Safety and efficacy of continuous subcutaneous levodopa-carbidopa infusion (ND0612) for Parkinson's disease with motor fluctuations (BouNDless): a phase 3, randomised, double-blind, double-dummy, multicentre trial.

BACKGROUND: Conventional oral levodopa therapy for the treatment of Parkinson's disease can be associated with variations in plasma concentrations. Levodopa infusion strategies might provide more consistent drug delivery and fewer motor fluctuations. We aimed to assess the safety and efficacy of a continuous 24 h/day subcutaneous infusion of ND0612 (a levodopa-carbidopa solution) compared with oral immediate-release levodopa-carbidopa for the treatment of motor fluctuations in people with Parkinson's disease. METHODS: We conducted a phase 3, randomised, double-blind, double-dummy, active-controlled, multicentre trial at 117 academic and community neurology sites in 16 countries, including in Europe, Israel, and the USA. Eligible participants were men and women aged 30 years or older with a diagnosis of Parkinson's disease (Hoehn and Yahr stage ≤3 in the on state) who experienced at least 2·5 h/day of off time. Participants underwent an open-label run-in phase (<12 weeks), during which time optimal regimens were established for both oral immediate-release levodopa-carbidopa and for 24 h/day subcutaneous ND0612 infusion (levodopa-carbidopa 60·0/7·5 mg/mL), with supplemental oral levodopa-carbidopa if needed. Participants were then randomly assigned (1:1) to 12 weeks of double-blind treatment with their optimised regimen of either subcutaneous ND0612 or oral levodopa-carbidopa, with matching oral or subcutaneous placebo given as required to maintain blinding. Randomisation was done via an interactive web response system, stratified by region, using a permuted block schedule. Participants, study partners, treating investigators, study site personnel, and the sponsor were masked to treatment group allocation. The primary efficacy endpoint was the change from baseline (ie, time of randomisation, when all patients were receiving an optimised open-label ND0612 regimen) to end of the double-blind phase in total daily on time without troublesome dyskinesia, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, NCT04006210, and is complete. FINDINGS: Between Sept 30, 2019, and April 8, 2022, 381 participants were enrolled, of whom 259 (68%) were randomly assigned, 128 (49%) to subcutaneous ND0612 and 131 (51%) to oral levodopa-carbidopa. 243 (94%) participants completed the study. Treatment with subcutaneous ND0612 provided an additional 1·72 h (95% CI 1·08 to 2·36) of on time without troublesome dyskinesia compared with oral levodopa-carbidopa (change from baseline of -0·48 h [-0·94 to -0·02] with subcutaneous ND0612 vs -2·20 h [-2·65 to -1·74] with oral levodopa-carbidopa; p<0·0001). Significant treatment differences favouring subcutaneous ND0612 were also found in the first four of nine prespecified hierarchical outcomes of daily off time (-1·40 h [95% CI -1·99 to -0·80]), Movement Disorders Society-Unified Parkinson's Disease Rating Scale part II scores (-3·05 [-4·28 to -1·81]), Patients Global Impression of Change (odds ratio [OR] 5·31 [2·67 to 10·58]), and Clinical Global Impression of Improvement (OR 7·23 [3·57 to 14·64]). Hierarchical testing ended after the fourth secondary endpoint. Adverse events were reported by 287 (89%) of 322 participants during open-label ND0612 optimisation, and by 103 (80%) of 128 in the ND0612 group and 97 (74%) of 131 in the oral levodopa-carbidopa group during the double-blind phase. The most common adverse events were infusion-site reactions (266 [83%] participants during open-label ND0612, and 73 [57%] in the ND0612 group vs 56 [43%] in the oral levodopa-carbidopa group during the double-blind phase), most of which were mild. Serious adverse events in four participants in the ND0612 group were related to study treatment (infusion-site cellulitis [n=2], infusion-site abscess and infusion-site ulcer [n=1]; and paraesthesia and peripheral sensorimotor neuropathy [n=1]). One participant in the ND0612 group died during the double-blind phase, but the death was not related to study treatment (fall leading to traumatic brain injury). INTERPRETATION: Results of this phase 3 study showed that subcutaneous ND0612 used in combination with oral immediate-release levodopa-carbidopa increased on time without troublesome dyskinesia and reduced off time, with a favourable benefit-risk profile. ND0612 might offer a safe and efficacious subcutaneous levodopa infusion approach to managing motor fluctuations in people with Parkinson's disease. The ongoing open-label extension phase will provide further information on the long-term efficacy and safety of treatment. FUNDING: NeuroDerm.

