Parkinson's Disease Motor Fluctuations Research Articles

IPX203 vs Immediate-Release Carbidopa-Levodopa for the Treatment of Motor Fluctuations in Parkinson Disease

Levodopa has a short half-life and a limited window of opportunity for absorption in the proximal small intestine. IPX203 is an oral, extended-release formulation of carbidopa-levodopa developed to address these limitations. To assess the efficacy and safety of IPX203 vs immediate-release carbidopa-levodopa in patients with Parkinson disease who are experiencing motor fluctuations. RISE-PD was a 20-week, randomized, double-blind, double-dummy, active-controlled, phase 3 clinical trial. The study was conducted between November 6, 2018, and June 15, 2021, at 105 academic and clinical centers in the US and Europe. Patients with Parkinson disease taking a total daily dose of 400 mg or more of levodopa and experiencing an average of 2.5 hours or more daily off-time were included in the study. A total of 770 patients were screened, 140 were excluded (those taking controlled-release carbidopa-levodopa apart from a single daily bedtime dose, Rytary (Amneal Pharmaceuticals), additional carbidopa or benserazide, or catechol O-methyl transferase inhibitors or who had a history of psychosis within the past 10 years), and 630 were enrolled in the trial. Following open-label immediate-release carbidopa-levodopa dose adjustment (3 weeks) and conversion to IPX203 (4 weeks), patients were randomized in a 1:1 ratio to double-blind, double-dummy treatment with immediate-release carbidopa-levodopa or IPX203 for 13 weeks. The primary end point was mean change in daily good on-time (ie, on-time without troublesome dyskinesia) from baseline to the end of the double-blind treatment period. A total of 630 patients (mean [SD] age, 66.5 [8.95] years; 396 [62.9%] men) were enrolled, and 506 patients were randomly assigned to receive IPX203 (n = 256) or immediate-release carbidopa-levodopa (n = 250). The study met its primary end point, demonstrating statistically significant improvement in daily good on-time for IPX203 compared to immediate-release carbidopa-levodopa (least squares mean, 0.53 hours; 95% CI, 0.09-0.97; P = .02), with IPX203 dosed a mean 3 times per day vs 5 times per day for immediate-release carbidopa-levodopa. Good on-time per dose increased by 1.55 hours with IPX203 compared to immediate-release carbidopa-levodopa (95% CI, 1.37-1.73; P < .001). IPX203 was well tolerated. The most common adverse events in the double-blind phase (IPX203 vs immediate-release carbidopa-levodopa) were nausea (4.3% vs 0.8%) and anxiety (2.7% vs 0.0%). In this study, IPX203 provided more hours of good on-time per day than immediate-release carbidopa-levodopa, even as IPX203 was dosed less frequently. ClinicalTrials.gov Identifier: NCT03670953.

Clinical Utility of Opicapone in the Management of Parkinson's Disease: A Short Review on Emerging Data and Place in Therapy.

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder, and levodopa (L-dopa) remains the most efficacious drug treatment for PD and a gold-standard for symptom control. Nonetheless, a significant majority of PD patients develop motor fluctuations over their disease course, with a significant impact on quality-of-life, meaning control of such complications translates into a fundamental clinical need. Catechol-O-methyl transferase (COMT) inhibitors (COMT-i) are used as first-line adjuvant therapy to L-dopa for end-of-dose (EoD) motor fluctuations, since they increase L-dopa availability in the brain by inhibiting its peripheral metabolism. Opicapone (OPC), a once-daily, long-acting COMT-i, is the most recent and potent of its class, having been licensed in Europe in 2016 as an add-on to preparations of L-dopa/DOPA decarboxylase inhibitors in PD patients with EoD motor fluctuations. More recently, it has also received approval in the USA and Japan in 2020. Two high-quality positive efficacy studies (double-blind Phase III clinical trials) established OPC efficacy with significant reduction in OFF time (average 60 minutes vs placebo), without concomitant increase of distressing dyskinesias during ON time. These beneficial effects were sustained in open-label extension studies, without unexpected safety issues or adverse events, with dyskinesia having been the most frequent complaint. OPC also avoids liver toxicity and gastrointestinal issues compared with previous COMT-i. In this review, we aimed to cover OPC’s lifecycle (synthesis to commercialization), its clinical pharmacological data, safety, tolerability and pharmacovigilance evidence, and discuss its role in the management of motor fluctuations in PD as well as its emerging place in international recommendations.

