Cortical response to levodopa in Parkinson's disease patients with dyskinesias

Levodopa‐induced dyskinesias are a common and disabling side effect of dopaminergic therapy in Parkinson's disease, but their neural mechanisms in vivo are still poorly understood. Besides striatal pathology, the importance of cortical dysfunction has been increasingly recognized. The supplementary motor area in particular, may have a relevant role in dyskinesias onset given its involvement in endogenously generated actions. The aim of the present study was to investigate the levodopa‐related cortical excitability changes along with the emergence of levodopa‐induced peak‐of‐dose dyskinesias in subjects with Parkinson's disease. Thirteen patients without dyskinesias and ten with dyskinesias received 200/50 mg fast‐acting oral levodopa/benserazide following overnight withdrawal (12 hr) from their dopaminergic medication. We targeted transcranial magnetic stimulation to the supplementary motor area, ipsilateral to the most dopamine‐depleted striatum defined with single‐photon emission computed tomography with [¹²³I]N‐ω‐fluoropropyl‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)nortropane, and recorded transcranial magnetic stimulation‐evoked potentials with high‐density electroencephalography before and at 30, 60, and 180 min after levodopa/benserazide intake. Clinical improvement from levodopa/benserazide paralleled the increase in cortical excitability in both groups. Subjects with dyskinesias showed higher fluctuation of cortical excitability in comparison to non‐dyskinetic patients, possibly reflecting dyskinetic movements. Together with endogenous brain oscillation, levodopa‐related dynamics of brain state could influence the therapeutic response of neuromodulatory interventions.     

AFQ056 treatment of levodopa‐induced dyskinesias: Results of 2 randomized controlled trials

Study objectives were to assess the efficacy, safety, and tolerability of AFQ056 in Parkinson's disease patients with levodopa‐induced dyskinesia. Two randomized, double‐blind, placebo‐controlled, parallel‐group, in‐patient studies for Parkinson's disease patients with moderate to severe levodopa‐induced dyskinesia (study 1) and severe levodopa‐induced dyskinesia (study 2) on stable dopaminergic therapy were performed. Patients received 25–150 mg AFQ056 or placebo twice daily for 16 days (both studies). Study 2 included a 4‐day down‐titration. Primary outcomes were the Lang‐Fahn Activities of Daily Living Dyskinesia Scale (study 1), the modified Abnormal Involuntary Movement Scale (study 2), and the Unified Parkinson's Disease Rating Scale–part III (both studies). Secondary outcomes included the Unified Parkinson's Disease Rating Scale–part IV items 32–33. The primary analysis was change from baseline to day 16 on all outcomes. Treatment differences were assessed. Fifteen patients were randomized to AFQ056 and 16 to placebo in study 1; 14 patients were randomized to each group in study 2. AFQ056‐treated patients showed significant improvements in dyskinesias on day 16 versus placebo (eg, Lang‐Fahn Activities of Daily Living Dyskinesia Scale, P = .021 [study 1]; modified Abnormal Involuntary Movement Scale, P = .032 [study 2]). No significant changes were seen from baseline on day 16 on the Unified Parkinson's Disease Rating Scale‐part III in either study. Adverse events were reported in both studies, including dizziness. Serious adverse events (most commonly worsening of dyskinesias, apparently associated with stopping treatment) were reported by 4 AFQ056‐treated patients in study 1, and 3 patients (2 AFQ056‐treated patient and 1 in the placebo group) in study 2. AFQ056 showed a clinically relevant and significant antidyskinetic effect without changing the antiparkinsonian effects of dopaminergic therapy. © 2011 Movement Disorder Society     

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. © 2013 International Parkinson and Movement Disorder Society     

