cohort

BACKGROUND AND PURPOSE

Levodopa treatment in Parkinson's disease (PD) causes motor fluctuations and dyskinesias, but few data describe their development or severity in unselected incident cohorts.

METHODS

Demographic, clinical, treatment, smoking, caffeine and alcohol data from 183 people with PD were gathered from the Parkinsonism Incidence in Northeast Scotland (PINE) study, a community-based, incident cohort. With Kaplan-Meier survival analysis and Cox regression modelling the development, and severity, of dyskinesias and motor fluctuations and which factors independently influenced their onset were assessed.

RESULTS

After a mean follow-up of 59 months, 39 patients (21.3%) developed motor fluctuations and 52 (28.4%) developed dyskinesias. Kaplan-Meier estimates of the probability of motor fluctuations and dyskinesias after 5 years of dopaminergic treatment were 29.2% [95% confidence interval (CI) 21.5%-38.8%] and 37.0% (95% CI 28.5%-47.1%) respectively. 19.8% developed motor fluctuations requiring treatment changes but only 4.0% (95% CI 1.5%-10.4%) developed dyskinesias requiring treatment changes by 5 years. Cumulative levodopa dose [hazard ratio (HR) 1.38 (95% CI 1.19-1.60)], female sex [HR 2.41 (1.19-4.89)] and younger age at diagnosis [HR 1.08 (1.04-1.11)] were independently associated with development of motor fluctuations. Cumulative levodopa dose [HR 1.23 (1.08-1.40)] and female sex [HR 2.51 (1.40-4.51)] were independently associated with dyskinesias. In exploratory analyses, moderate caffeine exposure was associated with fewer motor fluctuations, longer symptom duration with more dyskinesias, and tremor at diagnosis with higher rates of both complications.

CONCLUSIONS

In this community-based incident PD cohort, severe dyskinesias were rare. Cumulative levodopa dose was the strongest predictor of both dyskinesias and motor fluctuations.

Safety of IPX066 , an extended release carbidopa-levodopa formulation, for the treatment of Parkinson's disease

INTRODUCTION

Levodopa (LD) is the most effective treatment for Parkinson's disease (PD). However, chronic use of LD commonly results in the development of motor complications, including wearing off and dyskinesia. The presumption that the short serum half-life of LD is associated with the development of motor complications has raised the need to develop treatments with increased durations of stable LD concentrations.

AREAS COVERED

We conducted a PubMed search for IPX066 articles and also reviewed abstracts from meetings that included this topic. IPX066 is a newly developed formulation of extended release carbidopa-LD (CD-LD) with a one to four ratio of CD to LD, that was approved by the FDA in January 2015 for the treatment of PD, post-encephalitic parkinsonism, and parkinsonism that may follow carbon monoxide or manganese intoxication. It will be marketed by the trade name Rytary®. A Phase III clinical trial showed that IPX066 is efficacious in improving motor symptoms in early PD patients. In advanced PD patients with motor fluctuations, IPX066 reduced off time and increased on time without troublesome dyskinesia compared to CD-LD immediate release and CD-LD with entacapone. IPX066 had an acceptable safety profile. Adverse events of IPX066 from the different trials are presented.

EXPERT OPINION

IPX066 will probably have a role in the treatment of advanced PD with motor fluctuations. IPX066 could also be used initially when LD therapy is prescribed, but the question of whether this usage could reduce or prevent the development of motor complications is yet to be answered.

Dopamine heteroreceptor complexes as therapeutic targets in Parkinson's disease

INTRODUCTION

Several types of D2R and D1R heteroreceptor complexes were discovered in the indirect and direct pathways of the striatum, respectively. The hypothesis is given that changes in the function of the dopamine heteroreceptor complexes may help us understand the molecular mechanisms underlying the motor complications of long-term therapy in Parkinson's disease (PD) with l-DOPA and dopamine receptor agonists.

AREAS COVERED

In the indirect pathway, the potential role of the A2AR-D2R, A2AR-D2R-mGluR5 and D2R-NMDAR heteroreceptor complexes in PD are covered and in the direct pathway, the D1R-D3R, A1R-D1R, D1R-NMDAR and putative A1R-D1R-D3R heteroreceptor complexes.

EXPERT OPINION

One explanation for the more powerful ability of l-DOPA treatment versus treatment with the partial dopamine receptor agonist/antagonist activity to induce dyskinesias, may be that dopamine formed from l-DOPA acts as a full agonist. The field of D1R and D2R heteroreceptor complexes in the CNS opens up a new understanding of the wearing off of the antiparkinson actions of l-DOPA and dopamine receptor agonists and the production of l-DOPA-induced dyskinesias. It can involve a reorganization of the D1R and D2R heteroreceptor complexes and a disbalance of the D1R and D2R homomers versus non-dopamine receptor homomers in the direct and indirect pathways.

Therapeutic strategies to prevent and manage dyskinesias in Parkinson's disease

INTRODUCTION

Chronic treatment with levodopa is associated with the development of motor fluctuations and dyskinesias particularly in young Parkinson patients. In some cases, dyskinesias become so severe that they interfere with normal movement and negatively impact quality of life.