Effect of the mGlu2 positive allosteric modulator CBiPES on dyskinesia, psychosis-like behaviours and parkinsonism in the MPTP-lesioned marmoset.

Advanced Parkinson's disease (PD) is often complicated by the occurrence of dyskinesia, motor fluctuations and psychosis. To this day, few treatment options are available for each of these phenomena, and they are at times not effective or elicit adverse events, leaving some patients short of therapeutic options. We have recently shown that positive allosteric modulation of metabotropic 2 (mGlu2) receptors with the prototypical positive allosteric modulator (PAM) LY-487,379 is efficacious at alleviating both dyskinesia and psychosis-like behaviours (PLBs), while simultaneously enhancing the anti-parkinsonian action of L-3,4-dihydroxyphenylalanine (L-DOPA), in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned marmoset. Here, we assessed the effects of CBiPES, a mGlu2 PAM derived from LY-487,379, but with improved pharmacokinetic properties. Six MPTP-lesioned marmosets with reproducible dyskinesia and PLBs were administered L-DOPA in combination with vehicle or CBiPES (0.1, 1 and 10mg/kg), after which their behaviour was rated. CBiPES 10mg/kg reduced global dyskinesia by 60% (P < 0.0001), while peak dose dyskinesia was reduced by 66% (P < 0.001), compared to L-DOPA/vehicle. CBiPES 10mg/kg also diminished global PLBs by 56% (P < 0.0001), while peak dose PLBs were reduced by 64% (P < 0.001), compared to L-DOPA/vehicle. Lastly, CBiPES enhanced the anti-parkinsonian action of L-DOPA, by reducing global parkinsonian disability by 43% (P < 0.01), compared to L-DOPA/vehicle. Our results provide further evidence that mGlu2 positive allosteric modulation may be an approach that could be efficacious for the treatment of dyskinesia, psychosis and motor fluctuations in PD.

Safety Profile of Opicapone in the Management of Parkinson's Disease.

Opicapone is a catechol O-methyltransferase (COMT) inhibitor indicated for use as adjunct to levodopa therapy in patients with Parkinson's disease (PD) and motor fluctuations. To characterize the safety and tolerability of adjunct opicapone (25 and 50 mg) in a pooled population of levodopa-treated PD patients who participated in the opicapone Phase-3 clinical program. Patient-level data (placebo, opicapone 25 mg and 50 mg) from the BIPARK-1 and BIPARK-2 double-blind and open-label studies were combined. Pooled analyses included 766 patients from the double-blind studies and 848 patients from the open-label studies. In the double-blind studies, 63.3% of opicapone-treated patients reported treatment-emergent adverse events (TEAEs) versus 57.2% in the placebo group. The most common TEAEs reported in the opicapone group compared to placebo were dyskinesia, constipation and insomnia. The incidence of serious TEAEs was similar across opicapone and placebo groups (3.5% versus 4.3%, respectively). Overall, 71.3% patients treated with open-label opicapone reported at least one TEAE; most occurred within the first 2 months of the open-label studies, and then decreased thereafter. Throughout the Phase-3 clinical program, there were no serious AEs suggestive of hepatic toxicity, and the incidence of gastrointestinal disorders such as nausea and diarrhea remained low (<2%). There were no relevant changes in laboratory parameters including liver enzymes, vital signs, physical or neurological examinations, or ECG readings. Long-term use of opicapone once-daily over 1-year at doses of 25 mg or 50 mg was generally safe and well tolerated, supporting its clinical usefulness in the management of PD motor fluctuations.

