Efficacy of combining levodopa with entacapone on quality of life and activities of daily living in patients experiencing wearing-off type fluctuations

Effectiveness and safety of different catechol-o-methyl transferase inhibitors for patients with parkinson's disease: Systematic review and network meta-analysis

BACKGROUND

Levodopa treatment requires the addition of other drugs, such as catechol-O-methyl transferase (COMT) inhibitors, to alleviate motor fluctuations in advanced parkinson's disease (PD). However, the optimal strategy, including the type and dose of COMT inhibitors remains unknown. This systematic review and network meta-analysis aimed to assess the efficacy and safety of different COMT inhibitors and for treating PD patients.

METHODS

PubMed, Embase, Cochrane Library and Web of Science were screened up to November 20, 2022. Randomized controlled trials (RCTs) of COMT inhibitors (entacapone, opicapone, tolcapone) for PD patients were included. Eligible outcomes were total ON-time, rate of ON-time >1 h, total daily dose of levodopa therapy, mean change from baseline to final follow up in Unified Parkinson's Disease Rating Scale (UPDRS) part III scores, adverse events and dyskinesia. Network meta-analyses integrated direct and indirect evidence with placebo as a common comparator.

RESULTS

We identified 18 studies with 7564 patients. Opicapone, entacapone, and tolcapone could increase total ON-time when compared with placebo. However, opicapone (25 mg, MD 4.0, 95%CrI: 1.1-7.5) and opicapone (50 mg, MD 5.1, 95%CrI: 2.2-8.7) statistically significant increase the total ON-time. opicapone and entacapone could increase the rate of ON-time >1 h when compared with placebo. Only opicapone (5 mg) showed no statistically significant with placebo (OR 1.4, 95%CrI: 0.74-2.4). We found that opicapone (50 mg, SURCA, 0.796) is the best option compared with other treatments. TOL (200 mg) was ranked highest in the rank probability test for total daily dose of levodopa therapy, followed by OPI (50 mg), TOL (400 mg) and TOL (100 mg) in order. SUCRA rankings identified TOL (200 mg) as the most likely therapy for increasing adverse events (SUCRA 27.19%), followed by TOL (400 mg, SUCRA 27.20%) and OPI (5 mg, SUCRA 30.81%). The SUCRA probabilities were 91.6%, 75.2%, 67.9%, 59.3%, 45.6%, 41.1%, 35.1%, 24.6% and 9.4% for PLA, TOL (400 mg), ENT (100 mg), ENT (200 mg), OPI (5 mg), TOL (100 mg), OPI (25 mg), OPI (50 mg), and TOL (200 mg) respectively.

CONCLUSION

In conclusion, opicapone (50 mg) may be a better choice for treatment PD when compared with other COMT inhibitors.

Comparative efficacy and safety of adjunctive drugs to levodopa for fluctuating Parkinson's disease - network meta-analysis

It remains unclear which adjunctive drug for Parkinson's disease (PD) in combination with levodopa is more effective, tolerable, and safe. We aimed to compare the efficacy, tolerability, and safety among anti-PD drugs from several classes in patients with fluctuating PD who received levodopa through network meta-analysis (NMA). Twelve anti-PD drugs belonging to 4 different drug classes (dopamine agonists, monoamine oxidase type B inhibitors, catechol-O-methyl transferase inhibitors, and an adenosine A2A receptor antagonist) were selected. We systematically searched PubMed, Embase, and the Cochrane Library for eligible randomized controlled trials (RCTs) comparing placebo with anti-PD drug or among anti-PD drugs in patients with PD who experienced motor fluctuations or wearing-off and received levodopa. We included 54 RCTs in the analysis. The NMA was performed under a frequentist framework using a random-effects model. The efficacy outcome was change in daily off-time, and the tolerability outcome was discontinuation due to all causes. Safety outcomes included discontinuation due to adverse events (AEs) and the incidence of AEs, dyskinesia, hallucination, and orthostatic hypotension. According to the surface under the cumulative ranking curve (SUCRA) in the NMA, ropinirole transdermal patch (SUCRA, 0.861) ranked the highest in efficacy, followed by pramipexole (0.762), ropinirole extended release (ER) (0.750), and safinamide (0.691). In terms of tolerability, ropinirole (0.954) ranked the highest, followed by pramipexole (0.857), safinamide (0.717), and ropinirole ER (0.708). Each anti-PD drug had different SUCRA ranking profiles for the safety outcomes. These findings suggest that ropinirole, pramipexole, and safinamide are well-balanced anti-PD drugs that satisfy both efficacy and tolerability outcomes.

Clinical benefit of MAO-B and COMT inhibition in Parkinson's disease: practical considerations

Inhibitors of monoamine oxidase B (MAO-B) and catechol-O-methyltransferase (COMT) are major strategies to reduce levodopa degradation and thus to increase and prolong its effect in striatal dopaminergic neurotransmission in Parkinson's disease patients. While selegiline/rasagiline and tolcapone/entacapone have been available on the market for more than one decade, safinamide and opicapone have been approved in 2015 and 2016, respectively. Meanwhile, comprehensive data from several post-authorization studies have described the use and specific characteristics of the individual substances in clinical practice under real-life conditions. Here, we summarize current knowledge on both medication classes, with a focus on the added clinical value in Parkinson's disease. Furthermore, we outline practical considerations in the treatment of motor fluctuations and provide an outlook on ongoing studies with MAO-B and COMT inhibitors.

COMT Inhibitors in the Management of Parkinson's Disease

Levodopa treatment remains the gold standard for Parkinson's disease, but shortcomings related to the pharmacological profile, notably, oral administration and the consequent occurrence of motor complications, have led to the development of several add-on levodopa treatments or to research to improve the method of delivery. Motor fluctuations, and to a lesser extent non-motor fluctuations, concern half of the patients with Parkinson's disease after 5 years of disease and patients identified them as one of their most bothersome symptoms. Catechol-O-methyl transferase inhibitors (COMT-Is) are one of the recommended first-line levodopa add-on therapies for the amelioration of end-of dose motor fluctuations in patient with advanced Parkinson's disease. Currently, two peripheral COMT-Is are considered as first-line choices - entacapone (ENT), which was approved by the US Food and Drug Administration in 1999 and the European Committee in 1998; and opicapone (OPC), which was approved by the European Committee in 2016. A second-line COMT-I that requires regular hepatic monitoring, tolcapone (TOL), was approved by the Food and Drug Administration in 1998 and the European Committee in 1997. Of note, OPC also received Food and Drug Administration approval in 2021, but it is still only marketed in a few countries, including Germany, UK, Spain, Portugal, Italy, Japan, and USA, while ENT and TOL have a wider market. Our narrative review summarizes the pharmacokinetic/pharmacodynamic properties, clinical efficacy in terms of motor fluctuations, motor/non-motor symptoms, quality of life, and safety data of these three COMT-Is, as evidenced by randomized clinical trials, as well as by real-life observational studies. Overall, a phase III non-inferiority trial showed a similar effect between ENT and OPC on off-time (-60.8 min/day and -40.3 min/day, vs placebo, respectively), with a possible additional off-time reduction of 39 min/day, obtained when there is a switch from ENT to OPC. Concomitantly, TOL can reduce off-time by an average of 98 min/day. A significant though discrete concomitant reduction on the Unified Parkinson's Disease Rating Scale motor section (2-3 points) is obtained with all three drugs vs placebo. Data on quality of life are fewer and more heterogeneous, with positive results obtained especially in open-label studies. Effects on non-motor symptoms were investigated as secondary outcome only in a few studies, frequently by means of non-specific scales and a benefit was observed in open-label studies. Dopaminergic adverse effects were the most frequent, dyskinesia being the most common for the three drugs eventually requiring levodopa dose reductions. No urine discoloration and a very low incidence of diarrhea were found with OPC compared with ENT and TOL. Regular hepatic monitoring is needed only for TOL. A combination of COMT-Is with new formulations of levodopa, including the subcutaneous, intrajejunal, or new extended-release formulation, merits further exploration to improve the management of both mild and severe motor fluctuations.