AREAS COVERED

In this review, we discuss benefits and limits of available therapeutic approaches aimed at delaying or managing dyskinesias as well as new strategies that are currently under investigation.

EXPERT OPINION

Among available treatments, monotherapy with dopamine agonists in the early phases of the disease reduces the risk for dyskinesias compared with levodopa. Nevertheless, dopamine agonists are unable to prevent dyskinesias once levodopa is added, which is always required once disease severity progresses. Convincing evidence of dyskinesia improvement has been shown only for deep brain stimulation and to some extent also for duodenal levodopa infusion and subcutaneous apomorphine. These approaches are expensive, have restrictive inclusion criteria and can cause potentially serious side effects. Alternative therapies include drugs targeting nondopaminergic neurotransmitter systems. Amantadine improves dyskinesias but its long-term effect is often unsatisfactory. Glutamatergic and gabaergic compounds have been tested in clinical trials, with promising results. By contrast, adrenergic drugs, fipamezole and idazoxan, did not show antidyskinetic effect.

Pharmacological Treatments Inhibiting Levodopa-Induced Dyskinesias in MPTP-Lesioned Monkeys: Brain Glutamate Biochemical Correlates

Anti-glutamatergic drugs can relieve Parkinson’s disease (PD) symptoms and decrease l-3,4-dihydroxyphenylalanine (l-DOPA)-induced dyskinesias (LID). This review reports relevant studies investigating glutamate receptor subtypes in relation to motor complications in PD patients and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned monkeys. Antagonists of the ionotropic glutamate receptors, such as N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, display antidyskinetic activity in PD patients and animal models such as the MPTP monkey. Metabotropic glutamate 5 (mGlu5) receptor antagonists were shown to reduce the severity of LID in PD patients as well as in already dyskinetic non-human primates and to prevent the development of LID in de novo treatments in non-human primates. An increase in striatal post-synaptic NMDA, AMPA, and mGlu5 receptors is documented in PD patients and MPTP monkeys with LID. This increase can be prevented in MPTP monkeys with the addition of a specific glutamate receptor antagonist to the l-DOPA treatment and also with drugs of various pharmacological specificities suggesting multiple receptor interactions. This is yet to be well documented for presynaptic mGlu4 and mGlu2/3 and offers additional new promising avenues.

A(2A) adenosine receptors and Parkinson's disease severity

OBJECTIVES

In the last decade, increasing evidence suggests a key role of adenosine in Parkinson's disease (PD) and A2A adenosine receptors (A2A ARs) as an important pharmacological target in PD. An overexpression of A2A ARs has been found in putamen and in peripheral blood cells of PD patients. The primary aim of this study was to verify whether the alterations in A2A ARs in lymphocytes of PD subjects correlate with disease severity.

MATERIAL AND METHODS

A consecutive sample of PD patients was enrolled. A clinical examination and a face-to-face interview were carried out. A2A ARs were investigated to verify the affinity and receptor density in lymphocyte membranes. The data were compared with those found in healthy controls. Moreover, the correlation between A2A AR density and affinity and clinical variables was evaluated in PD patients.

RESULTS

In human lymphocyte membranes from PD patients, an increase in A2A AR density and a decrease in A2A AR affinity were found if compared with healthy subjects. A statistically significant correlation between the A2A AR density or affinity and specific clinical parameters as motor and cognitive impairment was detected. Patients with higher A2A AR density and lower affinity were more likely to exhibit motor complications.

CONCLUSIONS

Parkinson's disease patients show an A2A AR upregulation in lymphocyte membranes if compared with healthy subjects. The correlation found between A2A AR density or affinity and clinical parameters highlights the central role of A2A AR modulation in the pharmacological treatment for PD and could suggest the putative role of A2A AR as a candidate biomarker of PD severity.

Adenosine A2A receptor antagonist istradefylline reduces daily OFF time in Parkinson's disease

BACKGROUND

We evaluated the efficacy and safety of istradefylline, a selective adenosine A2A receptor antagonist administered as adjunctive treatment to levodopa for 12 weeks in a double-blind manner in Parkinson's disease patients with motor complications in Japan.

METHODS

A total of 373 subjects were randomized to receive placebo (n=126), istradefylline 20 mg/day (n=123), or istradefylline 40 mg/day (n=124). The primary efficacy variable was the change in daily OFF time. Other secondary variables were also evaluated.

RESULTS

The change in daily OFF time was significantly reduced in the istradefylline 20 mg/day (-0.99 hours, P=.003) and istradefylline 40 mg/day (-0.96 hours, P=.003) groups compared with the placebo group (-0.23 hours). The most common adverse event was dyskinesia (placebo, 4.0%; istradefylline 20 mg/day, 13.0%; istradefylline 40 mg/day, 12.1%).

CONCLUSIONS

Istradefylline reduced daily OFF time and was well tolerated in Japanese PD patients with motor complications on levodopa treatment.