Influence of motor fluctuations duration, levodopa dose and duration of use in efficacy responses of Parkinson's disease patients: Post-hoc analysis from combined BIPARK-I and II

To evaluate the impact of motor fluctuations (MF) duration, levodopa dose and levodopa duration of use (LDU) in efficacy responses of levodopa-treated Parkinson's Disease (PD) patients with MF. Opicapone (OPC), a once-daily COMT inhibitor, proved effective in the treatment of MF in PD in two large, pivotal, multinational trials (BIPARK-I and II) [[1]Ferreira et al.Lancet Neurol. 2016; 15: 154-165Google Scholar,[2]Lees et al.JAMA Neurol. 2017; 74: 197-206Google Scholar]. Patient-level data from matching treatment arms in BIPARK-I and II were combined in placebo (PLC) and OPC-50 mg groups. Studies had similar designs (primary efficacy endpoint: change from baseline in patient diaries-based absolute OFF-time) and eligibility criteria [[1]Ferreira et al.Lancet Neurol. 2016; 15: 154-165Google Scholar,[2]Lees et al.JAMA Neurol. 2017; 74: 197-206Google Scholar]. This post-hoc analysis assessed influence of MF duration (years), levodopa dose (mg) and LDU (years) in efficacy outcomes (OFF-/ON-time change from baseline). Applied linear regression's slope was statistically tested for deviation from zero. 1027 patients were randomized to BIPARK-I and II; Full Analysis Set comprised 517 [PLC (n = 255); OPC-50 mg (n = 262)]. Due to lack of matched-patients, four OPC-50 mg patients (MF > 12 years) were excluded from MF analysis and two PLC (<1 year) and five OPC-50 mg (>18 years) patients were excluded from LDU analysis. Mean baseline values were 2.4 (PLC) to 2.5 (OPC-50 mg) years of MF, 696 mg (PLC) to 698 mg (OPC-50 mg) of levodopa and 6.4 (PLC) to 6.0 (OPC-50 mg) years of use. OFF-/ON-time magnitude of responses was not influenced by any parameter. Linear regression was non-significant for each arm and variables analyzed. MF duration, levodopa dose and LDU do not appear to impact OFF-/ON-time magnitude of responses in a clinical study setting.

Implementing Levodopa-Carbidopa Intestinal Gel for Parkinson Disease: Insights from US Practitioners.

BackgroundLevodopa‐carbidopa intestinal gel (LCIG, designated in the United States as carbidopa‐levodopa enteral suspension, CLES) was approved in the United States in 2015 for the treatment of refractory motor fluctuations in individuals with Parkinson disease (PD). Many neurologists in the United States have not had personal experience with implementation and management of the unique delivery system for this treatment.Methods and FindingsThis educational review was developed to provide practitioners with an understanding of LCIG use from the clinician's point of view. Practical recommendations for the use of LCIG from the early planning stages through long‐term patient management were compiled from the published literature, regulatory guidance, and clinical experience. Among the topics reviewed were: assembling a multidisciplinary treatment team, identifying treatment candidates, patient/care partner education, procedural considerations, post‐procedural care, LCIG initiation and titration, troubleshooting issues, and ongoing monitoring. For most of these steps, a considerable amount of individualization is possible, which allows clinicians to tailor protocols based on the needs of their teams, the healthcare system, and the patient and care partner. Although clinical practices are heterogeneous, themes of early planning, ongoing education, and a team‐based approach to management are universal.ConclusionsBy using established protocols and insights gleaned from experienced practitioners, clinicians who are unfamiliar with LCIG can more feasibly incorporate this treatment option into their armamentarium for treating PD motor fluctuations.

A Kinematic Sensor and Algorithm to Detect Motor Fluctuations in Parkinson Disease: Validation Study Under Real Conditions of Use.