Effects of DBS,premotor rTMS,and levodopa on motor function and silent period in advanced Parkinson's disease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used and highly effective treatment for patients with advanced Parkinson's disease (PD). Repetitive TMS (rTMS) applied to motor cortical areas has also been shown to improve symptoms in PD and modulate motor cortical excitability. Here, we compared clinical and neurophysiological effects of STN stimulation with those of 1 Hz rTMS given to the dorsal premotor cortex (PMd) and those following intake of levodopa in a group of PD patients with advanced disease. Ten PD patients were studied on 2 consecutive days before and after surgery. Clinical effects were determined using the UPDRS motor score. Motor thresholds, motor‐evoked potential (MEP) amplitudes during slight voluntary contraction, and the cortical silent periods (SP) were measured using TMS. Before surgery effects of levodopa and 1 Hz PMd rTMS and after surgery those of STN stimulation with or without additional levodopa were determined. Levodopa significantly improved clinical symptoms and increased the SP duration. STN stimulation improved clinical symptoms without changing the SP duration. In contrast, 1 Hz PMd rTMS was not effective clinically but normalized the SP duration. Whereas levodopa had widespread effects at different levels of an abnormally active motor network in PD, STN stimulation and PMd rTMS led to either clinical improvement or SP normalization, i.e., only partially reversed abnormal motor network activity. © 2009 Movement Disorder Society     

Onset of dyskinesia with adjunct ropinirole prolonged‐release or additional levodopa in early Parkinson's disease

Levodopa‐induced dyskinesia can result in significant functional disability and reduced quality of life in patients with Parkinson's disease (PD). The goal of this study was to determine if the addition of once‐daily ropinirole 24‐hour prolonged‐release (n = 104) in PD patients not optimally controlled with levodopa after up to 3 years of therapy with less than 600 mg/d delays the onset of dyskinesia compared with increasing doses of levodopa (n = 104). During the study, 3% of the ropinirole prolonged‐release group (mean dose 10 mg/d) and 17% of the levodopa group (mean additional dose 284 mg/d) developed dyskinesia (P < 0.001). There were no significant differences in change in Unified Parkinson's Disease Rating Scale activities of daily living or motor scores, suggesting comparable efficacy between the two treatments. Adverse events were comparable in the two groups with nausea, dizziness, insomnia, back pain, arthralgia, somnolence, fatigue, and pain most commonly reported. Ropinirole prolonged‐release delayed the onset of dyskinesia with comparable efficacy to increased doses of levodopa in early PD patients not optimally controlled with levodopa. © 2010 Movement Disorder Society     

Amantadine extended release for levodopa‐induced dyskinesia in Parkinson's disease (EASED Study)

ADS‐5102 is a long‐acting, extended‐release capsule formulation of amantadine HCl administered once daily at bedtime. This study investigated the safety, efficacy, and tolerability of ADS‐5102 in Parkinson's disease (PD) patients with levodopa‐induced dyskinesia. This was a randomized, double‐blind, placebo‐controlled, parallel‐group study of 83 PD patients with troublesome dyskinesia assigned to placebo or one of three doses of ADS‐5102 (260 mg, 340 mg, 420 mg) administered daily at bedtime for 8 weeks. The primary efficacy analysis compared change from baseline to week 8 in Unified Dyskinesia Rating Scale (UDysRS) total score for 340 mg ADS‐5102 versus placebo. Secondary outcome measures included change in UDysRS for 260 mg, 420 mg, Fatigue Severity Scale (FSS), Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS‐UPDRS), patient diary, Clinician's Global Impression of Change, and Parkinson's Disease Questionnaire (PDQ‐39). ADS‐5102 340 mg significantly reduced dyskinesia versus placebo (27% reduction in UDysRS, P = 0.005). In addition, ADS‐5102 significantly increased ON time without troublesome dyskinesia, as assessed by PD patient diaries, at 260 mg (P = 0.004), 340 mg (P = 0.008) and 420 mg (P = 0.018). Adverse events (AEs) were reported for 82%, 80%, 95%, and 90% of patients in the placebo, 260‐mg, 340‐mg, and 420‐mg groups, respectively. Constipation, hallucinations, dizziness, and dry mouth were the most frequent AEs. Study withdrawal rates were 9%, 15%, 14%, and 40% for the placebo, 260‐mg, 340‐mg, and 420‐mg groups, respectively. All study withdrawals in the active treatment groups were attributable to AEs. ADS‐5102 was generally well tolerated and resulted in significant and dose‐dependent improvements in dyskinesia in PD patients. © 2015 Adamas Pharmaceuticals, Inc. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.     

