Comprehensive assessment of levodopa-carbidopa intestinal gel for Turkish advanced Parkinson’s disease patients

Background/aim

Levodopa-carbidopa intestinal gel (LCIG) is an effective treatment modality in the management of advanced Parkinson’s disease (PD) despite frequent adverse events and different rates of dropouts. Efficacy and safety data regarding Turkish patients on LCIG are limited. This study aims to report in detail the efficacy and adverse effect profile of LCIG among advanced PD patients from a Turkish center for movement disorders.

Materials and methods

Twenty-two patients (50% male) who started receiving LCIG between December 2014 and March 2020 were recruited. The efficacy of LCIG was assessed with the Unified Parkinson’s Disease Rating Scale (UPDRS III), Clinical Global İmprovement (CGI) scale, and Quality of Life scale (PDQ8). Improvements in gait disorders and nonmotor features were also questioned. Adverse events (AE) were collated into 3 topics: related to percutaneous endoscopic gastrojejunostomy (PEG-J), device-related, and LCIG infusion-related.

Results

Mean age and pre-LCIG disease duration were 66.7 (8.8) and 13.3 (8.0) years respectively. UPDRS III scores and H-Y scale assessments significantly improved. Better quality of life scores, clinical global improvements, and improvements in dysarthria, dysphagia, and gait were observed. None of our patients dropped out or died during a mean 17.5-month (12.3) period. Overall 20 (90.9%) patients experienced at least one AE. Twelve patients had PEG-J–related complications; three had acute abdomen. Eight (36.4%) patients had device-associated problems. Half of the patients required at least one additional endoscopic procedure and 7 had a device replaced. Mean body weight decreased from 69.5 to 62.5 kg and seven patients had newly onset PNP at a follow-up electromyography. Dyskinesia related to LCIG infusion was observed in 5 (22.7%) patients. There was no significant increase in hallucination among patients.

Conclusion

LCIG is an efficient treatment modality in the management of Turkish patients with advanced Parkinson’s disease. Although most of the patients had at least one AE, none of them dropped out. Patient selection, patient compliance, and collaborative management are important steps affecting the success of modality.

Use of Botulinum Neurotoxin in Parkinson's Disease: A Critical Appraisal

For well over 30 years, the botulinum neurotoxin (BoNT) has been used for a large number of indications, some of which however have not been licensed. Admittedly, approval varies in many countries and this permits a large spectrum for evaluation. Thus, BoNT is used for patients with Parkinson’s disease (PD) and other Parkinson’s syndromes (PS) in varying degrees of frequency. We have to distinguish between (1) indications that are either approved or (2) those not approved, (3) indications that might be a result of PS and (4) finally those which appear independent of PS. The most important indication for BoNT in PS patients is probably sialorrhea, for which approval has been granted in the majority of countries. Cervical dystonia is a frequent symptom in PS, with anterocollis as a specific entity. A further indication is blepharospasm in the different forms, especially the inhibition of eyelid opening in atypical PS. The use of BoNT in cases of camptocormia, the Pisa syndrome and neck rigidity is still a matter of debate. In dystonia of the extremities BoNT can be recommended, especially in dystonia of the feet. One well-known indication, for which however sufficient data are still lacking, involves treating tremor with BoNT. As to autonomic symptoms: Focal hyperhidrosis and detrusor hyperactivity can be mentioned, in this last case BoNT has already been approved. A number of further but rare indications such as freezing-of-gait, dyskinesia, and dysphagia will be discussed and evaluated.

Effects of pedunculopontine nucleus cholinergic lesion on gait and dyskinesia in hemiparkinsonian rats