BackgroundA new algorithm has been developed, which combines information on gait bradykinesia and dyskinesia provided by a single kinematic sensor located on the waist of Parkinson disease (PD) patients to detect motor fluctuations (On- and Off-periods).ObjectiveThe goal of this study was to analyze the accuracy of this algorithm under real conditions of use.MethodsThis validation study of a motor-fluctuation detection algorithm was conducted on a sample of 23 patients with advanced PD. Patients were asked to wear the kinematic sensor for 1 to 3 days at home, while simultaneously keeping a diary of their On- and Off-periods. During this testing, researchers were not present, and patients continued to carry on their usual daily activities in their natural environment. The algorithm’s outputs were compared with the patients’ records, which were used as the gold standard.ResultsThe algorithm produced 37% more results than the patients’ records (671 vs 489). The positive predictive value of the algorithm to detect Off-periods, as compared with the patients’ records, was 92% (95% CI 87.33%-97.3%) and the negative predictive value was 94% (95% CI 90.71%-97.1%); the overall classification accuracy was 92.20%.ConclusionsThe kinematic sensor and the algorithm for detection of motor-fluctuations validated in this study are an accurate and useful tool for monitoring PD patients with difficult-to-control motor fluctuations in the outpatient setting.

Perceived Treatment Status of Fluctuations in Parkinson Disease Impacts Suicidality

On/off motor fluctuations in Parkinson disease (PD) can be associated with extreme mood fluctuations and severe dysphoria. The impact of these affective symptoms may be overlooked in the treatment of motor fluctuations. Our goal was to examine the relationship between motor fluctuations, their treatment status, and suicidality in PD participants. We analyzed data from the Methods of Optimal Depression Detection in Parkinson's Disease (MOOD-PD) study of 223 individuals with PD. Suicidality was measured using items from four depression scales: Hamilton Depression Rating Scale (HAM-D-17); Montgomery-Åsberg Depression Rating Scale (MADRS); Inventory for Depressive Symptomatology (IDS-C); and the self-rated Beck Depression Inventory (BDI). Multivariable Poisson regression analyses tested whether self-reported motor fluctuations and their treatment status were associated with suicidality while controlling for recognized risk factors. Thirty-seven participants (16.6%) self-reported suicidality and 89 (39.5%) self-reported motor fluctuations, of whom 21 (23.6%) perceived their fluctuations as untreated. Participants reporting untreated motor fluctuations more frequently had a current depressive disorder (p < 0.001) and endorsed suicidality (p = 0.006) than participants with treated or no fluctuations. They also had significantly higher total scores on the HAM-D-17, MADRS, IDS-C, and BDI depression scales (p < 0.001 for each). Regression analyses showed significant associations between untreated motor fluctuations and higher scores on suicide questions extracted from the HAM-D-17, MADRS, and IDS-C (p < 0.01 for each). PD patients with untreated motor fluctuations are at increased risk for suicidal thoughts and should be monitored for mood changes as treatment is adapted.

Tablet-Based Application for Objective Measurement of Motor Fluctuations in Parkinson Disease

Background: The motor subscale of the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS-III) has limited applicability for the assessment of motor fluctuations in the home setting. Methods: To assess whether a self-administered, tablet-based application can reliably quantify differences in motor performance using two-target finger tapping and forearm pronation-supination tasks in the ON (maximal dopaminergic medication efficacy) and OFF (reemergence of parkinsonian deficits) medication states, we recruited 11 Parkinson disease (PD) patients (age, 60.6 ± 9.0 years; disease duration, 12.8 ± 4.1 years) and 11 healthy age-matched controls (age, 62.5 ± 10.5 years). The total number of taps, tap interval, tap duration, and tap accuracy were algorithmically calculated by the application, using the more affected side in patients and the dominant hand in healthy controls. Results: Compared to the OFF state, PD patients showed a higher number of taps (84.2 ± 20.3 vs. 54.9 ± 26.9 taps; p = 0.0036) and a shorter tap interval (375.3 ± 97.2 vs. 708.2 ± 412.8 ms; p = 0.0146) but poorer tap accuracy (2,008.4 ± 995.7 vs. 1,111.8 ± 901.3 pixels; p = 0.0055) for the two-target task in the ON state, unaffected by the magnitude of coexistent dyskinesia. Overall, test-retest reliability was high (r >0.75) and the discriminatory ability between OFF and ON states was good (0.60 ≤ AUC ≤ 0.82). The correlations between tapping data and MDS-UPDRS-III scores were only moderate (–0.55 to 0.55). Conclusions: A self-administered, tablet-based application can reliably distinguish between OFF and ON states in fluctuating PD patients and may be sensitive to additional motor phenomena, such as accuracy, not captured by the MDS-UPDRS-III.