Different Catechol-O-Methyl Transferase Inhibitors in Parkinson's Disease: A Bayesian Network Meta-Analysis

Parkinson's disease (PD) is a common, chronic, progressive, debilitating neurodegenerative disease. The current levodopa treatment requires the addition of other drugs, such as catechol-O-methyl transferase (COMT) inhibitors, to alleviate motor fluctuations in advanced PD. Therefore, a theoretical reference for treatment is urgently needed. In this study, an appropriate search strategy was used to screen eligible studies on different drugs to treat patients with PD from the Embase, PubMed, and Cochrane Library. The publication dates were from January 1990 to June 2021. We integrated eligible randomized controlled trials, and statistical analysis was performed on three kinds of effectiveness outcomes and two types of safety outcomes. We assessed the average difference or odds ratio between each drug and placebo and summarized them as the average and 95% confidence interval (CI), respectively. In terms of efficacy, entacapone (mean difference [MD], 0.64 h; 95% CI, 0.29–1.0), opicapone (MD, 0.92 h; 95% CI, 0.35–1.5), and tolcapone (MD, 3.2 h; 95% CI, 2.1–4.2) increased patients' total ON-time compared to placebo. Tolcapone (MD, −100 mg; 95% CI −160 to −45) reduced the total daily dose of levodopa therapy. None of these three drugs was found to have statistical significance in mean change from baseline in UPDRS part III scores when compared with others. In terms of safety, tolcapone (MD, 3.8; 95% CI, 2.1–6.8), opicapone (MD, 3.7; 95% CI, 2–7.2), and entacapone (MD, 2.2; 95% CI, 1.5–3.3) increased the number of cases of dyskinesia compared to placebo. Entacapone (MD, 1.7; 95% CI, 1.3–2.2) and tolcapone (MD, 4.3; 95% CI, 1.3–15) were more likely to cause adverse events than placebo. In conclusion, opicapone showed higher efficiency and fewer safety problems in five indicators we selected when compared with the other two drugs.

Adverse effects produced by different drugs used in the treatment of Parkinson's disease: A mixed treatment comparison

OBJECTIVE

This mixed treatment comparison is used to compare the adverse effects of eleven different drugs used to treat Parkinson's disease (PD). The drugs that we compare include the following: ropinirole, rasagiline, rotigotine, entacapone, apomorphine, pramipexole, sumanirole, bromocriptine, piribedil, pergolide, and levodopa.

METHODS

PubMed, EMBASE, and Cochrane Library were searched from the inception to December 2015. Our analysis combines the evidences of direct comparison and indirect comparison between various literatures. We evaluated the merging odds ratios (OR) value and surface under the cumulative ranking curves (SUCRA) of each of the drugs and used this as a mode of comparison.

RESULTS

Twenty-four randomized controlled trials (RCTs) were included in this study. Our results demonstrated that the incidence of adverse reactions of ropinirole, rotigotine, entacapone, and sumanirole were obviously higher in terms of nausea compared to the placebo. Ropinirole produced the highest incidence rates of dyskinesia side effects, whereas pramipexole was significantly higher in terms of patients' hallucination. In addition, the SUCRA values of all the drugs showed that the incidence of adverse reaction of pergolide was relatively high (nausea: 83.5%; hallucination: 79.8%); for dyskinesia and somnolence, the incidence of ropinirole was higher (dyskinesia: 80.5%; somnolence: 69.4%); the incidence of adverse reaction of piribedil was higher on PD in terms of dizziness (67.0%); and the incidence of bromocriptine was relatively high in terms of constipation (62.3%).

CONCLUSIONS

This mixed treatment comparison showed that the drugs ropinirole, bromocriptine, and piribedil produced the highest incidence rates of nausea, dyskinesia, hallucination, dizziness, constipation, and somnolence symptoms. Thus, we conclude that as these three drugs produced the most frequent symptoms, they are not recommended for the treatment of patients with Parkinson's disease.

Efficacy and Safety of Adjuvant Treatment with Entacapone in Advanced Parkinson's Disease with Motor Fluctuation: A Systematic Meta-Analysis

AIMS

To assess the efficacy and safety of adjuvant treatment with entacapone in the treatment of later Parkinson's disease (PD) patients with motor fluctuation.

METHODS

We conducted a systematic review of relevant studies from 8 databases to June 23, 2016.

RESULTS

Fourteen studies were included in this review (n = 2,804). The results showed that compared with placebo, adjuvant therapy with entacapone significantly increased on time (p < 0.01) and reduced off time (p < 0.01), the required levodopa (LD) dose (p < 0.01) and improved Parkinson's Disease Rating Scale (UPDRS) scores (activities of daily living score: p < 0.01; motor score: p < 0.01; UPDRS I-III score: p > 0.05). However, the withdrawal (OR 1.44, 95% CI 1.10-1.89, p < 0.01) due to adverse events and adverse events rates including nausea (OR 2.23, 95% CI 1.56-3.20, p < 0.01), urine discoloration (OR 14.99, 95% CI 7.63-29.44, p < 0.01), gastrointestinal disorder (OR 2.6, 95% CI 1.89-3.57, p < 0.01) and dyskinesia (OR 2.00, 95% CI 1.56-2.58, p < 0.01) increased in patients with entacapone compared with those given a placebo .

CONCLUSIONS

This meta-analysis suggests that the entacapone used as adjuvant therapy to LD is effective in the management of later PD with fluctuation. However, patients on entacapone had a higher frequency of adverse events than those on placebo but no occurrence of severe adverse reactions.

LSVT-BIG Improves UPDRS III Scores at 4 Weeks in Parkinson’s Disease Patients with Wearing Off: A Prospective, Open-Label Study

The efficacy of LSVT-BIG for advanced Parkinson’s disease (PD) patients with wearing off remains to be determined. Therefore, we evaluated whether LSVT-BIG improves motor disability in eight PD patients with wearing off. Unified Parkinson’s Disease Rating Scale (UPDRS) scores, daily off time, and mobility assessments were evaluated during the “on” time before and after the LSVT-BIG course. LSVT-BIG significantly improved UPDRS III scores at 4 weeks and UPDRS II scores in the “off” state at 12 weeks, with no changes in the other measures. The findings suggest that LSVT-BIG may be an effective therapy for advanced PD patients with wearing off.

Impact of Pharmacotherapy on Quality of Life in Patients with Parkinson's Disease

Quality of life (QoL) is a patient-reported outcome frequently included in Parkinson's disease (PD) clinical trials as a secondary or tertiary endpoint. However, QoL is an important variable that reflects the impact of disease and treatment from the patients' perspective. In a chronic, neurodegenerative disease such as PD, with a wide range of complex symptoms, QoL provides valuable and comprehensive information on the patients' health status. This narrative review aims to evaluate the effect of specific PD treatments currently in use on patients' QoL measured with the Parkinson's Disease Questionnaire, 39-item (PDQ-39) or 8-item (PDQ-8) version. A quantification of this effect is provided by calculation of the relative change and effect size. These two parameters allow an intuitive standardized approach to the importance of change based on its magnitude. Some high-quality studies (Level I) were found for levodopa (immediate- or extended-release formulations), levodopa with added-on catechol-O-methyltransferase (COMT) inhibitors, levodopa/carbidopa gel for intestinal infusion, some dopamine agonists (ropinirole, cabergoline, pergolide), and the monoamine oxidase B (MAO-B) inhibitor safinamide. As a whole, these studies found a beneficial effect of variable magnitude, weak to moderate, on patients' QoL. Studies with a lower level of evidence or not providing enough data to estimate relative change and effect size, including those for the apomorphine subcutaneous pump, also reported improvement of QoL, but the evidence was insufficient to confirm the effect. More high-quality studies focused on QoL are needed to determine the real impact of PD drug treatments for this important outcome.