Second-generation antipsychotics for Parkinson's disease psychosis: A systematic review and network meta-analysis.

OBJECTIVE: This network meta-analysis assessed the efficacy, tolerability, and acceptability of second-generation antipsychotics (SGAs) for Parkinson's disease psychosis (PDP). METHODS: We searched PubMed, Embase, Cochrane Library, and ClinicalTrials.gov for randomized controlled trials investigating SGAs for PDP up to October 26, 2023. RESULTS: We included 16 trials (N = 1252) investigating clozapine, melperone, olanzapine, pimavanserin, quetiapine, ulotaront, and placebo. In comparisons between SGAs and placebo, the findings were: i) Standardized mean differences, 95% confidence intervals (SMDs, 95%CIs), for psychotic-symptom reduction revealed the first rank of clozapine (-1.31, -1.73 to -0.89), the second rank of pimavanserin, with significant inferiority of quetiapine (SMD = 0.47, 0.02 to 0.92); ii) Mean differences (MDs, 95%CIs) for abnormal movement, as assessed by the Unified Parkinson's Disease Rating Scale - Part III, indicated that clozapine had the least motor side effects (-0.92, -2.75 to 0.91); iii) Risk ratios (RRs, 95% CIs) for adverse-effect dropout rates were lowest for melperone (1.02, 0.20 to 5.24); and iv) RRs (95% CIs) for all-cause dropout rates were lowest for clozapine (0.73, 0.42 to 1.25). CONCLUSIONS: For patients with PDP, clozapine may substantially reduce psychotic symptoms with minimal abnormal movement, high acceptability, and moderate overall tolerability. Pimavanserin, not quetiapine, could be an alternative.

Cath-KP, a novel peptide derived from frog skin, prevents oxidative stress damage in a Parkinson's disease model.

Parkinson's disease (PD) is a neurodegenerative condition that results in dyskinesia, with oxidative stress playing a pivotal role in its progression. Antioxidant peptides may thus present therapeutic potential for PD. In this study, a novel cathelicidin peptide (Cath-KP; GCSGRFCNLFNNRRPGRLTLIHRPGGDKRTSTGLIYV) was identified from the skin of the Asiatic painted frog ( Kaloula pulchra). Structural analysis using circular dichroism and homology modeling revealed a unique αßß conformation for Cath-KP. In vitro experiments, including free radical scavenging and ferric-reducing antioxidant analyses, confirmed its antioxidant properties. Using the 1-methyl-4-phenylpyridinium ion (MPP +)-induced dopamine cell line and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice, Cath-KP was found to penetrate cells and reach deep brain tissues, resulting in improved MPP +-induced cell viability and reduced oxidative stress-induced damage by promoting antioxidant enzyme expression and alleviating mitochondrial and intracellular reactive oxygen species accumulation through Sirtuin-1 (Sirt1)/Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway activation. Both focal adhesion kinase (FAK) and p38 were also identified as regulatory elements. In the MPTP-induced PD mice, Cath-KP administration increased the number of tyrosine hydroxylase (TH)-positive neurons, restored TH content, and ameliorated dyskinesia. To the best of our knowledge, this study is the first to report on a cathelicidin peptide demonstrating potent antioxidant and neuroprotective properties in a PD model by targeting oxidative stress. These findings expand the known functions of cathelicidins, and hold promise for the development of therapeutic agents for PD.

Metoclopramide-induced acute dystonic reaction: A pediatric case report.

INTRODUCTION: This case report presents a unique acute dystonic reaction (ADR) induced by metoclopramide in a 6-year-old male patient with pertussis-associated vomiting. The rarity of such a reaction in pediatric patients underscores the significance of this case in contributing to the scientific literature. This report highlights the need for heightened awareness of the potential adverse effects of medications commonly used in pediatrics and emphasizes the importance of tailored interventions for this population. MAIN SYMPTOMS AND IMPORTANT CLINICAL FINDINGS: Following the administration of metoclopramide for vomiting associated with pertussis cough, the patient exhibited distressing symptoms, including torticollis, facial grimacing, and tongue protrusion. These involuntary movements were promptly recognized, leading to the suspicion of an ADR. The clinical findings underscore the importance of vigilant monitoring for extrapyramidal symptoms following medication administration, especially in children. THE MAIN DIAGNOSES, THERAPEUTIC INTERVENTIONS, AND OUTCOMES: The primary diagnosis of ADR induced by metoclopramide was confirmed, prompting the cessation of the medication and the initiation of anticholinergic therapy with benztropine. This intervention rapidly resolved the patient's symptoms, highlighting the importance of tailored and swift therapeutic strategies. The outcome demonstrated the efficacy of timely intervention in managing ADR in pediatric patients. CONCLUSION: The main takeaway lesson from this case lies in the critical need for healthcare practitioners to remain vigilant for potential adverse reactions in pediatric patients, even when prescribing commonly used medications. The successful management of this case underscores the importance of prompt recognition, appropriate interventions, and continuous monitoring. Ultimately, this case contributes to the scientific literature by highlighting the unique manifestation of ADR in a pediatric patient, reinforcing the significance of individualized patient care and medication safety.