Study of istradefylline in patients with Parkinson's disease on levodopa with motor fluctuations

The objective of this study was to evaluate the efficacy, safety, and tolerability of istradefylline 20 mg once daily versus placebo as an adjunct to levodopa in subjects with Parkinson's disease (PD) who have motor fluctuations. Istradefylline (KW‐6002) is an adenosine A_2A receptor antagonist that in primate models of PD improves motor function without causing or worsening dyskinesia. This 12‐week, multicenter, double‐blind, placebo‐controlled, randomized, Phase 3 study of istradefylline was conducted in subjects experiencing an average daily OFF time of at least 3 hours (116 randomized to istradefylline; 115 to placebo). All were on stable levodopa regimens; 90% were also on stable regimens of other anti‐Parkinson's medications. Istradefylline‐treated subjects had significant placebo‐corrected reductions in daily OFF time from baseline to endpoint: 4.6% (P = 0.03) and 0.7 hours (P = 0.03). For ON time with troublesome dyskinesia, the changes between istradefylline and placebo were not significant. Istradefylline was well tolerated, with 6 (5.2%) istradefylline‐treated and 7 (6.1%) placebo‐treated subjects withdrawing from the study because of adverse events. Dyskinesia, lightheadedness, tremor, constipation, and weight decrease were reported more often with istradefylline than placebo. We conclude that istradefylline is well tolerated and significantly reduces OFF time as an adjunct to levodopa in PD subjects with motor fluctuations. © 2008 Movement Disorder Society     

Levodopa normalizes exercise related cortico-motoneuron excitability abnormalities in Parkinson's disease.

OBJECTIVES: To measure exercise induced changes in cortico-motoneuron excitability in Parkinson's disease (PD) before and after levodopa. METHODS: Transcranial magnetic stimulation was delivered at 10% above resting motor threshold in 9 PD and 8 control subjects. Each subject performed repetitive isometric wrist extension at 50% of the baseline maximal voluntary contraction (MVC) for 30s with 3s rest between extensions until fatigued, defined as the inability to generate force at more than 25% of the baseline MVC. We recorded motor evoked potentials (MEPs) from the resting extensor carpi radialis muscle before (baseline), during, and after fatiguing exercise. Baseline electromyographic activity was closely monitored. We compared absolute MEP amplitudes between PD and controls, before and after levodopa, during baseline, exercise, and recovery periods. We correlated absolute MEP amplitudes with an objective measure of fatigability. RESULTS: PD subjects in the "off" state had increased absolute MEP amplitudes compared with controls. The effect was present in all 3 exercise periods. These differences disappeared after levodopa. Post-exercise facilitation was clear for PD subjects before and after levodopa, but post-exercise depression was not significant. Absolute MEP amplitude showed negative correlation with objective fatigability for PD subjects before levodopa. CONCLUSIONS: Levodopa normalized the increased cortico-motoneuron excitability in PD patients before, during, and after fatiguing exercise. SIGNIFICANCE: This study demonstrated the abnormal cortico-motoneuron excitability associated with motor fatigue in PD.     

Crossover comparison of IPX066 and a standard levodopa formulation in advanced Parkinson's disease

The objective of the study was to compare the pharmacokinetics, motor effects, and safety of IPX066, a novel extended‐release formulation of carbidopa‐levodopa, with an immediate‐release carbidopa‐levodopa formulation in advanced Parkinson's disease. We performed an open‐label crossover study in 27 subjects with advanced Parkinson's disease experiencing motor fluctuations on levodopa therapy. Subjects were randomized 1:1 to 8 days' treatment with either immediate‐release carbidopa‐levodopa followed by IPX066 or IPX066 followed by immediate‐release carbidopa‐levodopa. Pharmacokinetic and motor assessments were undertaken on day 1 for 8 hours (following a single dose) and on day 8 for 12 hours (during multiple‐dose administration). Following a single dose of IPX066 or immediate‐release carbidopa‐levodopa, plasma levodopa concentrations increased at a similarly rapid rate and were sustained above 50% of peak concentration for 4 hours with IPX066 versus 1.4 hours with immediate‐release carbidopa‐levodopa (P < .0001). Multiple‐dose data showed IPX066 substantially reduced variability in plasma levodopa concentrations despite a lower dosing frequency (mean, 3.5 vs 5.4 administrations per day). In addition, total levodopa exposure during IPX066 treatment was approximately 87% higher, whereas the increase in levodopa C_max was approximately 30% compared with immediate‐release carbidopa‐levodopa. Both products were well tolerated. IPX066 provided more sustained plasma levodopa concentrations than immediate‐release carbidopa‐levodopa. Larger, longer‐term, well‐controlled studies should be conducted to provide rigorous assessment of the clinical effects of IPX066. © 2011 Movement Disorder Society     