Pedunculopontine nucleus (PPN) cholinergic neurons are implicated in freezing of gait in Parkinson's disease (PD) and motor stereotypy in normal animals, but the causal role of these neurons on specific gait parameters and treatment-induced dyskinesia remains speculative. Therefore, we examined whether selective cholinergic lesion of the rostral PPN affects PD motor and gait deficits, L-DOPA-induced dyskinesia and motor improvement, and DA-agonist-induced dyskinesia. Sprague-Dawley rats were assigned to one unilaterally lesioned group: Sham lesion, PPN cholinergic lesion with diphtheria urotensin II fusion toxin, medial forebrain bundle dopamine lesion with 6-hydroxydopamine, or dual acetylcholine and dopamine lesion. We used gait analysis and forepaw adjusting steps to examine PD gait and motor deficits. Forepaw adjusting steps were also used to assess motor improvement with L-DOPA treatment. The abnormal involuntary movements scale measured L-DOPA and dopamine D1- and D2-receptor agonist-induced dyskinesia. Lesions, verified via tyrosine hydroxylase and choline acetyltransferase immunohistochemistry reduced an average of 95% of nigral dopamine neurons and 80% of PPN cholinergic neurons, respectively. Rats receiving acetylcholine and dual lesion demonstrated enhanced freezing, and acetylcholine lesioned rats exhibited increased print area and stand index. Dopamine and dual lesion produced similar forepaw adjusting steps task on and off L-DOPA. Relative to DA lesioned rats, dual lesioned rats displayed reduced L-DOPA and DA agonist-induced dyskinesia at specific time points. Our results indicate that PPN cholinergic neurons affect gait parameters related to postural stability. Therefore, therapeutically targeting PPN cholinergic neurons could reduce intractable postural instability in PD without affecting motor benefits or side effects of L-DOPA treatment.

Botulinum Toxin in Movement Disorders: An Update

Since its initial approval in 1989 by the US Food and Drug Administration for the treatment of blepharospasm and other facial spasms, botulinum toxin (BoNT) has evolved into a therapeutic modality for a variety of neurological and non-neurological disorders. With respect to neurologic movement disorders, BoNT has been reported to be effective for the treatment of dystonia, bruxism, tremors, tics, myoclonus, restless legs syndrome, tardive dyskinesia, and a variety of symptoms associated with Parkinson’s disease. More recently, research with BoNT has expanded beyond its use as a powerful muscle relaxant and a peripherally active drug to its potential central nervous system applications in the treatment of neurodegenerative disorders. Although BoNT is the most potent biologic toxin, when it is administered by knowledgeable and experienced clinicians, it is one of the safest therapeutic agents in clinical use. The primary aim of this article is to provide an update on recent advances in BoNT research with a focus on novel applications in the treatment of movement disorders. This comprehensive review of the literature provides a critical review of evidence-based clinical trials and highlights recent innovative pilot studies.

Effects of bilateral subthalamic nucleus deep brain stimulation on motor symptoms in Parkinson's disease: a retrospective cohort study

Deep brain stimulation of the bilateral subthalamic nucleus (STN) is a therapeutic option for patients with Parkinson's disease (PD) in whom medical therapies have been ineffective. This retrospective cohort study analyzed the motor function of 27 patients with advanced PD, from the First Affiliated Hospital of Guangzhou Medical University, China, who received deep brain stimulation of the bilateral subthalamic nucleus and evaluated its therapeutic effects. The 10-year follow-up data of patients was analyzed in Qingyuan People's Hospital, Sixth Affiliated Hospital of Guangzhou Medical University, China. The follow-up data were divided into two categories based on patients during levodopa treatment (on-medication) and without levodopa treatment (off-medication). Compared with baseline, the motor function of on-medication PD patients improved after deep brain stimulation of the bilateral subthalamic nucleus. Even 2 years later, the motor function of off-medication PD patients had improved. On-medication PD patients exhibited better therapeutic effects over the 5 years than off-medication PD patients. On-medication patients' akinesia, speech, postural stability, gait, and cognitive function worsened only after 5 years. These results suggest that the motor function of patients with advanced PD benefitted from treatment with deep brain stimulation of the bilateral subthalamic nucleus over a period up to 5 years. The overall therapeutic effects were more pronounced when levodopa treatment was combined with deep brain stimulation of the bilateral subthalamic nucleus. This study was approved by Institutional Review Board of Qingyuan People's Hospital, The Sixth Affiliated Hospital of Guangzhou Medical University, China (approval No. QPH-IRB-A0140) on January 11, 2018.

