Nonmotor symptoms of Parkinson’s disease

Nonmotor symptoms occur commonly in Parkinson's disease (PD) patients and are frequently under-recognized and undertreated. Symptoms include sleep abnormalities, fatigue, autonomic disturbances, mood disorders and cognitive dysfunction. Early recognition and treatment of nonmotor symptoms in PD is critical to providing optimal management. A new screening questionnaire and the revised Unified PD Rating Scale should assist healthcare providers to better identify and evaluate these symptoms. This article reviews the identification and treatment of nonmotor symptoms in PD.

Clinical utility of dopamine transporter single photon emission CT (DaT-SPECT) with (123I) ioflupane in diagnosis of parkinsonian syndromes

The diagnosis of movement disorders including Parkinson's disease (PD) and essential tremor is determined through clinical assessment. The difficulty with diagnosis of early PD has been highlighted in several recent clinical trials. Studies have suggested relatively high clinical diagnostic error rates for PD and essential tremor. This review was undertaken to clarify the utility of DaT-SPECT imaging with ((123)I)ioflupane (DaTSCAN or DaTscan or ((123)I)FP-CIT) in assisting practitioners in their clinical decision making by visualising the dopamine transporter in parkinsonian cases. In some patients with suspected parkinsonian syndromes, SPECT imaging with ((123)I)ioflupane is useful to assist in the diagnosis and to help guide prognosis and treatment decisions, including avoiding medications that are unlikely to provide benefit. Clinicians ordering ((123)I)ioflupane SPECT should be aware of its limitations and pitfalls and should order scans when there is diagnostic uncertainty or when the scan will be helpful in clinical decision making.

Randomized trial of cognitive speed of processing training in Parkinson disease

OBJECTIVE

To examine the efficacy of cognitive speed of processing training (SOPT) among individuals with Parkinson disease (PD). Moderators of SOPT were also examined.

METHODS

Eighty-seven adults, 40 years of age or older, with a diagnosis of idiopathic PD in Hoehn & Yahr stages 1-3 and on a stable medication regimen were randomized to either 20 hours of self-administered SOPT (using InSight software) or a no-contact control condition. Participants were assessed at baseline and after 3 months of training (or an equivalent delay). The primary outcome measure was useful field of view test (UFOV) performance, and secondary outcomes included cognitive self-perceptions and depressive symptoms.

RESULTS

Results indicated that participants randomized to SOPT experienced significantly greater improvements on UFOV performance relative to controls, Wilks λ = 0.938, F 1,72 = 4.79, p = 0.032, partial η(2) = 0.062. Findings indicated no significant effect of training on secondary outcomes, Wilks λ = 0.987, F2,70 < 1, p = 0.637, partial η(2) = 0.013.

CONCLUSIONS

Patients with mild to moderate stage PD can self-administer SOPT and improve their cognitive speed of processing, as indexed by UFOV (a robust predictor of driving performance in aging and PD). Further research should establish if persons with PD experience longitudinal benefits of such training and if improvements translate to benefits in functional activities such as driving.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that SOPT improves UFOV performance among persons in the mild to moderate stages of PD.

AFQ056 in Parkinson patients with levodopa-induced dyskinesia: 13-week, randomized, dose-finding study