Fatigue in Parkinson's disease: The contribution of cerebral metabolic changes

Fatigue is a common and disabling non‐motor symptom in Parkinson's disease associated with a feeling of overwhelming lack of energy. The aim of this study was to identify the neural substrates that may contribute to the development of fatigue in Parkinson's disease. Twenty‐three Parkinson's disease patients meeting UK Brain Bank criteria for the diagnosis of idiopathic Parkinson's disease were recruited and completed the 2‐[¹⁸F]fluoro‐2‐deoxy‐D‐glucose (FDG)‐PET scan. The metabolic activities of Parkinson's disease patients with fatigue were compared to those without fatigue using statistical parametric mapping analysis. The Parkinson's disease group exhibiting higher level of fatigue showed anti‐correlated metabolic changes in cortical regions associated with the salience (i.e., right insular region) and default (i.e., bilateral posterior cingulate cortex) networks. The metabolic abnormalities detected in these brain regions displayed a significant correlation with level of fatigue and were associated with a disruption of the functional correlations with different cortical areas. These observations suggest that fatigue in Parkinson's disease may be the expression of metabolic abnormalities and impaired functional interactions between brain regions linked to the salience network and other neural networks. Hum Brain Mapp 38:283–292, 2017. © 2016 Wiley Periodicals, Inc.     

Characteristics of the sequence effect in Parkinson's disease

The sequence effect (SE) in Parkinson's disease (PD) is progressive slowing of sequential movements. It is a feature of bradykinesia, but is separate from a general slowness without deterioration over time. It is commonly seen in PD, but its physiology is unclear. We measured general slowness and the SE separately with a computer‐based, modified Purdue pegboard in 11 patients with advanced PD. We conducted a placebo‐controlled, four‐way crossover study to learn whether levodopa and repetitive transcranial magnetic stimulation (rTMS) could improve general slowness or the SE. We also examined the correlation between the SE and clinical fatigue. Levodopa alone and rTMS alone improved general slowness, but rTMS showed no additive effect on levodopa. Levodopa alone, rTMS alone, and their combination did not alleviate the SE. There was no correlation between the SE and fatigue. This study suggests that dopaminergic dysfunction and abnormal motor cortex excitability are not the relevant mechanisms for the SE. Additionally, the SE is not a component of clinical fatigue. Further work is needed to establish the physiology and clinical relevance of the SE. © 2010 Movement Disorder Society.     

Early treatment benefits of ropinirole prolonged release in Parkinson's disease patients with motor fluctuations

We performed a retrospective analysis of the Efficacy And Safety Evaluation in Parkinson's Disease (EASE‐PD) Adjunct Study, assessing the minimum time to symptom improvement after initiation of ropinirole prolonged release (2–24 mg/day) versus placebo in patients with moderate‐to‐advanced PD not optimally controlled with levodopa. Ropinirole prolonged release was superior to placebo at Week 2 for change from baseline in “off” time (adjusted mean treatment difference [AMTD] – 0.7 hours; 95% confidence interval [CI], –1.1, –0.2; P = 0.0029), and “on” time without troublesome dyskinesia (0.4 hours; 95%CI, 0.01, 0.88; P = 0.0444). At Week 4, improvements were seen in change from baseline in Unified Parkinson's Disease Rating Scale total motor score (AMTD, –3.1; 95%CI, –4.4, –1.8; P < 0.0001), activities of daily living score (AMTD, –1.1; 95%CI, –1.7, –0.5; P = 0.0004), and the cardinal symptoms of PD compared with placebo. These analyses indicate that once‐daily, adjunctive ropinirole prolonged release can offer PD symptom control 2 weeks after treatment initiation. © 2010 Movement Disorder Society     

Randomized,double‐blind,multicenter evaluation of pramipexole extended release once daily in early Parkinson's disease