Clinician Perspectives of Chronic Pain Management in Children and Adolescents with Cerebral Palsy and Dyskinesia

AIMS

To explore perspectives of clinicians from interdisciplinary teams on the barriers and facilitators to chronic pain management for children and adolescents with cerebral palsy and dyskinesia.

METHODS

Interdisciplinary focus groups (n = 2) were conducted at two Australian tertiary pediatric hospitals. Twenty-five experienced clinicians took part, including ten physiotherapists, six pediatricians, four rehabilitation physicians, four occupational therapists, and one speech and language therapist. An external moderator conducted the focus groups and data were analyzed using inductive thematic analysis.

RESULTS

Four key themes emerged: "balancing the intersection of pain and dyskinesia," "difficulty communicating between so many providers," "uncertainty surrounding chronic pain education," and "differing priorities." Key barriers were identified including a lack of access to some interdisciplinary team members and formalized guidance for health professionals regarding chronic pain education.

CONCLUSION

Key issues were reported to impact the delivery of coordinated inter-disciplinary chronic pain management at the tertiary level for children and adolescents with cerebral palsy and dyskinesia. In the absence of strong evidence, a strategy for implementing effective chronic pain management for children and adolescents with cerebral palsy and dyskinesia and gaining clinician consensus regarding the best practice management are recommended.

Dyskinesia is most centrally situated in an estimated network of extrapyramidal syndrome in Asian patients with schizophrenia: findings from research on Asian psychotropic prescription patterns for antipsychotics

BACKGROUND

Network analysis provides a new viewpoint that explicates intertwined and interrelated symptoms into dynamic causal architectures of symptom clusters. This is a process called 'symptomics' and is concurrently applied to various areas of symptomatology.

AIMS

Using the data from Research on Asian Psychotropic Prescription Patterns for Antipsychotics (REAP-AP), we aimed to estimate a network model of extrapyramidal syndrome in patients with schizophrenia.

METHODS

Using data from REAP-AP, extrapyramidal symptoms of 1046 Asian patients with schizophrenia were evaluated using the nine items of the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). The estimated network of the ordered-categorical DIEPSS items consisted of nodes (symptoms) and edges (interconnections). A community detection algorithm was also used to identify distinctive symptom clusters, and correlation stability coefficients were used to evaluate the centrality stability.

RESULTS

An interpretable level of node strength centrality was ensured with a correlation coefficient. An estimated network of extrapyramidal syndrome showed that 26 (72.2%) of all possible 35 edges were estimated to be greater than zero. Dyskinesia was most centrally situated within the estimated network. In addition, earlier antipsychotic-induced extrapyramidal symptoms were divided into three distinctive clusters - extrapyramidal syndrome without parkinsonism, postural instability and gait difficulty-dominant parkinsonism, and tremor-dominant parkinsonism.

CONCLUSIONS

Our findings showed that dyskinesia is the most central domain in an estimated network structure of extrapyramidal syndrome in Asian patients with schizophrenia. These findings are consistent with the speculation that acute dystonia, akathisia, and parkinsonism could be the risk factors of tardive dyskinesia.

DNM1L-Related Mitochondrial Fission Defects Presenting as Encephalopathy: A Case Report and Literature Review

Background: Mitochondrial dynamics, including mitochondrial fission and fusion, transport and distribution, biogenesis and degradation, are critical to neuronal function. The dynamin-1 like (DNM1L) gene encodes dynamin-related protein 1 (DRP1/DLP1), which is an evolutionarily conserved member of the dynamin family and is responsible for mitochondrial division. DNM1L variants can lead to mitochondrial fission dysfunction and neurological disorders. Methods: We report a case of DNM1L-related mitochondrial disease admitted to Tianjin Children's Hospital. We searched for similar reported cases in the PubMed database using the terms "DNM1L" and "mitochondrial," reviewed recent literature to summarize the clinical and genetic characteristics, and analyzed genotype-phenotype correlations. Results: The patient presented with psychomotor retardation, motor disturbance (muscle weakness with paroxysmal hypermyotonia), and a de novo variant (c.116G>A, g.22229G>A, p.S39N) in the GTPase domain of DNM1L (reference sequence NM_012062), which has not previously been reported in the literature. This case was combined with an additional 35 cases identified in 20 relevant references in order to analyze a total of 36 patients. The male-to-female ratio was 1:1.06, and the median age of onset was 6 months (range, neonatal period to 9 years). The cardinal symptoms included psychomotor retardation in 77.8% (28/36), limb paralysis in 66.7% (18/27), dystonia in 82.8% (24/29), and epilepsy in 59.4% (19/32). The clinical manifestations of variants in the GTPase domain of DRP1 were milder than those identified in the middle domain. Conclusion: This case report describes a new variant of the DNM1L gene, and summarizes previously reported cases. Furthermore, the clinical phenotype and the genotype of DNM1L gene-associated mitochondrial disease was analyzed to improve the understanding of this disease.