Parkinson Kinetic Graph: Are Motor Fluctuations in Parkinson Disease Related with Disease Duration?

Introduction: The Parkinson’s KinetiGraph (PKG) is a digital measurement system for motor fluctuations (FS). The aim of this study is to investigate whether FS, measured by the PKG, are associated with disease duration of Parkinson’s Disease (PD) patients. Material and Methods: 172 PD were included. PKG measurements, clinical data and disease duration were collected. Patients were categorized in four disease duration categories (0 - 5 years, 6 - 7 years, 8 - 11 years and ≥12 years). Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis. Results: The mean age of the patients is 69.2 years (SD ± 8.13). Disease duration varies between 1 and 28 years. Significant difference was found between the four disease categories in FS (p = 0.050); between group 1 - 3, p = 0.005. Conclusions: As expected, FS measured by PKG increase during disease progression in PD. In advanced disease stages, FS stabilise, indicating that PKG is the most useful in early and moderate stages of PD.

Assessment of Nonmotor Fluctuations Using a Diary in Advanced Parkinson’s disease

Since previous studies aimed to study nonmotor symptom (NMS) fluctuations in direct conjunction with motor oscillations, there are no data available on the temporal context of NMS fluctuations and motor oscillations in advanced Parkinson's disease (PD). To evaluate circadian patterns and temporal connections of NMS and motor fluctuations in PD. 15 controls, 17 non-fluctuating and 15 fluctuating PD patients completed two diaries by rating 4 key psychiatric (anxiety, depressive mood, inner restlessness, concentration/attention deficits), fatigue and 4 autonomic NMS (excessive sweating, sialorrhea, bladder urgency, dizziness) absent or present and motor function (Off, On with/without dyskinesia, and asleep) for every hour for 5 consecutive days. NMS Off state hours (hours with NMS rated as present) were less frequent compared to motor Off state hours and NMS On-Off-switches were less prevalent compared to those of the motor state. Off time and number of On-Off-switches of psychiatric NMS were moderately correlated with motor Off time and number of motor On-Off switches on the individual patient level. Changes in NMS state occurred largely independent of changes in motor states with concordance rates of only 26-43% of all NMS changes for psychiatric and 7-17% for autonomic NMS. In controls and non-fluctuating PD patients, there were no NMS state switches in concordance to motor state switches. We provide first data on the temporal context of NMS fluctuations showing similar frequencies of psychiatric NMS Off, fatigue Off and motor Off times as well as their On-Off-fluctuations, but low concordance rates of NMS with motor On-Off-state switches. We found no evidence for NMS fluctuations in non-fluctuating PD patients. Our data implicate similar fluctuation patterns of mood NMS and motor function without close timing and/or different kinetics.