Safety and tolerability of long-term apomorphine infusion in advanced Parkinson's disease: an Indian multi-center (APO-IND) experience.

Advanced Parkinson's Disease (APD) is complicated by the emergence of motor and non-motor fluctuations, which are initially predictable and eventually become unpredictable, in part due to erratic gastric absorption and short half of oral levodopa. Attempts to manage such fluctuations with oral dopaminergic drugs often lead to disabling dyskinesias. Continuous Subcutaneous Apomorphine Infusion (CSAI), despite being approved for the treatment of APD since 1993, was approved in India only in 2019. We studied the safety, tolerability and efficacy of CSAI in Indian patients with APD in a registry design to raise local awareness of this important treatment. We conducted a prospective registry-based observational audit at 10 centers across different states of India. Patients with APD, not responding to or with significant side effects from oral dopaminergic therapy, were assessed at baseline and at month 6 and 12 following CSAI infusion. Fifty-one patients completed the study, CSAI significantly reduced the functional impact of dyskinesia (p < 0.01 at 6 months and p < 0.001 at 12 months). There was a significant improvement in the OFF-state from baseline (p < 0.01 at 6 months and p < 0.001 at 12 months) No discernible side effects were observed apart from mild site reaction (n = 7), nausea (n = 7) skin nodules (n = 2). CSAI demonstrated safety, efficacy, tolerability and improved quality of life in patients with APD, as shown in previous studies. Our study highlighted current existing inequalities in treatment availability, lack of awareness, knowledge gap, affordability and cost remains a concern regarding apomorphine use in Indian PD population.

Levodopa-Carbidopa Intestinal Gel Injection for Patient with Severe Parkinson's Disease Followed by Total Hip Arthroplasty: A Case Report and Literature Review.

BACKGROUND: Patients with Parkinson's disease have a high dislocation rate after total hip arthroplasty (THA). This study describes a case with severe Parkinson's disease who developed rapidly destructive coxarthrosis (RDC) and underwent THA using a dual mobility cup after a levodopa-carbidopa intestinal gel (LCIG) infusion. CASE PRESENTATION: The patient is a 59-year-old female with a ten-year history of Parkinson's disease, which was first treated with oral levodopa. The patient developed RDC of the right hip joint. However, THA was difficult owing to Parkinson's disease and its treatment side effects, such as wearing-off, dyskinesia, and freezing of the gait, Thus, LCIG was initiated, and improvement in wearing-off and dyskinesia was observed. Two months after the LCIG therapy, the disease was controlled well. THA was subsequently performed using a dual mobility cup to prevent postoperative dislocation. Postoperatively, LCIG therapy was continuously administered to carefully manage the disease, which was controlled well with no increase in wearing-off and dyskinesia after surgery. At 1 year after surgery, the walking speed, stride length, and the Harris hip score improved compared to preoperatively. The UPDRS III motor score improved to eight without signs of wearing-off or dyskinesia. The Hoehn-Yahr scale was II in the "on" period and remained unchanged 1 year after surgery. The patient could walk without a cane and had satisfactory functional outcomes. CONCLUSION: This case proved that LCIG treatment performed preoperatively, followed by THA using a dual mobility cup, and strict management of Parkinson's disease could result in a satisfactory clinical course without recurrence of wearing-off and dyskinesia. Similar procedures may benefit other patients with Parkinson's disease who have previously been deemed unsuitable for THA.

Amantadine for Refractory Tremor in Parkinson Disease and Other Indications: A Chart Review With Long-Term Follow-up.