The objective of this study was to evaluate the efficacy and safety of pramipexole extended release (ER) administered once daily in early Parkinson's disease (PD). Pramipexole immediate release (IR) administered three times daily (TID) is an efficacious and generally well‐tolerated treatment for PD. A pramipexole ER formulation is now available. We performed a randomized, double‐blind, placebo and active comparator–controlled trial in subjects with early PD. The primary efficacy and safety evaluation of pramipexole ER compared with placebo took place at week 18. Two hundred fifty‐nine subjects were randomized 2:2:1 to treatment with pramipexole ER once daily, pramipexole IR TID, or placebo. Levodopa rescue was required by 7 subjects in the placebo group (14%), 3 subjects in the pramipexole ER group (2.9%, P = 0.0160), and 1 subject in the pramipexole IR group (1.0%, P = 0.0017). Adjusted mean [standard error (SE)] change in Unified Parkinson Disease Rating Scale (UPDRS) II [activities of daily living (ADL)] + III (motor) scores from baseline to week 18, including post‐levodopa rescue evaluations, was ?5.1 (1.3) in the placebo group, ?8.1 (1.1) in the pramipexole ER group (P = 0.0282), and ?8.4 (1.1) in the pramipexole IR group (P = 0.0153). Adjusted mean (SE) change in UPDRS ADL + motor scores, censoring post‐levodopa rescue data, was ?2.7 (1.3) in the placebo group, ?7.4 (1.1) in the pramipexole ER group (P = 0.0010), and ?7.5 (1.1) in the pramipexole IR group (P = 0.0006). Adverse events more common with pramipexole ER than placebo included somnolence, nausea, constipation, and fatigue. Pramipexole ER administered once daily was demonstrated to be efficacious compared with placebo and provided similar efficacy and tolerability as pramipexole IR administered TID. © 2010 Movement Disorder Society     

Efficacy and safety of tolcapone in levodopa-treated Parkinson's disease patients with “wearing-off” phenomenon: a multicentre,double-blind,randomized, placebo-controlled trial

To assess the effect of tolcapone added to levodopa plus benserazide or carbidopa on the “wearing-off” phenomenon in patients with Parkinson's disease, we undertook a double-blind, randomized, placebo-controlled, parallel-group study of tolcapone 50, 200, or 400 mg three times daily (t.i.d.) for 6 weeks in addition to levodopa therapy. We studied 154 parkinsonian patients, aged 40 years or more, who presented with the “wearing-off” phenomenon despite “optimal” antiparkinsonian therapy. The main outcome measures were “on”- and “off”-time, Investigator's Global Assessments, Subscales of the Unified Parkinson's Disease Rating Scale, changes in levodopa dosage, and safety and tolerability. Tolcapone was more effective than placebo in reducing the “wearing-off” phenomenon between baseline and week 6 at all three dosages. Tolcapone 200 mg t.i.d. increased “on”-time from 37.9% of the waking day to 50.8% (p < 0.01) and reduced “off”-time from 26.7% of the waking day to 16.4% (p < 0.05). Tolcapone treatment was generally well tolerated at all dosages. Initial exacerbation of adverse dopaminergic effects was controlled by levodopa dosage adjustment; at week 6, the mean total daily levodopa dosage had decreased by 80 mg, from 694 mg at baseline, in the tolcapone 200 mg t.i.d. group (p < 0.01). We conclude that the addition of tolcapone to levodopa plus a decarboxylase inhibitor effectively and safely reduces the “wearing-off” phenomenon in parkinsonian patients.     

Reduced plasma taurine level in Parkinson's disease: association with motor severity and levodopa treatment

Purpose: This study aimed to evaluate the level of taurine in plasma, and its association with the severity of motor and non-motor symptoms (NMS) and chronic levodopa treatment in Parkinson's disease (PD). Patients and methods: Plasma taurine level was measured in treated PD (tPD), untreated PD (ntPD) and control groups. Motor symptoms and NMS were assessed using the Unified Parkinson's Disease Rating Scale, the short form of the McGill Pain Questionnaire, the Hamilton Depression Scale, the Scale for Outcomes in Parkinson's disease for Autonomic Symptoms and the Pittsburgh Sleep Quality Index. Longtime exposure to levodopa was indicated by its approximate cumulative dosage. Results: The plasma taurine levels of PD patients were decreased when compared with controls and negatively associated with motor severity but not NMS. Moreover, tPD patients exhibited lower levels of plasma taurine than ntPD patients. Interestingly, plasma taurine levels negatively correlated with cumulative levodopa dosage in tPD. After controlling for potential confounders, the association between taurine and levodopa remained significant. Conclusion: Our study supports that taurine may play important roles in the pathophysiology of PD and the disturbances caused by chronic levodopa administration.     