AFQ056 is a novel, selective metabotropic glutamate receptor 5 antagonist. This was a 13-week, double-blind, placebo-controlled study. Patients with Parkinson's disease and moderate-to-severe levodopa (l-dopa)-induced dyskinesia who were receiving stable l-dopa/anti-parkinsonian treatment and were not currently receiving amantadine were randomized to receive either AFQ056 (at doses of 20, 50, 100, 150, or 200 mg daily) or placebo (1:1:1:1:2:3 ratio) for 12 weeks. The primary outcome was the modified Abnormal Involuntary Movements Scale. Secondary outcomes included the 26-item Parkinson's Disease Dyskinesia Scale, the Patient's/Clinician's Global Impression of Change, and the Unified Parkinson's Disease Rating Scale parts III (motor evaluation) and IV (severity of motor complications). Safety was assessed. In total, 98 of 133 (73.7%) AFQ056-treated patients and 47 of 64 (73.4%) patients in the placebo group completed the study. Baseline characteristics were comparable. Patients randomized to AFQ056 200 mg daily administered in 2 doses demonstrated significant improvements at Week 12 on the modified Abnormal Involuntary Movements Scale compared with placebo (difference, -2.8; 95% confidence interval [CI], -5.2, -0.4; P = 0.007). Based on final actual doses, there was a dose-response relationship on the modified Abnormal Involuntary Movements Scale, with 200 mg daily demonstrating the most robust effect (difference, -3.6; 95% CI, -7.0, -0.3; P = 0.012). Improvements in dyskinesia were supported by change on Unified Parkinson's Disease Rating Scale part IV item 32 (50 mg daily: difference, -0.7; 95% CI, -1.1, -0.2; P = 0.003; 200 mg daily: difference, -0.5; 95% CI, -0.8, -0.1; P = 0.005). No significant changes were observed on the 26-item Parkinson's Disease Dyskinesia Scale, the Unified Parkinson's Disease Rating Scale part IV item 33 or items 32 and 33, or the Patient's/Clinician's Global Impression of Change. Unified Parkinson's Disease Rating Scale part III scores were not significantly changed, indicating no worsening of motor symptoms. The most common adverse events (with incidence greater with AFQ056 than with placebo) were dizziness, hallucination, fatigue, nasopharyngitis, diarrhea, and insomnia. AFQ056 demonstrated anti-dyskinetic efficacy in this population without worsening underlying motor symptoms. These results will guide dose selection for future clinical trials.

Long-term safety and efficacy of preladenant in subjects with fluctuating Parkinson's disease

BACKGROUND

Preladenant is a selective adenosine A₂A receptor antagonist under investigation for Parkinson's disease treatment.

METHODS

A phase 2 36-week open-label follow-up of a double-blind study using preladenant 5 mg twice a day as a levodopa adjunct in 140 subjects with fluctuating Parkinson's disease was conducted. The primary end point was adverse event (AE) assessment. Secondary (efficacy) analyses included hours/day spent in OFF and ON states and dyskinesia prevalence/severity.

RESULTS

The 36-week open-label phase was completed by 106 of 140 subjects (76%). AE-related treatment discontinuations occurred in 19 subjects (14%). Treatment-emergent AEs, reported by ≥15% of subjects, were dyskinesia (33%) and constipation (19%). Preladenant 5 mg twice a day provided OFF time reductions (1.4-1.9 hours/day) and ON time increases (1.2-1.5 hours/day) throughout the 36-week treatment relative to the baseline of the double-blind study.

CONCLUSIONS

Long-term preladenant treatment (5 mg twice a day) was generally well tolerated and provided sustained OFF time reductions and ON time increases.

Clinical trials of add-on medications in Parkinson's disease: Efficacy versus usefulness

Clinical trials designed to evaluate the efficacy of new anti-parkinsonian agents often employ an 'add-on' protocol in which patients with motor fluctuations on levodopa are randomized to receive active medication or placebo. Levodopa doses may not be increased, but can be decreased in response to dopaminergic side-effects such as increasing dyskinesia or hallucinations. Although these trials can delineate efficacy, additional studies are necessary to evaluate the usefulness of these medications in the clinical setting. The most important questions to be answered by such studies are: (1) Is the benefit derived from addon medication greater than that which could be brought about by further levodopa titration alone?, and (2) Can 'off' time be decreased and motor function improved without a proportionate increase in unwanted dyskinesia? The short-term symptomatic usefulness of an add-on medication can be evaluated by comparing the effects of the addition of active medication plus levodopa titration to further levodopa titration alone. We discuss the limitations of current add-on protocols as well as protocols which may help address the issue of clinical usefulness.