Pharmacological strategies for the management of levodopa-induced dyskinesia in patients with Parkinson's disease

L-Dopa-induced dyskinesias (LID) are the most common adverse effects of long-term dopaminergic therapy in Parkinson's disease (PD). However, the exact mechanisms underlying dyskinesia are still unclear. For a long time, nigrostriatal degeneration and pulsatile stimulation of striatal postsynaptic receptors have been highlighted as the key factors for the development of LID. In recent years, PD models have revealed a wide range of non-dopaminergic neurotransmitter systems involved in pre- and postsynaptic changes and thereby contributing to the pathophysiology of LID. In the current review, we focus on therapeutic LID targets, mainly based on agents acting on dopaminergic, glutamatergic, serotoninergic, adrenergic, and cholinergic systems. Despite a large number of clinical trials, currently only amantadine and, to a lesser extent, clozapine are being used as effective strategies in the treatment of LID in clinical settings. Thus, in the second part of the article, we review the placebo-controlled trials on LID treatment in order to disentangle the changing scenario of drug development. Promising results include the extension of L-dopa action without inducing LID of the novel monoamine oxidase B- and glutamate-release inhibitor safinamide; however, this had no obvious effect on existing LID. Others, like the metabotropic glutamate-receptor antagonist AFQ056, showed promising results in some of the studies; however, confirmation is still lacking. Thus, to date, strategies of continuous dopaminergic stimulation seem the most promising to prevent or ameliorate LID. The success of future therapeutic strategies once moderate to severe LID occur will depend on the translation from preclinical experimental models into clinical practice in a bidirectional process.

Willingness to pay for a new drug delivery in Parkinson patients

Objective

The Swedish reimbursement system operates a system where prices are set based on the expected value to the consumer. This value can be measured using willingness to pay (WTP).

Aim

To assess Parkinson’s disease (PD) patients’ WTP for newly developed microtablets of levodopa in combination with a drug-delivering electronic device (M/E) compared to standard treatment with levodopa in combination with the COMT (catechol-O-methyl transferase)-inhibitor entacapone (L/e).

Method

A total of 2,000 randomly included PD patients had a postal questionnaire covering demographics, disease-specific issues, views on medication and WTP in different hypothetical scenarios. The first scenario was M/E with no change in effects or side effects; the second scenario was M/E with same effect and less side effects; and the third scenario was M/E with improved effect and less side effects. These scenarios were coupled to different costs to choose from.

Results

A total of 999 patients (50%) responded, mean age of 71 years and a mean PD duration of 9 years. Of all respondents, 50% preferred M/E before L/e in scenario one with increasing preference to scenario three. The average monthly WTP among all respondents in scenario one was SEK 230 and SEK 226 in L/e, both with an almost longitudinal doubling up to scenario three. Duration of PD-related symptoms, high education, and high medication intake implied a higher WTP in all scenarios in contrast to age, sex, and extra doses of levodopa.

Conclusion

WTP for M/E increased gradually with high medication intake and education as well as with expected increased reduction of PD symptoms.

Efficacy of levodopa/carbidopa/entacapone versus levodopa/carbidopa in patients with early Parkinson's disease experiencing mild wearing-off: a randomised, double-blind trial

To compare the efficacy and safety of levodopa/carbidopa/entacapone (LCE) with levodopa/carbidopa (LC) on Parkinson's disease (PD) patients with mild, or only minimally disabling motor complications. A prospective 3-month, multicentre, parallel-group, double-blind, and randomised phase IV study was performed. The primary endpoint was to assess the efficacy of LCE compared to LC on ADLs using the UPDRS part II. Secondary endpoints were assessed by the UPDRS (I, III and IV) scores, QUICK and PDQ-39 questionnaires, and patient and investigator clinical global impression (CGI). Ninety-five patients were randomly assigned to treatment with LCE (100/25/200 or 150/37.5/200 mg tablets, n = 46) or LC (100/25 mg tablets, n = 49), at the same levodopa dose that were administered before randomization. Treatment with LCE resulted in significantly greater improvement in UPDRS part II (ADLs) scores compared to treatment with LC (adjusted mean difference between groups of -1.5 points) (p = 0.0288). Amelioration was also observed in UPDRS part III scores (p = 0.010), and CGI (patient and investigator) scores (p = 0.015, and p = 0.028, respectively). LCE and LC were generally well tolerated with 78 % of subjects completing the study. Most AEs (50 % in LCE and 71.4 % in LC) were classified as mild. No serious AEs were related to the treatment. Treatment with LCE results in improved efficacy compared to LC in PD patients with mild, or minimally disabling motor fluctuations, maintaining a good safety and tolerability profile.

Summary of the recommendations of the EFNS/MDS-ES review on therapeutic management of Parkinson's disease

OBJECTIVE

To summarize the 2010 EFNS/MDS-ES evidence-based treatment recommendations for the management of Parkinson's disease (PD). This summary includes the treatment recommendations for early and late PD.

METHODS

For the 2010 publication, a literature search was undertaken for articles published up to September 2009. For this summary, an additional literature search was undertaken up to December 2010. Classification of scientific evidence and the rating of recommendations were made according to the EFNS guidance. In cases where there was insufficient scientific evidence, a consensus statement ('good practice point') is made.

RESULTS AND CONCLUSIONS

For each clinical indication, a list of therapeutic interventions is provided, including classification of evidence.

Review: management of Parkinson's disease

Parkinson's disease (PD) is one of the most frequent neurological diseases. Despite the modern imaging and nuclear techniques which help to diagnose it in a very early stage and lead to a better discrimination of similar diseases, PD has remained a clinical diagnosis. The increasing number of available treatment options makes the disease management often complicated even when the presence of PD seems undoubted. In addition, nonmotor symptoms and side effects of some therapies constitute some pitfalls already in the preclinical state or at the beginnings of the disease, especially with the progressive effect on patients. Therefore, this review aimed to summarize study results and depict recommended medical treatments for the most common motor and nonmotor symptoms in PD. Additionally, emerging new therapeutic options such as continuous pump therapies, eg, with apomorphine or parenteral levodopa, or the implantation of electrodes for deep brain stimulation were also considered.

How to treat Parkinson's disease in 2013

Parkinson's disease is a common, progressive, debilitating disease with substantial physical, psychological and social implications. Pharmacological management is complex and should be individualised according to the needs of the patient. In early disease, treatment is generally highly effective, but medication becomes increasingly inadequate in controlling motor fluctuations and dyskinesias as the disease progresses. Non-motor symptoms, especially depression and dementia, require a holistic, multidisciplinary approach to maximise quality of life for patients and their carers. For the future, the ideal solution remains neuroprotection and restoration. Progress has been hampered by the lack of animal models that reflect the widespread brain pathology presumed to cause both motor and non-motor symptoms of PD in humans. Currently, agents are undergoing clinical trials in early, mildly affected patients, such as the plant-derived substance PYM50028 (Cogane), which promotes expression of endogenous neural growth factors and has shown promise in vitro and in animal models. Gene-therapy trials in progress rely on the viral vectors used to deliver the enzymatic machinery required for dopamine synthesis to the striatum. As PD progresses, adequate control of motor symptoms depends increasingly on continuous drug delivery, and greater physiological stimulation of dopamine receptors may help to prevent the development of LIDs and motor fluctuations. Efforts thus are afoot to develop better delivery systems for levodopa, and a new sustained-release formulation is in development.