Long‐term follow‐up of impulse control disorders in Parkinson's disease

Recent studies have linked dopamine agonist (DA) usage with the development of impulse control disorders (ICDs) in Parkinson's disease (PD). Little is known about optimal management strategies or the long‐term outcomes of affected patients. To report on the clinical interventions and long‐term outcomes of PD patients who developed an ICD after DA initiation. Subjects contacted by telephone for a follow‐up interview after a mean time period of 29.2 months. They were administered a modified Minnesota Impulse Disorder Interview for compulsive buying, gambling, and sexuality, and also self‐rated changes in their ICD symptomatology. Baseline and follow‐up dopamine replacement therapy use was recorded and verified by chart review. Of 18 subjects, 15 (83.3%) participated in the follow‐up interview. At follow‐up, patients were receiving a significantly lower DA levodopa equivalent daily dosage (LEDD) (Z = ?3.1, P = 0.002) and a higher daily levodopa dosage (Z = ?1.9, P = 0.05), but a similar total LEDD dosage (Z = ?0.47, P = 0.64) with no changes in Unified Parkinson's Disease Rating Scale motor score (Z = ?1.3, P = 0.19). As part of ICD management, 12 (80.0%) patients discontinued or significantly decreased DA treatment, all of whom experienced full or partial remission of ICD symptoms by self‐report, and 10 (83.3%) of whom no longer met diagnostic criteria for an ICD. For PD patients who develop an ICD in the context of DA treatment, discontinuing or significantly decreasing DA exposure, even when offset by an increase in levodopa treatment, is associated with remission of or significant reduction in ICD behaviors without worsening in motor symptoms. © 2007 Movement Disorder Society     

Fatigue in Japanese patients with Parkinson's disease: A study using Parkinson fatigue scale

The objective of this multicenter cross‐sectional study was to determine the prevalence of fatigue and factors contributing to it in a large sample of Japanese patients with Parkinson's disease (PD). We used the 16‐item Parkinson Fatigue Scale (PFS‐16), which was designed to assess fatigue exclusively associated with PD. We carried out this study using PFS‐16, the Unified Parkinson's Disease Rating Scale, Zung's Self‐Rating Depression Scale, Parkinson's Disease Sleep Scale (PDSS), and the PD quality of life (QOL) scale (PDQ‐39) by interview using questionnaires and physical examination by neurologists in 361 nondemented PD patients. Fatigue (an average PFS score of 3.3 or greater) was revealed in 151 patients (41.8%). Multiple logistic regression analysis indicated that the significant independent variables related to the presence of fatigue were the scores of PDSS and PDQ‐39. Depression score was not a significant contributing factor. Our study revealed that the prevalence of fatigue in Japanese PD patients is as high as that in Western countries, and that fatigue is a relatively independent symptom, although sleep disturbance may be associated with fatigue. Since fatigue is significantly related to QOL reduction, therapeutic interventions including treatment of sleep disturbance are important. © 2009 Movement Disorder Society     

Post-exercise facilitation and depression of motor evoked potentials to transcranial magnetic stimulation: a study in multiple sclerosis.

OBJECTIVE: To evaluate motor cortex excitability changes by transcranial magnetic stimulation (TMS) following repetitive muscle contractions in patients with multiple sclerosis (MS); to state whether a typical pattern of post-exercise motor evoked potentials (MEPs) is related to clinical fatigue in MS. METHODS: In 41 patients with definite MS (32 with fatigue and 9 without fatigue according to Fatigue Severity Scale) and 13 controls, MEPs were recorded at rest: at baseline condition, following repetitive contractions until fatigue, and after fatigue, to evaluate post-exercise MEP facilitation (PEF) and depression (PED). RESULTS: After exercise, MEP amplitude significantly increased both in patients and controls (PEF). When fatigue set in, MEP amplitude was significantly reduced in normal subjects (PED), but not in patients. Post-exercise MEP findings were similar both in patients with and without fatigue. CONCLUSIONS: Our findings suggest an intracortical motor dysfunction following a voluntary contraction in MS patients, possibly due to failure of depression of facilitatory cortical circuits, or alternatively of inhibitory mechanisms.     