AbobotulinumtoxinA (Dysport) dosing in cervical dystonia: an exploratory analysis of two large open-label extension studies

Treatment with botulinum toxin-A is recommended as first-line treatment for cervical dystonia (CD). In clinical practice many factors appear to influence dose adjustment and the retreatment regimen; however, there is little information available in the literature regarding the evolution of dosing over treatment cycles. We report on two similarly designed, long-term, multicenter, open-label extension studies of Dysport for the treatment of CD, which followed 500 U fixed-dose placebo-controlled trials. Both studies specified a fixed 500 U dose for the first open-label treatment cycle, with dose adjustment in subsequent treatment cycles according to the clinical response. These analyses include 218 patients who entered the two studies; doses in the subsequent treatment cycles ranged between 250 and 1,000 U. During open-label treatment, all treatment cycles resulted in improvements in mean Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total scores. However, increasing the dose of Dysport above the initial 500 U dose was not observed to result in an incremental improvement in response as measured by the TWSTRS. No individual patient characteristic was found to reliably predict the use of higher doses at each treatment cycle. Dysport was generally well tolerated with no major differences in the incidence of adverse events (AEs) observed with different doses. Dysphagia was considered an AE of special interest and dysphagia data from the open-label studies were combined with two Phase II studies. Analysis of this enhanced database indicates that unilateral injections of >150 U into the sternocleidomastoid muscle is associated with a higher dysphagia risk. Thus, limiting the dose in the sternocleidomastoid may help reduce the incidence of dysphagia.

Future treatments for Parkinson's disease: surfing the PD pipeline

Our current wish list for the treatment of Parkinson's disease (PD) includes therapies that will provide robust and sustained antiparkinsonian benefit through the day, ameliorate or prevent dyskinesia, and slow or prevent the progression of the disease. In this article, I review selected new therapies in clinical development for motor features or treatment complications of PD, and some that may slow disease progression. These include adenosine 2a (A2a) antagonists (istradefylline, preladenant, and SYN115), levodopa/carbidopa intestinal gel (LCIG), IPX066--an extended-release formulation of carbidopa/levodopa, XP21279--a sustained-release levodopa prodrug, ND0611--a carbidopa subcutaneous patch, safinamide--a mixed mechanism of action medication that may provide both MAO-B and glutamate inhibition, PMY50028--an oral neurotrophic factor inducer, antidyskinesia medications (AFQ056 and fipamezole), and gene therapies (AAV2-neurturin and glutamic acid decarboxylase gene transfer). Some of these therapies will never be proven efficacious and will not come to market while others may play a key role in the future treatment of PD.

Success rate, efficacy, and safety/tolerability of overnight switching from immediate- to extended-release pramipexole in advanced Parkinson's disease

BACKGROUND AND PURPOSE

For Parkinson's disease (PD), an extended-release (ER) pramipexole formulation taken once daily, has shown efficacy, safety, and tolerability resembling those of immediate-release (IR) pramipexole taken three times daily. The present study assessed, in advanced PD, the success of an overnight switch from adjunctive IR to ER.

METHODS

Levodopa users experiencing motor fluctuations were randomized to adjunctive double-blind (DB) placebo, IR, or ER. Amongst completers of ≥18 weeks, ER recipients were kept on DB ER, whilst IR recipients were switched overnight to DB ER at unchanged daily dosage. After a DB week, switch success was assessed. During the next 5 weeks, all patients underwent ER titration to optimal open-label maintenance dosage.

RESULTS

One week post-switch, 86.2% of 123 IR-to-ER and 83.8% of 105 ER-to-ER patients had ≤15% (or ≤3-point, for pre-switch scores ≤20) increase on UPDRS Parts II + III, and 77.9% (of 122) and 70.2% (of 104) had ≤1-h increase in daily OFF-time. At 32 weeks, the groups showed comparable improvements from DB baseline (pramipexole inception), including, on UPDRS II + III, adjusted mean (SE) changes of -14.8 (1.5) for IR-to-ER and -13.3 (1.6) for ER-to-ER. Rates of premature discontinuation owing to adverse events were 6.5% for IR-to-ER and 4.9% for ER-to-ER.

CONCLUSIONS

By OFF-time and UPDRS criteria, majorities of patients with advanced PD were successfully switched overnight from pramipexole IR to ER at unchanged daily dosage. During subsequent maintenance, pramipexole showed sustained efficacy, safety, and tolerability, regardless of formulation (IR or ER) in the preceding DB trial.