Health-related quality of life as an outcome variable in Parkinson's disease

In the past three decades, health-related quality of life (HRQoL) has become an outcome variable in Parkinson's disease clinical trials. This review considers the measuring tools that have been developed, suitability of data reporting, complexity of outcome interpretation, and clinical application to provide evidence regarding available therapeutic interventions to date. In the introduction, different terms regarding quality of life are clearly defined. The methodology section offers an overview of generic, disease specific, and recommended HRQoL scales in Parkinson's disease and the most important psychometric attributes a scale should meet. The interpretation of HRQoL outcomes is complex and not intuitive. Thus, appropriate reporting of data is crucial in order to calculate relative change, a result that facilitates understanding to what extent an intervention is beneficial. The concept of minimally important change/difference is explained as well as the different approaches to its calculation (anchor-based and distribution-based methods). In the results section, a brief overview of the impact on HRQoL of currently available treatments in Parkinson's disease is provided. Special emphasis is given to data assessment, highlighting reports that helped understanding of the clinical significance of the intervention and therefore aided in making therapeutic decisions. The discussion section emphasizes the need for more clinical trials with HRQoL as a primary outcome and standardized reporting in order to further our understanding of the complexity of treatment effects and make evidence-based clinical decisions regarding HRQoL in patients with Parkinson's disease.

The Movement Disorder Society Evidence-Based Medicine Review Update: Treatments for the motor symptoms of Parkinson's disease

The objective was to update previous evidence-based medicine reviews of treatments for motor symptoms of Parkinson's disease published between 2002 and 2005. Level I (randomized, controlled trial) reports of pharmacological, surgical, and nonpharmacological interventions for the motor symptoms of Parkinson's disease between January 2004 (2001 for nonpharmacological) and December 2010 were reviewed. Criteria for inclusion, clinical indications, ranking, efficacy conclusions, safety, and implications for clinical practice followed the original program outline and adhered to evidence-based medicine methodology. Sixty-eight new studies qualified for review. Piribedil, pramipexole, pramipexole extended release, ropinirole, rotigotine, cabergoline, and pergolide were all efficacious as symptomatic monotherapy; ropinirole prolonged release was likely efficacious. All were efficacious as a symptomatic adjunct except pramipexole extended release, for which there is insufficient evidence. For prevention/delay of motor fluctuations, pramipexole and cabergoline were efficacious, and for prevention/delay of dyskinesia, pramipexole, ropinirole, ropinirole prolonged release, and cabergoline were all efficacious, whereas pergolide was likely efficacious. Duodenal infusion of levodopa was likely efficacious in the treatment of motor complications, but the practice implication is investigational. Entacapone was nonefficacious as a symptomatic adjunct to levodopa in nonfluctuating patients and nonefficacious in the prevention/delay of motor complications. Rasagiline conclusions were revised to efficacious as a symptomatic adjunct, and as treatment for motor fluctuations. Clozapine was efficacious in dyskinesia, but because of safety issues, the practice implication is possibly useful. Bilateral subthalamic nucleus deep brain stimulation, bilateral globus pallidus stimulation, and unilateral pallidotomy were updated to efficacious for motor complications. Physical therapy was revised to likely efficacious as symptomatic adjunct therapy. This evidence-based medicine review updates the field and highlights gaps for research.

Treatment of motor symptoms in advanced Parkinson's disease: a practical approach

Patients with advanced Parkinson's disease (PD) are known to develop motor complications after a few years of levodopa (L-dopa) therapy. Motor fluctuations develop with increasing severity of the disease, owing to loss of dopaminergic neurons and loss of the buffering capacity of the neurons to fluctuating dopamine levels. Dyskinesias develop as a result of pulsatile stimulation of the receptors and alterations in neuronal firing patterns. L-dopa remains the gold standard medication for the treatment of patients with advanced PD. However, once motor complications on L-dopa therapy emerge, clinicians may add on other classes of antiparkinsonian drugs such as dopamine agonists, catechol-O-methyl transferase inhibitors (COMTIs) or monoamine oxidase type B inhibitors (MAOBIs). The individualisation of the treatment seems to be the key for the best approach of advanced PD patients. The present review provides the most important current clinical data in the pharmacological treatment of motor symptoms in advanced PD and provides the clinician a simple algorithm in order to determine the best suitable treatment to advanced parkinsonian patients.

Strategies for Parkinson’s disease care: prevention and management of motor fluctuations

SUMMARY Parkinson’s disease (PD) is characterized clinically by the hallmark motor signs of bradykinesia, rest tremor and rigidity. Current pharmacological management goals include control of motor symptoms as well as prevention and management of motor complications including motor fluctuations and dyskinesias. While the use of levodopa revolutionized the pharmacological management of PD, multiple other agents and strategies have emerged with many demonstrable, albeit sometimes controversial, advantages to a ‘levodopa’ only approach. Despite these developments, the progressive nature of PD requires vigilance and creativity from clinicians as both motor and nonmotor complications grow in number and severity over time.

Treatment of idiopathic Parkinson's disease with traditional chinese herbal medicine: a randomized placebo-controlled pilot clinical study

The objective of this clinical study is to examine the effects of a Chinese herbal medicine formula (Jia Wei Liu Jun Zi Tang: JWLJZT) on motor and non-motor symptoms, and on complications of conventional therapy in idiopathic Parkinson's disease (PD), using an add-on design. Fifty-five patients with PD were randomly allocated to receive either Chinese herbal medicine or placebo for 24 weeks. Primary outcome measure was the 39-item Parkinson's Disease Questionnaire (PDQ-39). Secondary outcome measures included the Unified Parkinson's Disease Rating Scale (UPDRS), Short-Form-36 Health Survey (SF-36), Geriatric Depression Scale (GDS), home diaries, and a range of category rating scales. JWLJZT resulted in a significant improvement in the UPDRS IVC when compared with placebo at 12 weeks (P = .039) and 24 weeks (P = .034). In addition, patients in the Chinese herbal medicine group also showed significant improvement in PDQ-39 communication scores at 12 weeks (P = .024) and 24 weeks (P = .047) when compared with the placebo group. There were no significant differences between treatment and control groups for SF-36 variables, GDS score or the mean daily "on-off" time. One case of mild diarrhea was noted in the treatment group. The findings suggest that JWLJZT can relieve some non-motor complications of conventional therapy and improve the communication ability in patients with PD. The results of this pilot study warrant larger multi-center clinical studies to assess long-term efficacy and tolerability of JWLJZT, and to elucidate the mechanisms by which it affects PD function.