Multimodal fusion for functional rehabilitation at home

Conventional musculoskeletal rehabilitation consists of a therapy consultancy, an exercise assignment, and an execution task with or without assistance of the therapist. This classical approach consumes plenty of the patient's time, money and effort, and especially those of medical staff. Serious games have been studied as an aided tool for clinical and home-based rehabilitation, with patient autonomy in the exercise execution but monitored by the therapist staff. In order to estimate joint angles, most of these systems used a Kinect camera for musculoskeletal rehabilitation motion but the estimation accuracy represents the principal drawback. Therefore, in this work, which is under development, we have proposed a data fusion system based on accelerometers devices (Shimmer) and Kinect camera. Figure 1 shows that wearable sensors can be used to closely monitor Parkinson's disease motor fluctuations and predict clinical scores with high accuracy. Exploiting a quaternion representation of orientation, we propose to estimate joint angle from Shimmer sensors using a gradient descent algorithm, which is based on accelerometer and magnetometer signals (magnetic distortion has been taken into account). The estimated orientation will be fused with the calculated orientation using angular rate signal. The weighted sum fusion algorithm is used. The output of the fusion algorithm is used to continuously correct Kinect camera output. Below, in Figure 1 , we describe the general workflow of the proposed system. The system will be able to inform the user in real time the successful completion of the rehabilitation exercises.

Actively Transported Levodopa Prodrug XP21279

The objectives of this study were to assess the pharmacokinetic profile, efficacy, and safety of XP21279 administered with carbidopa (CD) in subjects with Parkinson disease (PD) experiencing motor fluctuations and explore dose correspondence between CD-levodopa (LD) and XP21279 administered with CD. Subjects received CD-LD 3 or 4 times daily for 2 weeks, followed by XP21279 plus CD 3 times daily for 2 weeks at fixed dosing times, allowing dose adjustment to optimize clinical response, in this multiple-dose, multicenter, open-label, 2-period, sequential-treatment study. Pharmacokinetic parameters, including LD exposure, were assessed over 16 hours on the last day of each treatment period. Levodopa exposure variability was assessed for each treatment using the absolute % deviation from average concentration (Cavg) in each subject. Efficacy assessments included daily self-ratings of OFF time, ON time, and dyskinesias. XP21279 provided significantly less variability in LD concentration compared with CD-LD (P < 0.05) in 10 PD subjects with motor fluctuations, consistent with lower peak-to-trough fluctuation for XP21279. Patterns of percentage of subjects OFF were consistent with the LD concentration-time profiles for each respective treatment. Compared with CD-LD treatment, 6 of 10 study completers experienced reduction of 30% or greater in average daily OFF time during the last 4 days in the XP21279 treatment period. XP21279 resulted in an increase in the time spent ON without troublesome dyskinesias, and the mean time to ON after the first morning XP21279 dose was not delayed, as compared with CD-LD. XP21279 provided improved pharmacokinetic performance (highlighted by reduction in variability of LD concentration) compared with CD-LD and therefore may provide better control of PD motor fluctuations.

Feasibility of home-based automated Parkinson's disease motor assessment

Patients with Parkinson's disease (PD) receive therapies aimed at addressing a diverse range of motor symptoms. Motor complications in the form of symptom fluctuations and dyskinesias that commonly occur with chronic PD medication use may not be effectively captured by Unified Parkinson's Disease Rating Scale (UPDRS) assessments performed in the clinic. Therefore, home monitoring may be a viable adjunct tool to provide insight into PD motor symptom response to treatment. In this pilot study, we sought to evaluate the feasibility of capturing PD motor symptoms at home using a computer-based assessment system. Ten subjects diagnosed with idiopathic PD used the system at home and ten non-PD control subjects used the system in a laboratory. The Kinesia system consists of a wireless finger-worn motion sensor and a laptop computer with software for automated tremor and bradykinesia severity score assessments. Data from control subjects were used to develop compliance algorithms for rejecting motor tasks performed incorrectly. These algorithms were then applied to data collected from the PD subjects who used the Kinesia system at home to complete motor exams 3–6 times per day over 3–6 days. Motor tasks not rejected by the compliance algorithms were further processed for symptom severity. PD subjects successfully completed motor assessments at home, with approximately 97% of all motor task data files (1222/1260) accepted. These findings suggest that objective home monitoring of PD motor fluctuations is feasible.