Randomized clinical trial of fipamezole for dyskinesia in Parkinson disease (FJORD study)

OBJECTIVE

Fipamezole, a selective α2-adrenergic receptor antagonist, reduced levodopa-induced dyskinesias (LID) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned monkeys. In 10 dyskinetic subjects with Parkinson disease (PD), a proof-of-concept study showed beneficial effects at single doses of 60 and 90 mg. The primary study objective was to assess suppression of LID by fipamezole at day 28, as measured by the levodopa-induced dyskinesia scale (LIDS), a modification of the abnormal involuntary movement scale.

METHODS

This was a double-blind, randomized, placebo-controlled, dose-escalating 28-day study in levodopa-treated patients with PD experiencing LID, conducted at 25 centers in the United States (115 subjects) and 7 centers in India (64 subjects). Dyskinesias were evaluated 3 times after subjects became "on" from levodopa. Outcome assessment was performed with analysis of variance, which evaluated fipamezole dose-effects in a hierarchical stepwise manner and the Jonckheere test for dose responsiveness.

RESULTS

The total study population showed no statistically significant primary endpoint difference. However, because of inhomogeneity recognized between U.S. and Indian study populations, a prespecified subgroup analysis of U.S. subjects was conducted, showing fipamezole at 90 mg reduced LID (mean, 95% CI, LID rating improvement vs placebo -1.9 [0.0 to -3.8; p = 0.047]). Dose responsiveness was demonstrated (p = 0.014 for placebo, 30, 60, and 90 mg fipamezole). Fipamezole induced mild, transient blood pressure elevation and was associated with an acceptable profile of adverse effects.

CONCLUSIONS

The evidence of efficacy in the US subgroup suggested that fipamezole at 90 mg TID may be useful to treat LID in PD without exacerbating parkinsonism.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that fipamezole is well-tolerated and, in the US subpopulation, lessens LID at 90 mg TID.

A(2A) Receptor Antagonism and Dyskinesia in Parkinson's Disease

Dyskinesia, a major complication of treatment of Parkinson's disease (PD), involves two phases: induction, which is responsible for dyskinesia onset, and expression, which underlies its clinical manifestation. The unique cellular and regional distribution of adenosine A(2A) receptors in basal ganglia areas that are richly innervated by dopamine, and their antagonistic role towards dopamine receptor stimulation, have positioned A(2A) receptor antagonists as an attractive nondopaminergic target to improve the motor deficits that characterize PD. In this paper, we describe the biochemical characteristics of A(2A) receptors and the effects of adenosine A(2A) antagonists in rodent and primate models of PD on L-DOPA-induced dyskinesia, together with relevant biomarker studies. We also review clinical trials of A(2A) antagonists as adjuncts to L-DOPA in PD patients with motor fluctuations. These studies have generally demonstrated that the addition of an A(2A) antagonist to a stable L-DOPA regimen reduces OFF time and mildly increases dyskinesia. However, limited clinical data suggest that the addition of an A(2A) antagonist along with a reduction of L-DOPA might maintain anti-Parkinsonian benefit and reduce dyskinesia. Whether A(2A) antagonists might reduce the development of dyskinesia has not yet been tested clinically.

Head injury, α-synuclein Rep1, and Parkinson's disease

OBJECTIVE

To test the hypothesis that variability in SNCA Rep1, a polymorphic dinucleotide microsatellite in the promoter region of the gene encoding α-synuclein, modifies the association between head injury and Parkinson's disease (PD) risk.

METHODS

Participants in the Farming and Movement Evaluation (FAME) and the Study of Environmental Association and Risk of Parkinsonism using Case-Control Historical Interviews (SEARCH), 2 independent case-control studies, were genotyped for Rep1 and interviewed regarding head injuries with loss of consciousness or concussion prior to Parkinson's disease (PD) diagnosis. Logistic regression modeling adjusted for potential confounding variables and tested interaction between Rep1 genotype and head injury.