OBJECTIVES: The aim of this study was to determine how amantadine was used in a movement disorders clinic and how effective it was. METHODS: A chart review over a 2-month period in 2022 of all patients in a movement disorders clinic who had ever taken amantadine was undertaken. RESULTS: One hundred six charts were included. Amantadine was initiated primarily for tremor and secondly for l -dopa-induced dyskinesias (LIDs). Sixty-two percent of tremor patients improved and tolerated amantadine; 74% of those with LID improved and tolerated the drug. Hallucinations occurred in 23%. Initiating amantadine as a syrup allowed a more conservative titration than other formulations, which is attractive given the high percentage of hallucinations that may occur. Patients who tolerated drug initiation were generally kept on the drug for many years. CONCLUSIONS: Amantadine should be considered as adjunctive therapy in Parkinson disease patients with refractory tremor as well as for LIDs.

Continuous subcutaneous levodopa-carbidopa for the treatment of advanced Parkinson's disease: is it an improvement on other delivery?

INTRODUCTION: Parkinson's disease (PD) is the second most common neurodegenerative disease and is growing in prevalence and disability. The standard treatment for PD is oral levo-dopa (LD) with carbidopa (CD). As PD progresses, despite higher doses of LD/CD, plasma levels of LD fluctuate, and may be associated with motor fluctuations and dyskinesia. AREAS COVERED: The development of two new subcutaneous preparations of LD/CD (ND0612 and ABBV-951) for the treatment of motor fluctuations in PD is described in detail. Both reduce motor fluctuations and dyskinesia with minor infusion site adverse events. A third subcutaneous preparation, DIZ102, is in early-stage development. EXPERT OPINION: The premise for using continuous release LD in advanced PD is that steady state levels of LD will prevent motor fluctuations/dyskinesia, but this is not the whole story, and will limit the benefits of subcutaneous continuous release LD. With its present pump system ND0612 cannot be used as monotherapy, whereas ABBV-951 can be. Having to combine with oral LD/CD will complicate the use of ND0612. Both ND0612 and ABBV-951 only cause modest reductions in OFF time. It is not clear whether these subcutaneous preparations will have more benefits than the intestinal gel, which also reduces OFF time and dyskinesia.

Safety review of current pharmacotherapies for levodopa-treated patients with Parkinson's disease.

INTRODUCTION: Levodopa remains the gold standard for treatment of Parkinson's disease (PD). Patients develop complications with disease progression, necessitating adjunctive therapy to control fluctuations in motor and non-motor symptoms and dyskinesia. Knowledge of medication safety and tolerability is critical to ascertain the benefit-risk ratio and select an adjunctive therapy that provides the highest chance for medication adherence. Posing a challenge are the sheer abundance of options, stemming from the development of several new drugs in recent years, as well as differences in commercial drug availability worldwide. AREAS COVERED: This review evaluates the efficacy, safety, and tolerability of current US FDA-approved pharmacotherapies for levodopa-treated PD patients, including dopamine agonists, monoamine oxidase type-B inhibitors, catechol-O-methyltransferase inhibitors, the N-methyl-D-aspartate receptor antagonist amantadine, and the adenosine receptor antagonist istradefylline. Data were taken from pivotal phase III randomized controlled and post-surveillance studies, when available, that directly led to FDA-approval. EXPERT OPINION: No strong evidence exists to support use of a specific adjunctive treatment for improving Off time. Only one medication has demonstrated improvement in dyskinesia in levodopa-treated PD patients; however, every patient cannot tolerate it and therefore adjunctive therapy should be tailored to an individual's symptoms and risk for specific adverse effects.

Parkinson's disease - current treatment.

PURPOSE OF REVIEW: The purpose is to review the results and impact of recent studies for current and future treatment of both motor and non-motor symptoms in Parkinson's disease (PD). RECENT FINDINGS: New formulations of levodopa further optimize motor fluctuations, allowing for more on-time and less dyskinesia. On demand apomorphine continues to showcase itself as an effective and tolerable tool for treating motor off-periods. Though there are no clear treatment guidelines for PD-related constipation and sleep related disorders, several new agents for these non-motor symptoms show promising preliminary data. Expiratory muscle strength training may represent a useful and cost-effective strategy to alleviate oropharyngeal dysphagia associated with PD. There is evidence to suggest that the use of shorter pulse width and directional deep brain stimulation leads can results in a greater therapeutic window. SUMMARY: Though no interventions currently exist to significantly modify the disease progression of PD, new studies continue to give insight into optimal symptomatic management. Clinicians should be familiar with expanding the repertoire of tools available to treat the diverse range of symptoms and challenges associated with PD.