Clinical Experiences With Levodopa Methylester (Melevodopa) in Patients With Parkinson Disease Experiencing Motor Fluctuations

Slow gastric emptying decreasing levodopa (LD) bioavailability contributes to motor fluctuations in Parkinson disease (PD). Melevodopa (LD methylester), ensuring rapid duodenal absorption, has been proposed as rescue therapy for afternoon off periods. To assess daily motor fluctuations by multiple administrations of Sirio (Chiesi Farmaceutici SpA, Parma, Italy) (melevodopa/carbidopa) in PD patients. In this open-label naturalistic study, 75 PD patients (group A) completely switched standard LD (Sinemet or Madopar) with Sirio at an equivalent dosage (800-1000 mg/d). One hundred nineteen PD patients (group B) partially replaced their standard LD (Sinemet) with Sirio at an equivalent dosage (400-500 mg/d) while continuing Stalevo 100. In both groups, the observational period lasted 6 months. Assessments included an on/off diary, the Unified Parkinson's Disease Rating Scale (motor examination [UPDRS II] and activities of daily living [UPDRS III]), the dyskinesia scale, and an adverse event profile. Group A showed a significant reduction of afternoon off hours at 6 months (P < 0.05). Forty-five patients (69%) reported a subjective early onset of on motor response. Twelve patients (18.5%) reported its shorter duration. The dyskinesia scale score remained unchanged. Ten patients (13.3%) discontinued melevodopa for gastric intolerance. Group B showed at 6 months a significant reduction of total hours of daily off periods (P < 0.05), particularly in the morning (P < 0.01) and afternoon (P < 0.05). Seventy subjects (59%) expressed positive judgment on quickness of onset of on motor response. The dyskinesia scale score was unchanged. No significant adverse events were reported. Switching PD patients with motor fluctuations to melevodopa, particularly in the presence of entacapone, could optimize critical periods of the day such as the morning delay on and afternoon off periods.

Motor complications in patients form the German Competence Network on Parkinson's disease and the DRD3 Ser9Gly polymorphism

In addition to levodopa treatment and disease duration, genetic predisposition might contribute to the development of medication-related complications in Parkinson's disease (PD). As recent observations indicate the dopamine D(3) receptor (DRD3) to modulate both therapeutic action of levodopa and dyskinesia, we reappraised the impact of the DRD3 Ser9Gly polymorphism on development of motor complications in a large scale association study based on the gene bank of the German Competence Network on Parkinson's disease. Stepwise regression analysis revealed no effect of DRD3 Ser9Gly on chorea, dystonia, or motor fluctuations in PD, despite incorporating established clinical risk factors to avoid overlooking an effect of genotype. Duration of PD was confirmed as the most important clinical risk factor, followed by age of disease onset and female sex. Additional studies incorporating grading of motor complications, and combinations of risk genotypes, are warranted.

Chronic subthalamic deep brain stimulation improves pain in Parkinson disease

Pain is a well recognized feature of Parkinson disease (PD). Like motor fluctuations, pain in PD may fluctuate as 'non-motor fluctuations'. Subthalamic deep brain stimulation (STN DBS) is an established treatment for motor fluctuations in PD. However, the effect of STN DBS on the pain in PD is only partially investigated. PD patients who were considered for STN DBS were asked if they had pain. The severity of pain was scored in each body part. In patients with motor fluctuation, the pain in the 'on' and 'off ' state were recorded separately. Patients were evaluated preoperatively and 3 months after surgery. Some patients were followed for 6 months. Twenty-three of 29 patients had pain preoperatively. Of 24 with motor fluctuation, 21 had pain, and 18 had fluctuating pain. Pain improved in 20 out of 23 with preoperative pain at 3 months postoperatively. Of 18 with fluctuating pain, 12 reported a decrease in, and 5 complete disappearance of the 'off ' pain. Of 4 with nonfluctuating preoperative pain, 2 reported improvement. Pain was severe and functionally disabling in some. The STN DBS improved pain to a tolerable degree. In 7 of 29, new pain developed during the 3 month follow-up. Sixteen patients were followed for 6 months. All 11 patients who had improvement at 3 months continued to get benefit from STN DBS. Two additional patients who had no improvement at 3 months reported improvement at 6 months. Pain is frequent in PD and STN DBS improves pain, especially the 'off ' pain in PD.