RESULTS

Consistent with prior reports, relative to medium-length Rep1, short Rep1 genotype was associated with reduced PD risk (pooled odds ratio [OR], 0.7; 95% confidence interval [CI], 0.5-0.9), and long Rep1 with increased risk (pooled OR, 1.4; 95% CI, 0.95-2.2). Overall, head injury was not significantly associated with PD (pooled OR, 1.3; 95% CI, 0.9-1.8). However, head injury was strongly associated with PD in those with long Rep1 (FAME OR, 5.4; 95% CI, 1.5-19; SEARCH OR, 2.3; 95% CI, 0.6-9.2; pooled OR, 3.5; 95% CI 1.4-9.2, p-interaction = 0.02). Individuals with both head injury and long Rep1 were diagnosed 4.9 years earlier than those with neither risk factor (p = 0.03).

INTERPRETATION

While head injury alone was not associated with PD risk, our data suggest head injury may initiate and/or accelerate neurodegeneration when levels of synuclein are high, as in those with Rep1 expansion. Given the high population frequency of head injury, independent verification of these results is essential.

The UPDRS-8: a brief clinical assessment scale for Parkinson's disease

We evaluated a brief, 8-item version of the Unified Parkinson's Disease Rating Scale (UPDRS) using two existing patient databases. One database included 1,445 PD patients. Spearman correlation between UPDRS-8 motor scores and full UPDRS motor scores was .765 (p < .001). Correlation between total UPDRS-8 scores and full UPDRS total scores (parts I-III) was .798 (p < .001). Correlation between total UPDRS-8 scores and total 39-item PD questionnaire (PDQ-39) scores was .629 (p < .001). In 177 patients undergoing deep brain stimulation (DBS), UPDRS-8 motor scores were similarly significantly sensitive to change as full UPDRS motor scores in assessing change from the medication OFF state to the medication ON state at baseline and from the medication OFF state at baseline to the medication OFF/stimulation ON state 1 year post-DBS. The UPDRS-8 focuses on items that are most relevant for clinical decision making. In this study, the UPDRS-8 exhibited good correlation with the full UPDRS and the PDQ-39. We therefore believe that it can provide a useful, rapid assessment of PD patients in clinical practice. Whether it might be useful in clinical trials depends on demonstrating that it is also sensitive to relatively small changes in clinical status.

Pardoprunox as adjunct therapy to levodopa in patients with Parkinson's disease experiencing motor fluctuations: results of a double-blind, randomized, placebo-controlled, trial

AIMS

To determine the efficacy and safety of pardoprunox in levodopa-treated patients with Parkinson's disease (PD) experiencing motor fluctuations.

METHODS

Patients were randomized to pardoprunox (up to 42 mg/day, n = 150) or placebo (n = 144). Pardoprunox was titrated to an optimal dose over 7 weeks, followed by a 12-week stable dose period. The primary efficacy variable was the change from baseline to study endpoint in total daily OFF time, based on patient diaries. Secondary analyses included the change in ON time without troublesome dyskinesias, UPDRS-ADL + Motor ON, UPDRS-ADL OFF and PDQ-39. Subgroup analyses explored the impact of pardoprunox on dyskinesias (UPDRS items 32 + 33), depression (Hospital Anxiety Depression Scale) and pain (Visual Analogue Scale).

RESULTS

Pardoprunox significantly reduced OFF time versus placebo (-1.62 h/day versus -0.92 h/day, respectively, p = 0.0215). Compared to placebo, pardoprunox improved ON time without troublesome dyskinesias (p = 0.0386), UPDRS-ADL + Motor ON (p = 0.0003), and UPDRS-ADL OFF (p < 0.0001), while no significant difference was observed on PDQ-39. A high drop-out rate due to adverse events (AEs) (pardoprunox, 37%; placebo, 12%) suggested that the selected dose range may have been too high, and/or titration was too rapid.

CONCLUSIONS

Pardoprunox decreased OFF time and increased ON time without troublesome dyskinesias in levodopa-treated PD patients. The high drop-out rate at the selected doses justifies the investigation of lower doses. The impact of pardoprunox on dyskinesias and non-motor symptoms deserves further investigation.

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.