Therapeutic interventions and adjustments in the management of Parkinson disease: role of combined carbidopa/levodopa/entacapone (Stalevo)

Parkinson disease (PD) is a neurodegenerative disorder characterized by 3 cardinal motor symptoms: resting tremor, rigidity, and bradykinesia. Since its introduction 40 years ago, levodopa has represented the gold standard for dopaminergic stimulation therapy in patients with PD. Levodopa is routinely combined with a dopa-decarboxylase inhibitor (DDCI) to prevent the conversion of levodopa into dopamine in peripheral circulation. However, up to 80% of patients treated with continuous levodopa manifest the onset of disabling motor complications capable of producing an adverse effect on quality of life as the disease progresses. In recent years, a new, safe, and efficacious armamentarium of treatment options has been provided by the marketing of the catechol-O-methyltransferase (COMT) inhibitor, entacapone, a peripheral blocker of dopa to 3-0-methyldopa metabolism, which increments levodopa brain availability. When administered with levodopa, entacapone conjugates the rapid onset of levodopa-induced effects with a protracted efficiency, thus providing additional benefits to classic levodopa treatment by increasing "on" time in fluctuating PD patients, and theoretically providing a more continuous and physiological-like stimulation of dopamine receptors implying a reduced risk of motor complications. In this context, the use of a single administration of combined carbidopa/ levodopa/entacapone (Stalevo(®)) in the treatment of PD affords clinical improvements similar to those obtained by 2 separate tablets (ie, levodopa/DDCI and entacapone), although the former produces a more positive effect on quality of life than the latter. Additionally, the STalevo Reduction In Dyskinesia Evaluation (STRIDE-PD) study was designed with the aim of demonstrating that the combination of levodopa, carbidopa, and entacapone, used as initial levodopa therapy, significantly delays the onset of dyskinesias compared with the conventional levodopa/carbidopa formulation. Unfortunately, STRIDEPD failed to prove the benefit of continuous dopaminergic stimulation with triple therapy in a clinical setting. Recently, the effect of combined COMT inhibitor with levodopa administration in reducing homocysteine synthesis has been described. To this regard, clear evidence has been presented indicating homocysteine as a risk factor for vascular diseases, cognitive impairment, and dementia. Several studies have discussed the potential of entacapone as adjunct to levodopa/ DDCI in reducing plasma homocysteine levels with contrasting results.

Evaluation of the efficacy and safety of adjuvant treatment to levodopa therapy in Parkinson s disease patients with motor complications

BACKGROUND

One of the complications of long-term treatment of Parkinson's disease (PD) with levodopa is the development of motor complications. Generally, when motor complications develop, clinicians add in an additional drug (to the levodopa regimen) from one of three other classes of anti-Parkinsonian treatments (dopamine agonists, catechol-O-methyl transferase inhibitors (COMTIs) or monoamine oxidase type B inhibitors (MAOBIs)). However, despite trials having shown that these drugs are beneficial compared to placebo, it remains unclear as to the best way to treat patients experiencing motor complications and whether one class of drug is more effective than another.

OBJECTIVES

This meta-analysis aims to assess more reliably the benefits and risks of the three classes of drugs (dopamine agonists, COMTIs and MAOBIs) currently used as adjuvant treatment to levodopa in PD patients suffering from motor complications. The three drug classes were compared with the aim of determining whether one class of drug provides better symptomatic control than another.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library), MEDLINE, EMBASE, PubMed, LILACS and Web of Science, plus major journals in the field, abstract books, conference proceedings and reference lists of retrieved publications.

SELECTION CRITERIA

Randomised trials comparing an orally administered dopamine agonist, COMTI or MAOBI versus placebo, both on a background of levodopa therapy, in PD patients experiencing motor complications.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data on off-time, levodopa dose, motor complications, side-effects, treatment concordance, clinician-rated disability, mortality, quality of life and health economic data.

MAIN RESULTS

Forty-four eligible trials, involving 8436 participants were identified. Compared to placebo, adjuvant therapy significantly reduced off-time (-1.05 hours/day, 95% confidence interval (CI) -1.19 to -0.90; P<0.00001), the required levodopa dose (-55.65 mg/day, CI -62.67 to -48.62; P<0.00001) and improved UPDRS scores (UPDRS ADL score: -1.31 points, CI -1.62 to -0.99; P<0.00001; UPDRS motor score: -2.84 points, CI -3.36 to -2.32; P<0.00001; UPDRS total score: -3.26 points, CI -4.52 to -2.00; P<0.00001). However, dyskinesia (odds ratio (OR) 2.50, CI 2.21 to 2.84; P<0.00001) and side-effects including constipation (OR 3.19, CI 2.17 to 4.68; P<0.00001), dizziness (OR 1.57, CI 1.30 to 1.90; P<0.00001), dry mouth (OR 2.33, CI 1.22 to 4.47; P=0.01), hallucinations (OR 2.16, CI 1.70 to 2.74; P<0.00001), hypotension (OR 1.47, CI 1.18 to 1.83; P=0.0007), insomnia (OR 1.38, CI 1.09 to 1.74; P=0.007), nausea (OR 1.78, CI 1.53 to 2.07; P<0.00001), somnolence (OR 1.87, CI 1.40 to 2.51; P<0.0001) and vomiting (OR 2.56, CI 1.67 to 3.93; P<0.0001) were all increased with adjuvant therapy.Indirect comparisons of the three drug classes suggested that dopamine agonists were more efficacious in reducing off-time (dopamine agonist: -1.54 hours/day; COMTI: -0.83 hours/day; MAOBI: -0.93 hours/day; test for heterogeneity between drug classes P=0.0003) and levodopa dose (dopamine agonist: -116 mg/day; COMTI: -52 mg/day; MAOBI: -29 mg/day; test for heterogeneity between drug classes P<0.00001). UPDRS scores also improved more with dopamine agonists than with COMTI or MAOBI (UPDRS total scores - dopamine agonist: -10.01 points versus COMTI: -1.46 points versus MAOBI: -2.20 points; test for heterogeneity between drug classes P<0.00001), although more dyskinesia were seen with dopamine agonists (OR 2.70) and COMTI (OR 2.50) than with MAOBI (OR 0.94) (test for heterogeneity between drug classes P=0.009). Although the increase in the overall incidence of side-effects was generally more marked with dopamine agonists (OR 1.52) and COMTI (OR 2.0) than with MAOBI (OR 1.32), heterogeneity between drug classes was only of borderline significance (P=0.07).

AUTHORS' CONCLUSIONS

Compared to placebo, adjuvant therapy reduces off-time, levodopa dose, and improves UPDRS scores in PD patients who develop motor complications on levodopa therapy. However, this is at the expense of increased dyskinesia and numerous other side-effects. Indirect comparisons suggest that dopamine agonist therapy may be more effective than COMTI and MAOBI therapy, which have comparable efficacy. However, as indirect comparisons should be interpreted with caution, direct head-to-head randomised trials assessing the impact of these different drug classes on overall patient-rated quality of life are needed.

The wearing-off phenomenon and the use of questionnaires to facilitate its recognition in Parkinson's disease

Long-term treatment of Parkinson's disease (PD) with dopaminergic therapy is associated with a re-emergence of PD symptoms, referred to as wearing-off. Signs of wearing-off encompass motor symptoms, such as slowness of movement and stiffness, and non-motor symptoms, including anxiety and fatigue. Both motor and non-motor symptoms impact significantly on the function and quality of life of PD patients. Early detection and management of wearing-off has been shown to improve patient symptoms; however, identification of wearing-off, particularly the non-motor symptoms, is hampered by a lack of patient education, awareness, patient-physician communication, and limited time for evaluation. Several questionnaires have been developed to aid the detection of wearing-off. This review investigates the development and use of the Wearing-Off Questionnaires (WOQ-32, WOQ-19, and WOQ-9), as well as their sensitivity and specificity in identifying wearing-off. The manuscript also provides an overview of the motor and non-motor signs of wearing-off and highlights the available treatment strategies for managing this potentially debilitating phenomenon.