Levodopa/DDCI and entacapone is the preferred treatment for Parkinson’s disease patients with motor fluctuations in routine practice: a retrospective, observational analysis of a large French cohort

Levodopa is the gold standard drug for the symptomatic control of Parkinson's disease (PD). However, long-term treatment with conventional formulations [levodopa and a dopa decarboxylase inhibitor (DDCI)], is associated with re-emergence of symptoms because of wearing-off and dyskinesia. Treatment with levodopa/DDCI and entacapone extends the half-life of levodopa, avoiding deep troughs in levodopa plasma levels and providing more continuous delivery of levodopa to the brain. In this open-label, retrospective, observational study we investigated the effects of levodopa/DDCI and entacapone therapy in 800 PD patients with motor fluctuations. Levodopa/DDCI and entacapone treatment was assessed as good/very good in improving motor fluctuations (64%) and activities of daily living (ADL; 62%). The therapeutic utility was considered to be good/very good in 70% of cases. Moreover, there was a reduction in levodopa dose in 20% of patients. Neurologists preferred levodopa/DDCI and entacapone compared with increasing levodopa dosage, dose-fractionation or addition of a dopamine agonist (63%, 29% and 23% of patients respectively). Reasons included achieving more continuous dopaminergic stimulation (40%), reducing motor fluctuations (54%) and improving ADL (41%). This analysis reveals the preference of neurologists for levodopa/DDCI and entacapone over conventional levodopa-modification strategies for the effective treatment of PD motor fluctuations in clinical practice.

Effects of Nebicapone on Levodopa Pharmacokinetics, Catechol-O-methyltransferase Activity, and Motor Fluctuations in Patients with Parkinson Disease

To investigate the effects of nebicapone, a new catechol-O-methyltransferase (COMT) inhibitor, on levodopa pharmacokinetics, COMT activity, and motor fluctuations in Parkinson disease in comparison to placebo and entacapone. Randomized, double-blind, placebo-controlled, 4-way crossover study consisting of 4 treatment periods (6-9 days duration each) in 19 patients (65.3 +/- 8.5 years) treated with carbidopa/levodopa 3 to 7 times per day. Nebicapone/entacapone/placebo and carbidopa/levodopa doses were administered concomitantly. At the end of each period, a levodopa test was performed, and levodopa and 3-O-methyldopa levels and COMT activity were assayed. After 75 mg nebicapone, 150 mg nebicapone, and 200 mg entacapone, levodopa area under the plasma concentration time curve significantly increased 28.1, 48.4, and 33.3%, and 3-O-methyldopa area under the plasma concentration time curve significantly decreased 59.2, 70.8, and 59.1%, respectively. Peak COMT inhibition was similar between active treatments, but extent of COMT inhibition was more sustained with 75 and 150 mg nebicapone than with 200 mg entacapone. After the levodopa test doses, ON time significantly increased 29 minutes with 75 mg nebicapone, 45 minutes with 150 mg nebicapone, and 16 minutes with 200 mg entacapone. Patients' diaries showed a decrease in daily OFF time of 109 minutes with 75 mg nebicapone, 103 minutes with 150 mg nebicapone, and 71 minutes with 200 mg entacapone, and an increase in daily ON time of 74, 101, and 74 minutes, respectively. Treatments were generally well tolerated and safe; no relevant changes in liver function tests were reported. Nebicapone, a new COMT inhibitor, significantly decreased COMT activity, increased systemic exposure to levodopa, and improved motor response. Nebicapone deserves further evaluation in larger samples of patients.

Pisa syndrome as a motor complication of Parkinson's disease

We describe two elderly patients with a convincing clinical diagnosis of Parkinson's disease (PD) who developed axial end-of-dose/off dystonia, also referred to as Pisa syndrome (PS). The worsening of symptoms in the “off” period, and a favorable response of the dystonia to an increase of levodopa suggests that PS in our patients may be primarily related to a manifestation of motor fluctuations in PD.