Prevalence and Risk Factors for Malnutrition in Patients With Parkinson's Disease

Objectives: This study aimed to investigate the relationship between nutritional status and Parkinson's disease (PD) features.

Methods: The cohort was composed of 556 Parkinson's patients who were admitted to the hospital. Patients were categorized as normal nutrition or at risk of malnutrition/already malnourished. Questionnaires, physical examinations, and biochemical tests were conducted. The relationship between nutrition status and PD was analyzed using t-tests, χ²-tests, and logistic regression models.

Results: The prevalence of malnutrition [defined as a Mini Nutritional Assessment (MNA) score <17] was 39.2%, and 30.3% of patients were at risk of malnutrition (17 ≤ MNA score ≤ 23.5). There was no difference in gender and age between the different nutrition groups (P < 0.05). Patients at risk of malnutrition and those who were malnourished had a longer course of disease, more severe motor symptoms, a higher stage of PD according to the Hoehn and Yahr (H-Y) classification, a lower body mass index (BMI) index, a lower cognitive score, higher levels of depression and anxiety, and more serious non-motor symptoms (P < 0.05) than patients with normal nutrition. There were differences in adenosine deaminase, albumin, phosphorus, chlorine, total protein, and uric acid between the two groups (P < 0.05). High Unified PD Rating Scale (UPDRS-III) scores, high H-Y stages, and dyskinesia were risk factors for malnutrition in PD patients, while high levels of total protein, uric acid, and chlorine were protective factors that led to good nutrition (P < 0.05).

Conclusions: Our results showed that dyskinesia, disease severity, total protein levels, uric acid levels, and chlorine levels were associated with nutritional status among Chinese PD patients. The findings of this study indicate the significance of the early detection and prevention of malnutrition to improve the quality of life of PD patients.

Left atrial wall dyskinesia assessed during contractile phase as a predictor of atrial fibrillation recurrence after electrical cardioversion performed due to persistent atrial fibrillation

Direct current cardioversion (DCCV) is one of the basic methods for restoring sinus rhythm (SR) in patients with atrial fibrillation (AF). Left atrial (LA) strain is one of the parameters used to assess the risk of AF recurrence following DCCV. Assessing the strain also allows for the detection of segmental disorders of LA wall contractility, including dispersion or dyskinesia. In the present study, we determined the predictive value of LA wall dyskinesia in assessing the risk of AF recurrence after DCCV. We performed a comprehensive echocardiography in 89 patients with persistent AF following successful DCCV. We assessed the strain and strain rate in the reservoir (r), conduit, and contractile (ct) phases by using speckle tracking echocardiography. Dyskinesia was diagnosed when the strain rate of any segment of the LA wall displayed positive values during contraction. After 12 months, 47.2% of patients maintained SR. Patients who maintained SR had a significantly lower LA strain (LAS)r assessed in the apical 4-chamber view (4c) (11.38 ± 4.63 vs 14.54 ± 5.11; P = .004) and 2-chamber view (2c) (11.05 ± 4.1 vs 14.93 ± 6.82%; P = .006), LASct4c (2.51 ± 2.3 vs 5.09 ± 3.29%; P < .001), LASct2c (3.6 ± 2.98 vs 5.67 ± 4.23%; P = .008), peak strain rate (pLASR) ct4c (0.36 ± 0.24 s vs 0.62 ± 0.4; P < .001) and pLASRct2c (0.49 ± 0.30 vs 0.79 ± 0.53 s; P = .01). LA dyskinesia was observed less frequently in the 4c view in patients who maintained SR (59.57 vs 17.5%; P < .001). Multivariable logistic regression showed that the LASct4c (odds ratio (OR) 0.78; 95%CI 0.63-0.97; P = .027) and LA dyskinesia observed in the 4c view (OR 3.53; 95%CI 1.16-10.76; P = .027) were significant independent predictors of AF recurrence at 12 months. We conclude that LA dyskinesia observed in the 4c view and LASct4c are independent risk factors for AF recurrence following DCCV.