Doxycycline to treat levodopa-induced dyskinesias in Parkinson's disease: a preliminary study.

BACKGROUND: Levodopa-induced dyskinesia (LID) is a common motor complication of levodopa therapy in patients with Parkinson's disease (PD). Doxycycline is a widely used and inexpensive tetracycline with anti-inflammatory properties. OBJECTIVE: To evaluate the efficacy and safety of doxycycline in patients with PD and LID. METHODS: This was an open-label, uncontrolled, single-arm, single-center, phase 2 proof-of-concept study in patients with PD with functional impact of dyskinesia, which used levodopa three times daily, in a movement disorders clinic in Brazil. Participants were treated with doxycycline 200 mg/day for 12 weeks, with evaluations at baseline, week 4, and week 12 of treatment. The primary outcome measure was the change from baseline in the Unified Dyskinesia Rating Scale (UDysRS) total score at week 12, evaluated by two blinded raters. Key secondary outcomes measures were OFF time and ON time with troublesome dyskinesia in the PD home diary. RESULTS: Eight patients with PD were treated and evaluated. Doxycycline 200 mg/day reduced the UDysRS total score at week 12, compared with baseline (Friedman χ2 = 9.6; p = 0.008). Further, doxycycline reduced the ON time with troublesome dyskinesia (Friedman χ2 = 10.8; p = 0.004) without worsening parkinsonism. There were no severe adverse events, and dyspepsia was the commonest event. CONCLUSION: In this preliminary, open-label and uncontrolled trial, doxycycline was effective in reducing LID and safe after a 12-week treatment. Further well-designed placebo-controlled clinical trials with a longer duration and a larger number of participants are needed. CLINICAL TRIAL REGISTRATION: https://ensaiosclinicos.gov.br, identifier: RBR-1047fwbf.

ANTECEDENTES: A discinesia induzida por levodopa (DIL) é uma complicação motora comum da terapia com levodopa em pacientes com doença de Parkinson (DP). A doxiciclina é uma tetraciclina amplamente usada e barata, com propriedade anti-inflamatória. OBJETIVO: Avaliar a eficácia e segurança da doxiciclina em pacientes com DP e DIL. MéTODOS: Este foi um estudo aberto, não-controlado, de braço único, monocêntrico, fase 2 e de prova de conceito, em pacientes com DP e impacto funcional das discinesias, que usavam levodopa três vezes ao dia, em um ambulatório de distúrbios de movimento no Brasil. Os participantes foram tratados com doxiciclina 200 mg/dia por 12 semanas, com avaliações na base, na semana 4 e na semana 12 do tratamento. A medida de desfecho primário foi a mudança no escore total da Unified Dyskinesia Rating Scale (UDysRS) da base à semana 12, avaliada por dois avaliadores cegos. As medidas-chave de desfecho secundário fora o tempo em OFF e tempo em ON com discinesia problemática. RESULTADOS: Oito pacientes com DP foram tratados e avaliados. A doxiciclina 200 mg/dia reduziu o escore total da UDysRS na semana 12, comparado com a avaliação inicial (χ2 de Friedman = 9.6; p = 0.008). Além disso, a doxiciclina reduziu o tempo em ON com discinesia problemática (χ2 de Friedman = 10.8; p = 0.004) sem piorar o parkinsonismo. Não houve eventos adversos graves, e dispepsia foi o evento mais comum. CONCLUSãO: No presente estudo preliminar, aberto e não-controlado, a doxiciclina foi eficaz em reduzir as DIL e segura após tratamento por 12 semanas. Estudos clínicos bem-desenhados e placebo-controlados adicionais, com duração mais longa e maior número de participantes, são necessários.

The effects of sigma-1 agonist fluvoxamine on experimental induced tardive dyskinesia model in rats.