The impact of levodopa on quality of life in patients with Parkinson disease

BACKGROUND

Parkinson disease (PD) is associated with a progressive decline in patient quality of life (QoL), because of motor and nonmotor manifestations of PD and treatment-related side effects.

REVIEW SUMMARY

Treatment with carbidopa/levodopa-the current gold standard therapy-improves QoL in the short term, but gains are not maintained over a long term. Long-term treatment is associated with symptom re-emergence (end-of-dose "wearing off") and development of dyskinesia, which may have an adverse impact on QoL.

CONCLUSIONS

Levodopa (LD; combined with carbidopa) remains the gold standard for symptomatic treatment of PD, but long-term treatment is associated with complications that may adversely affect QoL. Recent studies have suggested that the addition of a catechol-O-methyltransferase inhibitor may improve QoL through the reduction of some of the motor complications of LD therapy. Further studies are required to determine the full effects of this as well as other treatments that are used to manage LD-associated complications on QoL.

Responsiveness of the EQ-5D and 8-item Parkinson's Disease Questionnaire (PDQ-8) in a 4-year follow-up study

OBJECTIVE

The purpose of this study was to evaluate the responsiveness of the EQ-5D and the Parkinson's Disease Questionnaire (PDQ-8) to deterioration in health-related quality of life (HRQoL) in patients with Parkinson's disease (PD).

METHODS

HRQoL and clinical data collected from 31 patients with PD (male: 74.2%, mean age: 61 years) who were surveyed with the EQ-5D and the PDQ-8 questionnaires in 2002 and 2006/2007 were analyzed. Responsiveness of the EQ-5D, PDQ-8, and Hoehn and Yahr (H&Y) staging were assessed according to Cohen's effect size (ES) and standardized response mean (SRM).

RESULTS

The mean (standard deviation) EQ-5D index and PDQ-8 summary index (PDQ-8SI) scores were 0.76 (0.23) and 17.7 (14.2) at baseline and 0.52 (0.33) and 35.1 (17.4) at year four. Based on both ES and SRM indices, the rank order of responsiveness of the studied measures, from high to low, was PDQ-8SI (ES = 1.22), EQ-5D index score (ES = 1.06), H&Y score (ES = 0.82), and the EQ-VAS score (ES = 0.24).

CONCLUSION

Both the EQ-5D and PDQ-8 are responsive to changes in health burden of the Parkinson's disease over a 4-year period.

Comparative responsiveness of Parkinson's disease scales to change over time

The objective of the study is to examine the comparative responsiveness of outcome measures to assess progression over time in Parkinson's disease (PD). One hundred twenty-eight patients participating in a clinic-based naturalistic study of PD were assessed with the Hoehn and Yahr, UPDRS, MMSE, PDQ-39, PDQL, EQ-5D, and BDI scales at baseline and at 1 year. In addition, 82 patients in a community-based study of patients with PD who had completed self-rated Schwab and England, PDQ-39, EQ-5D, and BDI scales at baseline, were sent the same questionnaires at 1 and 4 years. Responsiveness was assessed using t-tests, standardised effect size, and standardised response mean. In both samples, the Hr-QoL measures were less responsive to change over time than the impairment and disability scales (Hoehn and Yahr, UPDRS, Schwab and England scales). In addition, in the clinic-based sample, Hoehn and Yahr and UPDRS ADL scale ("on") were more responsive to progression over time than UPDRS motor part and ADL part ("off"). Hr-QoL measures are less responsive to change over time than measures of impairment and disability. Although this suggests that these measures are less accurate in detecting subtle changes, it may also indicate that the multifactorial subjective assessment of Hr-QoL adapts to changes over time. Global assessment of overall impairment and disability (which incorporates motor and nonmotor features of PD), however, appeared relatively responsive to change over time in patients in a naturalistic setting.

Pharmacologic treatment of advanced Parkinson's disease: a meta-analysis of COMT inhibitors and MAO-B inhibitors

OBJECTIVE

To perform a meta-analysis of randomized placebo-controlled trials evaluating catechol-O-methyltransferase (COMT) inhibitors or monoamine oxidase type B (MAO-B) inhibitors in addition to levodopa versus levodopa alone for the treatment of advanced Parkinson's disease (PD).

METHODS

A systematic literature search was performed between 1990 and October 2007. The primary outcome measures assessed were the reduction in scores of Unified Parkinson's Disease Rating Scale (UPDRS) total, activities of daily living (ADL) and motor scores from baseline. Other efficacy and safety endpoints were also evaluated.

RESULTS

A total of 13 trials (n=3775 subjects) were included in the meta-analysis. As compared to placebo, COMT and MAO-B inhibitor use resulted in greater improvement in UPDRS total score (weighted mean difference [WMD] -2.13, 95%CI -0.46 to -0.20; and WMD -5.03, 95%CI -7.38 to -2.68) ADL scores (WMD -0.99, 95%CI -1.56 to -0.43; and WMD -1.48, 95%CI -2.13 to -0.83) and motor scores (WMD -1.50, 95%CI -2.70 to -0.30; and WMD -3.19, 95%CI -4.57 to -1.80) as well as increase in "on" time, reduction in "off" time and decreased need in levodopa dose compared to placebo. Incidences of dyskinesia were significantly higher with the COMT and MAO-B inhibitors compared to placebo.

CONCLUSION

The use of COMT or MAO-B inhibitors plus levodopa is superior to levodopa alone at reducing PD symptoms in patients with advanced PD. While combination therapies with COMT or MAO-B inhibitor plus levodopa seem especially useful amongst PD patients with wearing-off phenomenon, they are associated with more adverse events.

Impact of newer pharmacological treatments on quality of life in patients with Parkinson's disease

Parkinson's disease is a common progressive neurodegenerative condition with multiple motor and nonmotor features contributing to impairment of health-related quality of life (HR-QOL). Pharmacological treatments have been directed primarily at dopamine replacement with levodopa and agents to improve its bioavailability, including DOPA decarboxylase inhibitors, catechol-O-methyltransferase (COMT) inhibitors and monoamine oxidase B (MAO-B) inhibitors, as well as synthetic dopamine agonists. These treatments to restore motor function are often very successful in early Parkinson's disease, with objective improvement and concomitant improvement in subjective HR-QOL scores. However, as the disease progresses, motor complications and nonmotor symptoms predominate and are often refractory to therapeutic interventions. Antiparkinsonian medications have been shown to improve motor severity and motor complications of advancing disease, and there is increasing evidence that this can be translated into subjective improvement of HR-QOL from a patient's point of view. However, the degree of improvement is less marked on HR-QOL scores than on motor scores, and some studies do not show improvement of HR-QOL in parallel to motor improvements. A number of explanations are possible, including limitations of the scales used, trial designs and lack of clinical improvement from the patients' point of view. This review concentrates on clinical trials with an index of HR-QOL as an outcome measure, with particular emphasis on well designed, randomized, double-blind, placebo-controlled or active comparator-controlled methodology. Drugs that have been more recently added to the armamentarium of Parkinson's disease, including the oral (pramipexole, ropinirole and piribedil) and transdermal (rotigotine) non-ergotamine-derived dopamine agonists, the novel MAO-B inhibitor rasagiline and the COMT inhibitors tolcapone and entacapone, were included. The effect of each of these agents on overall HR-QOL and depression, a factor that has been shown to significantly contribute to HR-QOL in several multivariate analyses, is discussed.Overall, the literature search revealed 14 double-blind, placebo- or active comparator-controlled trials with an index of HR-QOL as an outcome measure. Entacapone resulted in HR-QOL improvement in nonfluctuating patients (one study) but not clearly in those with motor fluctuations (two studies). Tolcapone was only tested in patients with motor fluctuations and resulted in significant improvement in two of four studies using HR-QOL as an outcome measure. Rasagiline improved HR-QOL as monotherapy in early Parkinson's disease (one study), but not clearly in more advanced disease (one study). Rotigotine improved HR-QOL in both early Parkinson's disease (one study) and more advanced disease with motor fluctuations (one study). The impact of ropinirole and pramipexole on HR-QOL as monotherapy in early Parkinson's disease versus placebo has not been assessed, but both agents have resulted in improved HR-QOL in patients with motor fluctuations (ropinirole one study, pramipexole one study). The evidence for antidepressant efficacy of antiparkinsonian medications is limited.