Mavoglurant (AFQ056) in combination with increased levodopa dosages in Parkinson's disease patients

Long-term use of levodopa (L-dopa) in patients with Parkinson's disease is associated with development of dyskinesia. This study explored whether Parkinson's disease patients with L-dopa-induced dyskinesia experience improved OFF-time from higher L-dopa doses without worsening of dyskinesias when receiving adjunctive mavoglurant. Patients with moderate-to-severe L-dopa-induced dyskinesia were randomized to receive mavoglurant or placebo. Mavoglurant (AFQ056) was up-titrated over two weeks from 25 mg twice daily (bid) to 100 mg bid (L-dopa kept stable), followed by three weeks during which the daily L-dopa dosage was increased by up to 300 mg/day. A sample size of 30 was initially planned; however, the study was terminated prematurely due to enrollment challenges. OFF-time showed greater improvements in the mavoglurant group (n = 7) compared with the placebo group (n = 7); difference at week 5 was –2.77 h (90% confidence interval –5.44, –0.09 h; p = 0.09). ON-time without troublesome dyskinesia increased more from baseline to week 5 in the mavoglurant group (4.38 h) versus the placebo group (0.63 h). Clinician-rated measures were conflicting. The Modified Abnormal Involuntary Movement Scale scores showed a slight improvement with mavoglurant compared with placebo, while the Unified Dyskinesia Rating Scale parts III and IV worsened slightly with mavoglurant compared with placebo. Due to the low patient numbers and conflicting clinician-rated outcomes data, our findings are not conclusive. However, our results suggest that mavoglurant combined with higher doses of L-dopa may be effective in treating patients with Parkinson's disease experiencing L-dopa-related motor fluctuations and dyskinesias.     

Nonmotor symptoms evolution during 24 months of bilateral subthalamic stimulation in Parkinson's disease

Background: The objective of this study was to investigate 24‐month of effects of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) on nonmotor symptoms in Parkinson's disease (PD). Methods: In this prospective, observational, multicenter, international study including 67 PD patients undergoing bilateral STN‐DBS, we examined the Non‐motor Symptom Scale, Non‐Motor Symptoms Questionnaire, Parkinson's Disease Questionnaire‐8, Scales for Outcomes in Parkinson's Disease‐motor examination, ‐activities of daily living, and ‐complications, and levodopa‐equivalent daily dose preoperatively and at 5 and 24‐month of follow‐up. After checking distribution normality, longitudinal outcome changes were investigated with Friedman tests or repeated‐measures analysis of variance and Bonferroni correction for multiple comparisons using multiple tests. Post hoc, Wilcoxon signed rank t tests were computed to compare visits. The strength of clinical responses was analyzed using effect size. Explorative Spearman correlations of change scores from baseline to 24‐month follow‐up were calculated for all outcomes. Results: The Non‐motor Symptom Scale and all other outcome parameters significantly improved from baseline to the 5‐month follow‐up. From 5 to 24‐month, partial decrements in these gains were found. Nonetheless, comparing baseline with 24‐month follow‐up, significant improvements were observed for the Non‐motor Symptom Scale (small effect), Scales for Outcomes in PD‐motor examination showed a moderate effect, and Scales for Outcomes in Parkinson's Disease‐complications and levodopa‐equivalent daily dose showed large effects. Non‐motor Symptom Scale change scores from baseline to 24‐month follow‐up correlated significantly with Parkinson's Disease Questionnaire‐8, Scales for Outcomes in Parkinson's Disease‐activities of daily living, and ‐motor complications change scores. Conclusions: This study provides evidence of beneficial effects of bilateral STN‐DBS on nonmotor symptoms at 24‐month follow‐up. The extent of nonmotor symptom improvement was directly proportionate to improvements in quality of life, activities of daily living, and motor complications. This study underlines the importance of nonmotor symptoms for holistic assessments of DBS outcomes. © 2018 International Parkinson and Movement Disorder Society