Tardive dyskinesia (TD) is a persistent involuntary complex movement disorder that is known to occur with long-term antipsychotic treatment. Despite being a well-recognized complication of this treatment, its symptoms are often masked by the antipsychotic agents, only to become apparent upon reducing or terminating the treatment. In an effort to advance our understanding of TD pathophysiology and to identify potential therapies, the current study aimed to establish an animal model of TD by administering haloperidol to rats and to evaluate the efficacy of fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), in ameliorating TD symptoms. The study compared the behavioral and biochemical parameters of rats that were treated with either fluvoxamine, tetrabenazine, haloperidol, or saline (control group). The biochemical parameters of interest included the brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), superoxide dismutase (SOD), and malondialdehyde (MDA). To achieve the study objectives, 32 male Wistar Albino rats were assigned to four different groups. The control group received physiological saline for six weeks. The haloperidol group received 1 mg/kg/ip haloperidol for the first three weeks, followed by two weeks of saline. The haloperidol+fluvoxamine group received 1 mg/kg/ip haloperidol for the first three weeks, followed by 30 mg/kg/ip fluvoxamine. The haloperidol+tetrabenazine group was administered 1 mg/kg/ip haloperidol for the first three weeks, followed by 5 mg/kg/ip tetrabenazine. Behavioral assessments of the rats were performed by measuring vacuous chewing movements. Subsequently, samples were collected from the hippocampus, striatum, and frontal lobe tissues of the rats, and BDNF, NGF, SOD, and MDA levels were measured. The results of the study demonstrated significant differences between the groups with respect to behavioral observations. Furthermore, SOD levels in the hippocampus, as well as BDNF, NGF, and SOD levels in the striatum of the haloperidol+fluvoxamine group were significantly higher than those observed in the haloperidol group. Conversely, MDA levels in the hippocampus were significantly lower in the haloperidol+fluvoxamine group than in the haloperidol group. These findings provide evidence of the beneficial effects of fluvoxamine, acting as a sigma-1 agonist, in treating TD symptoms induced experimentally. The observed benefits were supported by the biochemical investigations performed on brain tissue samples. Therefore, fluvoxamine may be considered as a potential alternative treatment for TD in clinical practice, although further research is needed to corroborate these findings.

Timely referral for device-aided therapy in Parkinson's disease. Development of a screening tool.

BACKGROUND: Timely referral of Parkinson's disease (PD) patients to specialized centers for treatment with device-aided therapies (DAT) is suboptimal. OBJECTIVE: To develop a screening tool for timely referral for DAT in PD and to compare the tool with the published 5-2-1 criteria. METHODS: A cross-sectional, observational study was performed in 8 hospitals in the catchment area of a specialized movement disorder center in the Northern part of the Netherlands. The target population comprised PD patients not yet on DAT visiting the outpatient clinic of participating hospitals. The primary outcome was apparent eligibility for referral for DAT based on consensus by a panel of 5 experts in the field of DAT. Multivariable logistic regression modelling was used to develop a screening tool for eligibility for referral for DAT. Potential predictors were patient and disease characteristics as observed by attending neurologists. RESULTS: In total, 259 consecutive PD patients were included, of whom 17 were deemed eligible for referral for DAT (point prevalence: 6.6%). Presence of response fluctuations and troublesome dyskinesias were the strongest independent predictors of being considered eligible. Both variables were included in the final model, as well as levodopa equivalent daily dose. Decision curve analysis revealed the new model outperforms the 5-2-1 criteria. A simple chart was constructed to provide guidance for referral. Discrimination of this simplified scoring system proved excellent (AUC after bootstrapping: 0.97). CONCLUSIONS: Awaiting external validation, the developed screening tool already appears promising for timely referral and subsequent treatment with DAT in patients with PD.

Low serum uric acid levels and levodopa-induced dyskinesia in Parkinson's disease.

BACKGROUND: Levodopa is the most used and effective medication for motor symptoms of Parkinson disease (PD), its long-term use is associated with the appearance of levodopa-induced dyskinesia (LID). Uric acid (UA) is believed to play an important neuroprotective role in PD. OBJECTIVE: To investigate if serum UA levels are related with the presence of LIDs in PD patients. Also, we investigated the associations among UA levels and clinical features of PD. METHODS: We enrolled 81 PD patients (dyskinesia = 48; no dyskinesia = 33) in the present study. A blood sample was collected to evaluate serum UA levels, clinical evaluation included the following instruments: Montreal Cognitive Assessment (MoCA), Beck Depression Inventory II (BDI-II), MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Hoehn and Yahr (HY), and the sub-item 4.1 of MDS-UPDRS IV (score ≥ 1). Additional relevant clinical information was obtained by a clinical questionnaire. RESULTS: Serum UA levels were lower in the dyskinesia group when compared with the no dyskinesia group. The same result was found in the UA levels of both men and women. The multivariate analysis showed lower uric acid levels were significantly associated with having dyskinesia (odds ratio [OR] = 0.424; 95% confidence interval [CI]: 0.221-0.746; p = 0.005). Additional analysis verified that serum UA levels are inversely correlated with depressive symptoms, disease duration, MDS-UPDRS IV and time spent with dyskinesia. A positive correlation was found with age at onset of PD symptoms. CONCLUSIONS: The present study provides a possible role of serum UA levels in LID present in PD patients.