Palliative Management of Parkinson Disease: Focus on Nonmotor, Distressing Symptoms

Parkinson disease is a progressive neurodegenerative disease that commonly affects elderly persons. In the absence of neuroprotective or curative therapies, currently available therapies only provide symptomatic benefit. Progression to advanced Parkinson disease is often accompanied by functional dependence with increased risk of admission to a long-term care facility. The prevalence of Parkinson disease in long-term care facilities, within the United States, has been estimated to be between 5.2% and 10%. Patients with advanced Parkinson disease also experience other distressing motor and nonmotor conditions, such as motor complications, dementia, depression, gastrointestinal distress, orthostatic hypotension, pain, and psychosis, which can be a challenge for clinicians to manage. The presence of distressing symptoms along with the fact that Parkinson disease remains incurable necessitate discussion on a palliative care approach to this disorder. This article discusses the symptomatic management of distressing symptoms encountered in the long-term care resident with Parkinson disease, including motor complications and nonmotor features.

Should levodopa dose be reduced when switched to stalevo?

The addition of entacapone to levodopa-carbidopa (LC) or the switch from LC to a tablet containing levodopa-carbidopa-entacapone (LCE) improves the wearing-off phenomenon, increases the 'on' time and decreases the 'off' time, but the appearance or exacerbation of dyskinesias is the more frequent side-effect. Thus, a reduction of the total levodopa dosage would be recommended. However, this could result in a lack of efficacy against the wearing-off. We report on the results of a clinical trial conducted to determine the best way in terms of efficacy, tolerability and safety of switching from LC to LCE in patients with Parkinson's disease (PD) and end of dose wearing-off. 39 patients with PD and wearing-off without or with mild dyskinesias were randomly assigned to either a group receiving the same LC dosage or to a group in which the total LC amount was reduced by 15-25%. Four weeks after the change, both groups showed an increase in daily 'on' time and a reduction in the daily time spent in 'off'. Two patients in each group experienced an increase in basal dyskinesias. No differences in clinical assessment between groups were found. Tolerance was excellent. This study suggests that switching from LC to LCE in patients with mild-to-moderate wearing-off can be done safely with or without reducing the total LD amount, but in the clinical setting it would be more practical to keep the dosage of LC unchanged unless severe dyskinesias are present.

The 39 item Parkinson's disease questionnaire (PDQ-39) revisited: implications for evidence based medicine

BACKGROUND

The 39 item Parkinson's disease questionnaire (PDQ-39) is the most widely used patient reported rating scale in Parkinson's disease. However, several fundamental measurement assumptions necessary for confident use and interpretation of the eight PDQ-39 scales have not been fully addressed.

METHODS

Postal survey PDQ-39 data from 202 people with Parkinson's disease (54% men; mean age 70 years) were analysed regarding psychometric properties using traditional and Rasch measurement methods.

RESULTS

Data quality was good (mean missing item responses, 2%) and there was general support for the legitimacy of summing items within scales without weighting or standardisation. Score reliabilities were adequate (Cronbach's alpha 0.72-0.95; test-retest 0.76-0.93). The validity of the current grouping of items into scales was not supported by scaling success rates (mean 56.2%), or factor and Rasch analyses. All scales represented more health problems than that experienced by the sample (mean floor effect 15%) and showed compromised score precision towards the less severe end.

CONCLUSIONS

Our results provide general support for the acceptability and reliability of the PDQ-39. However, they also demonstrate limitations that have implications for the use of the PDQ-39 in clinical research. The grouping of items into scales appears overly complex and the meaning of scale scores is unclear, which hampers their interpretation. Suboptimal targeting limits measurement precision and, therefore, probably also responsiveness. These observations have implications for the role of the PDQ-39 in clinical trials and evidence based medicine. PDQ-39 derived endpoints should be interpreted and selected cautiously, particularly regarding small but clinically important effects among people with less severe problems.

Scales in Parkinson's disease

The search for valid instruments to measure different domains of health disturbances becomes increasingly important for the assessment of Parkinson's disease. The most widely used tool is the Unified Parkinson's Disease Rating Scale (UPDRS) which was introduced in 1987 and is currently awaiting revision. In addition, a variety of instruments have been used to capture non-motor aspects of Parkinson's disease but only a minority of these instruments has been validated for this particular disease condition. Measurements of quality of life are being incorporated into an increasing number of studies in order to reflect a more integral view of health and have contributed to a better understanding of the impact of disease and interventions. The International Classification of Functioning, Disability and Health introduced by the WHO in 2001 offers a multidimensional approach to human functioning and participation that can also be applied to the assessment of health status in PD. This workshop report will focus on the present state of clinimetry in PD and discuss future perspectives.

Long-term effectiveness and quality of life improvement in entacapone-treated Parkinson's disease patients: the effects of an early therapeutic intervention

To evaluate the long-term effects of entacapone on both mean daily 'on' time and health-related quality of life (QoL) in patients with Parkinson's disease (PD) experiencing 'end-of-dose' motor fluctuations and the benefits of an early therapeutic intervention. A prospective, multicenter, observational, 12-month study was performed with an initial 3-month intervention phase, consisting of a phone call to half of the patients from randomly selected investigators to assess if dose adjustment was necessary. Effectiveness was determined by home diaries ('on' time), subscales II and III of the Unified Parkinson's Disease Rating Scale (UPDRS), and the Parkinson's Disease Questionnaire (PDQ-8). After 3 months of treatment, 4.0% of the intervention group patients discontinued the study, versus 18.4% in the control group (P < 0.01). The improvement in 'on' time was significantly increased since the 3-month visit (21%, P < 0.0001) until the end of the study (23% at 12 months, P < 0.0001). Entacapone also induced significant reductions in the UPDRS scores for subscales II and III and in the PDQ-8 score. 11.2% of patients experienced at least one adverse reaction. This study confirms the effectiveness of entacapone in reducing motor fluctuations by increasing 'on' time, and in improving QoL of PD patients. An early adjustment of entacapone and levodopa doses reduces the number of treatment discontinuations during the first months of treatment.

Self-reported health in people with Parkinson's disease left untreated at diagnosis

Early initiation of treatment in Parkinson's disease prevents patient‐reported deteriorations, but what is gained?

Effect of medical and surgical interventions on health-related quality of life in Parkinson's disease

Motor-related parameters are the standard outcome parameters for treatment interventions. Nonetheless, subjective appraisals about the consequences of treatment on health-related quality of life (HRQoL) are meanwhile established and may uncover important aspects of interventions. We have reviewed the literature with a defined search strategy and collected 61 clinical trials, which have used HRQoL as a planned outcome parameter. The articles were rated similarly as for the Task Force report of the Movement Disorder Society on interventions for Parkinson's disease (PD), but the relevant outcome parameter was HRQoL. We found that unilateral pallidotomy, deep brain stimulation of the subthalamic nucleus, and rasagiline are efficacious to improve the HRQoL of PD patients. For many other interventions, the efficacy to improve HRQoL in the PD setting cannot be considered to be proven so far. HRQoL should be part of future trial designs and more research is necessary to understand the determinants of QoL in PD.