Levodopa-Induced Dyskinesia Are Mediated by Cortical Gamma Oscillations in Experimental Parkinsonism

BACKGROUND

Levodopa is the most efficacious drug in the symptomatic therapy of motor symptoms in Parkinson's disease (PD); however, long-term treatment is often complicated by troublesome levodopa-induced dyskinesia (LID). Recent evidence suggests that LID might be related to increased cortical gamma oscillations.

OBJECTIVE

The objective of this study was to test the hypothesis that cortical high-gamma network activity relates to LID in the 6-hydroxydopamine model and to identify new biomarkers for adaptive deep brain stimulation (DBS) therapy in PD.

METHODS

We recorded and analyzed primary motor cortex (M1) electrocorticogram data and motor behavior in freely moving 6-OHDA lesioned rats before and during a daily treatment with levodopa for 3 weeks. The results were correlated with the abnormal involuntary movement score (AIMS) and used for generalized linear modeling (GLM).

RESULTS

Levodopa reverted motor impairment, suppressed beta activity, and, with repeated administration, led to a progressive enhancement of LID. Concurrently, we observed a highly significant stepwise amplitude increase in finely tuned gamma (FTG) activity and gamma centroid frequency. Whereas AIMS and FTG reached their maximum after the 4th injection and remained on a stable plateau thereafter, the centroid frequency of the FTG power continued to increase thereafter. Among the analyzed gamma activity parameters, the fraction of longest gamma bursts showed the strongest correlation with AIMS. Using a GLM, it was possible to accurately predict AIMS from cortical recordings.

CONCLUSIONS

FTG activity is tightly linked to LID and should be studied as a biomarker for adaptive DBS. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

MR-guided focused ultrasound pallidotomy for Parkinson's disease: safety and feasibility

OBJECTIVE

Stereotactic radiofrequency pallidotomy has demonstrated improvement in motor fluctuations in patients with Parkinson's disease (PD), particularly levodopa (L-dopa)-induced dyskinesias. The authors aimed to determine whether or not unilateral pallidotomy with MR-guided focused ultrasound (MRgFUS) could safely improve Unified Dyskinesia Rating Scale (UDysRS; the primary outcome measure) scores over baseline scores in patients with PD.

METHODS

Twenty patients with PD and L-dopa responsiveness, asymmetrical motor signs, and motor fluctuations, including dyskinesias, participated in a 1-year multicenter open-label trial of unilateral MRgFUS ablation of the globus pallidus internus.

RESULTS

The sonication procedure was successfully completed in all 20 enrolled patients. MRgFUS-related adverse neurological events were generally mild and transient, including visual field deficit (n = 1), dysarthria (n = 4, 2 mild and 2 moderate), cognitive disturbance (n = 1), fine motor deficit (n = 2), and facial weakness (n = 1). Although 3 adverse events (AEs) were rated as severe (transient sonication-related pain in 2, nausea/vomiting in 1), no AE fulfilled US FDA criteria for a Serious Adverse Effect. Total UDysRS, the primary outcome measure, improved 59% after treatment (baseline mean score 36.1, 95% CI 4.88; at 3 months 14.2, 95% CI 5.72, p < 0.0001), which was sustained throughout the study (at 12 months 20.5, 95% CI 7.39, 43% improvement, p < 0.0001). The severity of motor signs on the treated side (Movement Disorder Society version of the United Parkinson's Disease Rating Scale [MDS-UPDRS] part III) in the "off" medication state also significantly improved (baseline mean score 20.0, 95% CI 2.4; at 3 months 10.6, 95% CI 1.86, 44.5% improvement, p < 0.0001; at 12 months 10.4, 95% CI 2.11, 45.2% improvement, p > 0.0001). The vast majority of patients showed a clinically meaningful level of improvement on the impairment component of the UDysRS or the motor component of the UPDRS, while 1 patient showed clinically meaningful worsening on the UPDRS at month 3.