Extended-release pramipexole in advanced Parkinson disease: a randomized controlled trial

BACKGROUND

In advanced Parkinson disease (PD), immediate-release pramipexole, taken 3 times daily, improves symptoms and quality of life. A once-daily extended-release formulation may be an effective and simple alternative therapy.

METHODS

For a multicenter randomized, double-blind, parallel trial of extended- and immediate-release pramipexole vs placebo, patients experiencing motor fluctuations while taking levodopa underwent flexible study drug titration and then maintenance at optimized dosage (0.375-4.5 mg/day). The primary endpoint was a change in the Unified Parkinson's Disease Rating Scale (UPDRS) part II+III score at 18 weeks, with further assessments at 33 weeks in a subset of patients. Adverse events were recorded throughout.

RESULTS

Among 507 patients in the 18-week analyses, UPDRS II+III scores decreased (from baseline means of 40.0-41.7) by an adjusted mean of -11.0 for extended-release pramipexole and -12.8 for immediate-release pramipexole vs -6.1 for placebo (p = 0.0001 and p < 0.0001) and off-time decreased (from baseline means of 5.8-6.0 hours/day) by an adjusted mean of -2.1 and -2.5 vs -1.4 hours/day (p = 0.0199 and p < 0.0001). Other outcomes were largely corroborative, including a significant improvement in early morning off symptoms. Among 249 pramipexole patients completing 33 weeks, UPDRS II+III and off-time findings showed ≤10.1% change from 18-week values. Both formulations were well-tolerated.

CONCLUSIONS

Extended-release pramipexole significantly improved UPDRS score and off-time compared with placebo, with similar efficacy, tolerability, and safety of immediate-release pramipexole compared with placebo.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that the extended-release form of pramipexole, taken once daily, is efficacious as an adjunct to levodopa in advanced PD.

Extended-release pramipexole in early Parkinson disease: a 33-week randomized controlled trial

OBJECTIVE

To assess the clinical efficacy of a novel once-daily extended-release (ER) formulation of the dopamine agonist pramipexole as monotherapy in patients with early Parkinson disease (PD) and establish its noninferiority vs standard immediate-release (IR) pramipexole.

METHODS

This was a multicenter, double-blind, parallel study of patients with early PD not receiving levodopa or dopamine agonists, randomly assigned to pramipexole IR, pramipexole ER, or placebo. Seven-week flexible titration was followed by 26-week maintenance, with levodopa permitted as rescue medication. The primary analysis was to test pramipexole ER noninferiority to pramipexole IR based on a change in the Unified Parkinson's Disease Rating Scale (UPDRS) part II+III score at 33 weeks, with noninferiority predefined as a treatment group difference for which the lower bound of the 95% confidence interval (CI) did not exceed -3 points.

RESULTS

Among 213 ER and 207 IR recipients, the adjusted mean 33-week UPDRS II+III change (excluding levodopa rescue effects) was -8.2 for ER and -8.7 for IR, a difference of -0.5 with a 95% CI of -2.3 to 1.3. Compared with placebo (n = 103), pramipexole ER and pramipexole IR were significantly superior on UPDRS II+III score, all key secondary outcomes, and almost all other endpoints. On the 39-item Parkinson Disease Questionnaire, superiority of pramipexole ER failed to reach statistical significance. Both formulations were equally safe and well-tolerated.

CONCLUSIONS

As monotherapy for early PD, pramipexole ER was noninferior to pramipexole IR and significantly more effective than placebo. Tolerability and safety did not differ between the formulations.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that pramipexole ER is not inferior to pramipexole IR in patients with early PD.

Clinical vignettes in Parkinson's disease: a collection of unusual medication-induced hallucinations, delusions, and compulsive behaviours

Hallucinations, delusions, and compulsive behaviors are frequent iatrogenic complications of the treatment of motor dysfunction in Parkinson's disease (PD). Although these have been studied, and the phenomenology described, there are few detailed descriptions of the various psychiatric problems our treated PD patients live with that allow physicians who do not have a great deal of experience with PD patients to appreciate the extent of their altered lives. This report is a compilation of vignettes describing these behavioral problems that the treating neurologist or psychiatrist attributed to the medications used for treating PD.