Balancing short-term symptom control and long-term functional outcomes in patients with Parkinson's disease

Levodopa has played a central role in the treatment of Parkinson's disease for nearly 40 years and remains the single most effective symptomatic treatment for the disease. However, the response to levodopa therapy changes over time, and its long-term use is commonly associated with disabling motor complications. For this reason, the appropriate role of levodopa in the treatment of Parkinson's disease-in particular, the question of when to initiate therapy with the drug-has been a matter of controversy. Because levodopa is the most effective treatment for Parkinson's disease, the management of this disease becomes a matter of balancing short-term symptom control with long-term functional outcomes. This article provides an overview of the basis for levodopa-associated motor complications and their impact on patients' clinical function and quality of life, followed by a discussion of strategies for managing these complications to achieve optimum symptom control while minimizing the adverse effects of long-term therapy.

Quality of life and related concepts in Parkinson's disease: A systematic review

Several studies have investigated the quality of life (QOL) of patients with Parkinson's disease (PD). The purpose of this study was to review the conceptual and methodological quality of quality of life (QOL) studies among patients with PD and to identify factors associated with poor (HR)QOL. Computerized bibliographic databases were screened for publications from 1960 to January 2007. According to a list of predefined criteria, the methodological quality of the 61 studies, was moderate. The term 'QOL' was often used inappropriately. In fact, almost all studies in this review actually assessed health status (HS) instead of QOL. The functioning of patients with PD on physical, social, and emotional domains is affected by PD. Their HS seems to be lower when compared to healthy persons or patients with other chronic diseases. HS studies augment the insight in self-perceived functioning. Therefore, HS is conceived as a valuable construct. However, QOL is also an important factor in health care. Attention towards QOL is needed in order to draw valid conclusions regarding a person's subjective experience of well-being in a broad sense. In order to accomplish this, future studies should apply the QOL concept with more rigor, should use an adequate operational definition, and should employ sound measures.

A randomized trial of deep-brain stimulation for Parkinson's disease

BACKGROUND

Neurostimulation of the subthalamic nucleus reduces levodopa-related motor complications in advanced Parkinson's disease. We compared this treatment plus medication with medical management.

METHODS

In this randomized-pairs trial, we enrolled 156 patients with advanced Parkinson's disease and severe motor symptoms. The primary end points were the changes from baseline to six months in the quality of life, as assessed by the Parkinson's Disease Questionnaire (PDQ-39), and the severity of symptoms without medication, according to the Unified Parkinson's Disease Rating Scale, part III (UPDRS-III).

RESULTS

Pairwise comparisons showed that neurostimulation, as compared with medication alone, caused greater improvements from baseline to six months in the PDQ-39 (50 of 78 pairs, P=0.02) and the UPDRS-III (55 of 78, P<0.001), with mean improvements of 9.5 and 19.6 points, respectively. Neurostimulation resulted in improvements of 24 to 38 percent in the PDQ-39 subscales for mobility, activities of daily living, emotional well-being, stigma, and bodily discomfort. Serious adverse events were more common with neurostimulation than with medication alone (13 percent vs. 4 percent, P<0.04) and included a fatal intracerebral hemorrhage. The overall frequency of adverse events was higher in the medication group (64 percent vs. 50 percent, P=0.08).

CONCLUSIONS

In this six-month study of patients under 75 years of age with severe motor complications of Parkinson's disease, neurostimulation of the subthalamic nucleus was more effective than medical management alone. (ClinicalTrials.gov number, NCT00196911 [ClinicalTrials.gov].).

Assessment of subjective health and health-related quality of life in persons with acquired or degenerative brain injury

PURPOSE OF REVIEW

Health-related quality of life is a new outcome variable in neurology. Several generic measures aim at assessing this variable in adults with neurological diseases. Disease-specific measures are still rare; however, individuals with neurological diseases frequently suffer from cognitive impairment, yet are often excluded from health-related quality of life investigations. When included in such studies, cognitive functioning is not monitored via neuropsychological evaluation, possibly leading to methodological problems. Papers from May 2004 until July 2005 are reviewed with respect to psychometric quality and information about persons after traumatic brain injury, stroke, Parkinson's disease or dementia.

RECENT FINDINGS

Several new cross-sectional and longitudinal outcome studies are reviewed. The Medical Outcome Study Short Form with 36 items, the Sickness Impact Profile and the Nottingham Health Profile were identified as the most frequently used measures in neurology. For traumatic brain injury, two new generic instrument validations (Life Satisfaction Index-A, Subjective Quality of Life Profile) and one internationally validated disease-specific development (Quality of Life after Brain Injury) were found; for stroke, one disease-specific tool (Burden of Stroke Scale) was identified. In Parkinson's disease, the disease-specific health-related quality of life measure Parkinson's Disease Questionnaire-39 is well validated. In dementia, three dementia-specific instruments (Quality of Life for Dementia, Quality of Life in Late-Stage Dementia Scale and Quality of Life in Alzheimer's Disease Scale) seem to be valid.

SUMMARY

In neurology, only a few measures have been developed and validated for respondents with cognitive impairment, often showing poorer validity results than studies involving healthy persons. Health-related quality of life assessment should therefore be validated in the specific diseases and, if necessary, combined with a neuropsychological evaluation and a disease-specific health-related quality of life measure.

Entacapone in the treatment of Parkinson's disease

BACKGROUND

The development of fluctuations in motor response and involuntary movements commonly complicate the treatment of Parkinson's disease (PD). Catechol-O-methyltransferase (COMT) inhibitors delay the breakdown of levodopa, which leads to an increase in levodopa bioavailability and more stable concentrations of plasma levodopa. The addition of a COMT inhibitor therefore combines the rapid onset of levodopa with prolonged efficacy, and theoretically provides a more continuous stimulation of dopamine receptors with reduced risk of motor complications. Randomised, controlled trials have shown that in patients with PD who have motor fluctuations, the addition of the COMT-inhibitor entacapone results in an improvement in motor fluctuations, particularly of the "wearing-off" type, with about 1.0-1.7 h more on-time and less off-time per day, reduced required levodopa dose, modest improvement in motor and disability scores (mean total unified PD rating scale [UPDRS] scores of about 4.5), and in some but not all studies improvement of health-related quality of life [HRQOL] scores.

RECENT DEVELOPMENTS

Patients with stable PD, without motor fluctuations, also have improved HRQOL scores on treatment with entacapone in addition to levodopa with a dopa-decarboxylase inhibitor. However, in a recent large multicentre study, UPDRS motor and disability scores were not improved despite significant improvements in HRQOL scores. The disparity between results on clinical rating scales and HRQOL scores suggests that these scales give different and potentially complementary information on health status changes in PD, and that entacapone provides benefit that may not be captured with standard clinical rating scales. Whether entacapone combined with levodopa can delay dyskinesia or motor fluctuations in patients with untreated PD is unknown; however, in animal studies, a decrease in motor complications has been reported in drug-naive animals given frequent doses of levodopa combined with entacapone. WHERE NEXT?: Clinical studies are underway to address the hypothesis that motor complications in PD can be delayed if entacapone is given from the start of treatment. Until the results of these trials are available, entacapone is indicated as a useful adjunct to levodopa in the symptomatic treatment of patients with PD with and without motor fluctuations. In addition, future trials should specifically assess the effect of entacapone on HRQOL in PD.