CONCLUSIONS

This study supports the feasibility and preliminary efficacy of MRgFUS pallidotomy in the treatment of patients with PD and motor fluctuations, including dyskinesias. These preliminary data support continued investigation, and a placebo-controlled, blinded trial is in progress. Clinical trial registration no.: NCT02263885 (clinicaltrials.gov).

Imepitoin for treatment of idiopathic head tremor syndrome in dogs: A randomized, blinded, placebo-controlled study

Background

Idiopathic head tremor syndrome is a paroxysmal movement disorder of unknown etiology. Spontaneous remission may occur, but owners may request treatment in severely affected dogs with continued episodes. Controlled studies of the disease are not available.

Hypothesis/Objectives

A drug with gamma amino butyric acid‐ergic and anxiolytic effects will decrease head tremor episodes.

Animals

Twenty‐four dogs with severe nonremitting head tremor and presumptive clinical diagnosis of idiopathic head tremor syndrome.

Methods

Prospective, blinded, placebo‐controlled clinical trial to compare imepitoin with placebo in dogs with frequent episodes of idiopathic head tremor. Evaluation of efficacy used the quotient T2/T1 that represented prolongation of the head tremor‐free period compared to a 3‐month baseline. A dog was considered a responder if tremors subsided or if the head tremor‐free period was 3× longer than the longest period during baseline (T2/T1 ≥ 3). Sample size calculations considered a large effect of imepitoin on T2/T1 (Cohen's d = 0.8).

Results

There were no responders in the placebo group (0/12). In the imepitoin group, the responder rate was 17% (2/12; P = .18) with T2/T1 3.8 and 4.0. Mean T2/T1 was 1.0 ± 1.4 in the imepitoin and 0.4 ± 0.4 in the placebo group (P = .37).

Conclusion and Clinical Importance

Imepitoin did not result in a significant overall benefit. Future studies should focus on treatment of subgroups with a common pathophysiology and similar comorbidities.

Serotonergic System Impacts Levodopa Response in Early Parkinson's and Future Risk of Dyskinesia

BACKGROUND

The serotonergic system is known to contribute to levodopa-derived dopamine release in advanced Parkinson's disease.

OBJECTIVE

We investigated the role of the serotonergic system in determining response to treatment in early disease and risk for complications concurrently with dopaminergic alterations.

METHODS

Eighteen patients with early and stable Parkinson's disease underwent multitracer positron emission tomography using [¹¹ C]dihydrotetrabenazine (vesicular monoamine transporter 2 marker), [¹¹ C]methylphenidate (dopamine transporter marker), [¹¹ C]-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile (DASB, serotonin transporter marker), and [¹¹ C]raclopride (D2 marker) to investigate relationships between striatal dopaminergic and serotonergic alterations and levodopa-induced dopamine release, related to motor response to treatment and risk for dyskinesias, using a novel joint pattern analysis.

RESULTS

The joint pattern analysis revealed correlated spatial patterns conceptually related to abnormal dopamine turnover in the putamen (higher dopamine release associated with dopaminergic and serotonergic denervation); response to treatment significantly inversely correlated with turnover-related dopamine release (P < 10^-5 ). Patterns identified without inclusion of the DASB data showed no correlation with clinical data, indicating an important contribution from the serotonergic system to a clinically relevant abnormal dopamine release in early disease. Subjects who experienced dyskinesia 3 years after baseline scans showed higher turnover-related dopamine release compared with subjects who remained stable (P < 0.01).

CONCLUSIONS

Joint analysis of dopaminergic and serotonergic data identified a turnover-related dopamine release component, strongly related to motor response to levodopa in early disease and contributing to higher risk for dyskinesia. These findings suggest that the contribution of the serotonergic system to dopamine release not only increases the risk for motor complications but also fails to provide sustained therapeutic advantage in early disease. © 2020 International Parkinson and Movement Disorder Society.