ANTECEDENTES: A levodopa é a medicação mais utilizada e eficaz para os sintomas motores da doença de Parkinson (DP); seu uso a longo prazo está associado ao aparecimento de discinesia induzida por levodopa (LID). Acredita-se que o ácido úrico desempenhe um importante papel neuroprotetor na DP. OBJETIVO: Investigar se os níveis séricos de AU estão relacionados com a presença de LID em pacientes com DP. Além disso, investigamos as associações entre os níveis de AU e as características clínicas da DP. MéTODOS: Foram incluídos 81 pacientes com DP (discinesia = 48; sem discinesia = 33) no presente estudo. Uma amostra de sangue foi coletada para avaliar os níveis séricos de AU, a avaliação clínica incluiu os seguintes instrumentos: Avaliação Cognitiva de Montreal (MoCA), Inventário de Depressão de Beck (BDI-II), MDS-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Hoehn and Yahr (HY) e o subitem 4.1 da MDS-UPDRS IV (escore ≥ 1). Informações clínicas relevantes adicionais foram obtidas por meio de um questionário clínico. RESULTADOS: Os níveis séricos de AU foram menores no grupo com discinesia quando comparados ao grupo sem discinesia. O mesmo resultado foi encontrado nos níveis de AU de homens e mulheres. A análise multivariada mostrou que níveis mais baixos de ácido úrico foram significativamente associados a ter discinesia (odds ratio [OR] = 0,424; intervalo de confiança (IC) de 95%: 0,221­0,746; p = 0,005). Análises adicionais verificaram que os níveis séricos de AU estão inversamente correlacionados com sintomas depressivos, duração da doença, MDS-UPDRS IV e tempo gasto com discinesia. Uma correlação positiva foi encontrada com a idade de início dos sintomas da DP. CONCLUSõES: O presente estudo fornece um possível papel dos níveis séricos de AU na LID presente em pacientes com DP.

Effects of Dihydropyridines on the Motor and Cognitive Outcomes of Patients with Parkinson's Disease.

BACKGROUND: Dihydropyridines (DHPs) may have neuroprotective effects against Parkinson's disease (PD). OBJECTIVE: This study investigated the effects of DHPs on nigrostriatal dopaminergic denervation and longitudinal motor and cognitive outcomes in PD. METHODS: We classified 476 patients with drug-naive PD who had undergone dopamine transporter imaging into three groups. They were selected according to a prior diagnosis of hypertension and use of DHPs and were matched using propensity scores: patients without hypertension (HTN-; n = 50) and patients with hypertension treated without DHP (HTN+/DHP-; n = 50) or with DHP (HTN+/DHP+; n = 50). Multiple linear regression and linear mixed model analyses were performed to determine intergroup differences in baseline dopamine transporter availability and longitudinal changes in the levodopa-equivalent dose, respectively. Using Kaplan-Meier analyses, we compared the risks of levodopa-induced dyskinesia, wearing off, and dementia-free survival during the 5.06 years of the mean follow-up period. The Cox regression model determined the independent effects of DHPs on dementia conversion. RESULTS: Dopamine transporter availability in all striatal subregions was comparable between the HTN-, HTN+/DHP-, and HTN+/DHP+ groups. The risks of levodopa-induced dyskinesia and wearing off, as well as longitudinal changes in the levodopa-equivalent dose, did not differ between the groups. The HTN+/DHP+ group had a lower risk of developing dementia than the HTN+/DHP- (Bonferroni-corrected Plog-rank  = 0.036) group. The use of DHP was independently associated with a lower risk of dementia conversion after controlling for other antihypertensive drugs and confounding factors (hazard ratio, 0.242; 95% confidence interval, 0.087-0.668; P = 0.006). CONCLUSIONS: DHPs may be associated with better long-term cognitive outcomes in hypertensive patients with PD. © 2023 International Parkinson and Movement Disorder Society.

Occurrence of involuntary movements after prolonged misuse of zolpidem: a case report.