Paroxysmal Symptoms in Multiple Sclerosis-A Review of the Literature

Paroxysmal symptoms are well-recognized manifestations of multiple sclerosis (MS). These are characterized by multiple, brief, sudden onset, and stereotyped episodes. They manifest as motor, sensory, visual, brainstem, and autonomic symptoms. When occurring in the setting of an established MS, the diagnosis is relatively straightforward. Conversely, the diagnosis is significantly more challenging when they occur as the initial manifestation of MS. The aim of this review is to summarize the various forms of paroxysmal symptoms reported in MS, with emphasis on the clinical features, radiological findings and treatment options.

Stimulation-Induced Dyskinesia After Subthalamic Nucleus Deep Brain Stimulation in Patients With Meige Syndrome

OBJECTIVES

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is increasingly used to treat Meige syndrome (MS) and markedly improves symptoms. Stimulation-induced dyskinesia (SID), which adversely affects surgical outcomes and patient satisfaction, may, however, occur in some patients. This study attempts to explore possible causes of SID.

MATERIALS AND METHODS

Retrospectively collected clinical data on 32 patients who underwent STN-DBS between October 2016 and April 2019 were analyzed. Clinical outcomes were assessed pre- and post-surgery, using the Burke-Fahn-Marsden dystonia rating scale (BFMDRS). Patients were divided into a dyskinesia group and a non-dyskinesia group, according to whether or not they experienced persistent SID during follow-up. The coordinates of the active contacts were calculated from post-operative computerized tomography or magnetic resonance imaging, using the inter-commissural line as a reference. At final follow-up, the main stimulatory parameters for further study included pulse width, voltage, and frequency.

RESULTS

At final follow-up (mean = 16.3 ± 7.2 months), MS patients had improved BFMDRS total scores compared with pre-surgical scores (mean improvement = 79.0%, p < 0.0001). The mean improvement in BFMDRS total scores in the dyskinesia (n = 10) and non-dyskinesia (n = 22) groups were 81.6 ± 8.8% and 77.9 ± 14.2%, respectively. The mean minimum voltage to induce dyskinesia was 1.7 ± 0.3 V. The programmed parameters of both groups were similar. When compared with the non-dyskinesia group, active stimulatory contact coordinates in the dyskinesia group were inferior (mean left side: z = -2.3 ± 1.7 mm vs. z = -1.2 ± 1.5 mm; p = 0.0282; mean right side: z = -2.7 ± 1.9 mm vs. z = -2.3 ± 1.7 mm; p = 0.0256). The x and y coordinates were similar.

CONCLUSION

STN-DBS is an effective intervention for MS, providing marked improvements in clinical symptoms; SID may, however occur in the subsequent programming control process. Comparing patients with/without dyskinesia, the active contacts were located closer to the inferior part of the STN in patients with dyskinesia, which may provide an explanation for the dyskinesia.

Paroxysmal Cranial Dyskinesia and Nail-Patella Syndrome Caused by a Novel Variant in the LMX1B Gene

BACKGROUND

In a Danish family, multiple individuals in five generations present with early-onset paroxysmal cranial dyskinesia, musculoskeletal abnormalities, and kidney dysfunction.

OBJECTIVE

To demonstrate linkage and to identify the underlying genetic cause of disease.

METHODS

Genome-wide single-nucleotide polymorphisms analysis, Sequence-Tagged-Site marker analyses, exome sequencing, and Sanger sequencing were performed.

RESULTS

Linkage analyses identified a candidate locus on chromosome 9. Exome sequencing revealed a novel variant in LMX1B present in all affected individuals, logarithm of the odds (LOD) score of z = 6.54, predicted to be damaging. Nail-patella syndrome (NPS) is caused by pathogenic variants in LMX1B encoding a transcription factor essential to cytoskeletal and kidney growth and dopaminergic and serotonergic network development. NPS is characterized by abnormal musculoskeletal features and kidney dysfunction. Movement disorders have not previously been associated with NPS.