Zolpidem is a non-benzodiazepine agent used for short-term treatment of insomnia. Several cases of dependence and withdrawal from zolpidem are reported in the literature. Furthermore, involuntary movements after prolonged zolpidem misuse have been described. In this case report, a 69-year-old Italian woman with no history of diagnosed psychiatric or neurologic diseases developed uncontrolled movements and a depressive-anxious syndrome after twelve-year zolpidem misuse. The underlying mechanisms of involuntary movements occurring after long-term zolpidem intake are unknown; yet, we suggest that zolpidem might induce an increase in dopamine release through inhibition of gamma-aminobutyric acid neurons tonically suppressing dopamine cells. Future studies on the occurrence of persistent disorders after long-term benzodiazepine or Z-drug abuse are needed and clinicians should pay attention to the risk of tardive syndromes related to zolpidem misuse, especially in the case of long-term intake of over-therapeutic dosages.

Identifying the therapeutic zone in globus pallidus deep brain stimulation for Parkinson's disease.

OBJECTIVE: The globus pallidus internus (GPI) has been demonstrated to be an effective surgical target for deep brain stimulation (DBS) treatment in patients with medication-refractory Parkinson's disease (PD). The ability of neurosurgeons to define the area of greatest therapeutic benefit within the globus pallidus (GP) may improve clinical outcomes in these patients. The objective of this study was to determine the best DBS therapeutic implantation site within the GP for effective treatment in PD patients. METHODS: The authors performed a retrospective review of 56 patients who underwent bilateral GP DBS implantation at their institution during the period from January 2015 to January 2020. Each implanted contact was anatomically localized. Patients were followed for stimulation programming for at least 6 months. The authors reviewed preoperative and 6-month postsurgery clinical outcomes based on data from the Unified Parkinson's Disease Rating Scale Part III (UPDRS III), dyskinesia scores, and levodopa equivalent daily dose (LEDD). RESULTS: Of the 112 leads implanted, the therapeutic cathode was most frequently located in the lamina between the GPI external segment (GPIe) and the GP externus (GPE) (n = 40). Other common locations included the GPE (n = 24), the GPIe (n = 15), and the lamina between the GPI internal segment (GPIi) and the GPIe (n = 14). In the majority of patients (73%) a monopolar programming configuration was used. At 6 months postsurgery, UPDRS III off medications (OFF) and on stimulation (ON) scores significantly improved (z = -4.02, p < 0.001), as did postsurgery dyskinesia ON scores (z = -4.08, p < 0.001) and postsurgery LEDD (z = -4.7, p < 0.001). CONCLUSIONS: Though the ventral GP (pallidotomy target) has been a commonly used target for GP DBS, a more dorsolateral target may be more effective for neuromodulation strategies. The assessment of therapeutic contact locations performed in this study showed that the lamina between GPI and GPE used in most patients is the optimal central stimulation target. This information should improve preoperative GP targeting.

How resistant are levodopa-resistant axial symptoms? Response of freezing, posture, and voice to increasing levodopa intestinal infusion rates in Parkinson disease.

BACKGROUND AND PURPOSE: Treatment of freezing of gait (FoG) and other Parkinson disease (PD) axial symptoms is challenging. Systematic assessments of axial symptoms at progressively increasing levodopa doses are lacking. We sought to analyze the resistance to high levodopa doses of FoG, posture, speech, and altered gait features presenting in daily-ON therapeutic condition. METHODS: We performed a pre-/postinterventional study including patients treated with levodopa/carbidopa intestinal gel infusion (LCIG) with disabling FoG in daily-ON condition. Patients were evaluated at their usual LCIG infusion rate (T1), and 1 h after 1.5× (T2) and 2× (T3) increase of the LCIG infusion rate by quantitative outcome measures. The number of FoG episodes (primary outcome), posture, speech, and gait features were objectively quantified during a standardized test by a blinded rater. Changes in motor symptoms, dyskinesia, and plasma levodopa concentrations were also analyzed. RESULTS: We evaluated 16 patients with a mean age of 69 ± 9.4 years and treated with LCIG for a mean of 2.2 ± 2.1 years. FoG improved in 83.3% of patients by increasing the levodopa doses. The number of FoG episodes significantly decreased (mean = 2.3 at T1, 1.7 at T2, 1.2 at T3; p = 0.013). Posture and speech features did not show significant changes, whereas stride length (p = 0.049), turn duration (p = 0.001), and turn velocity (p = 0.024) significantly improved on doubling the levodopa infusion rate. CONCLUSIONS: In a short-term evaluation, the increase of LCIG dose can improve "dopa-resistant" FoG and gait issues in most advanced PD patients with overall good control of motor symptoms in the absence of clinically significant dyskinesia.