CONCLUSIONS

Paroxysmal dyskinesia is a heretofore unrecognized feature of the NPS spectrum. The pathogenic mechanism might relate to aberrant dopaminergic circuits. © 2020 International Parkinson and Movement Disorder Society.

Levodopa/Carbidopa Intestinal Gel Long-Term Outcome in Parkinson's Disease: Focus on Dyskinesia

Background

Levodopa-carbidopa intestinal gel (LCIG) treatment has shown variable effect on dyskinesia in Parkinson's disease (PD).

Objective

To identify PD patients who are likely to have troublesome dyskinesia under LCIG treatment and describe the pharmacokinetic-dynamic profile and dyskinesia phenomenology of those patients.

Methods

PD patients were assessed for clinical and therapeutic variables, before LCIG treatment (T0) and at last outpatient visit (T1). Sub-groups of patients with and without "troublesome dyskinesia" (UPDRS IV, item 33 ≥2), matched for disease and LCIG treatment duration, underwent a pharmacokinetic-dynamic assessment.

Results

We included 53 PD patients. After a mean of 51.7 ± 34.1 months of LCIG treatment, "off-time" was significantly reduced, whereas, dyskinesia duration/disability did not change. The multivariate regression model, adjusted for LCIG treatment duration, showed that being female increases the risk of presenting troublesome dyskinesia at T1 (odds ratio [OR] = 9.2; 95% confidence interval [CI] = 2.4-37.4) that was also significantly associated to longer off periods at T1 (OR= 4.4; 95% CI = 1.1-14.3). Female patients showed a higher risk for a higher dyskinesia score at T1 (sum of the items 32 and 33: P = 0.001). Patients with troublesome dyskinesia showed a tendency for a lower motor benefit and the appearance of more severe dyskinesia despite similar levodopa plasma concentration.

Conclusion

Dyskinesia should be carefully monitored in patients undergoing LCIG, with particular caution for female patients. Whether combined clinical and pharmacodynamic assessments could be helpful to manage patients with troublesome dyskinesia under LCIG treatment needs further evaluation in a larger group of patients.

Efficacy of Istradefylline for the Treatment of ADCY5-Related Disease

View Supplementary Video 1 View Supplementary Video 2.

Application of the '5-2-1' screening criteria in advanced Parkinson's disease: interim analysis of DUOGLOBE

Aim: A Delphi expert consensus panel proposed that fulfilling ≥1 of the '5-2-1 criteria' (≥five-times daily oral levodopa use, ≥two daily hours with 'Off' symptoms or ≥one daily hour with troublesome dyskinesia) suggests advanced Parkinson's disease (PD). Patients & methods: DUOdopa/Duopa in Patients with Advanced PD - a GLobal OBservational Study Evaluating Long-Term Effectiveness (DUOGLOBE) - is a single-arm, postmarketing, observational, long-term effectiveness study of levodopa-carbidopa intestinal gel (LCIG) for advanced PD. Results: This 6-month interim analysis (n = 139) affirms that most (98%) enrolled patients fulfill ≥1 of the 5-2-1 criteria. These patients responded favorably to LCIG treatment. Safety was consistent with other LCIG studies. Conclusion: In advanced PD patients, the 5-2-1 criteria generally aligns with clinician assessment. Clinical Trial Registration: NCT02611713 (ClinicalTrials.gov).

Lacosamide-Induced Dyskinesia in Children With Intractable Epilepsy

Lacosamide, an antiepileptic drug prescribed for children with refractory focal epilepsy, is generally well tolerated, with dose-dependent adverse effects. We describe 4 children who developed a movement disorder in conjunction with the initiation and/or uptitration of lacosamide. Three patients developed dyskinesias involving the face or upper extremity whereas the fourth had substantial worsening of chronic facial tics. The patients all had histories suggestive of opercular dysfunction: 3 had seizure semiologies including hypersalivation, facial and upper extremity clonus while the fourth underwent resection of polymicrogyria involving the opercula. Onset, severity, and resolution of dyskinesias correlated with lacosamide dosing. These cases suggest that pediatric patients with dysfunction of the opercular cortex are at increased risk for developing drug-induced dyskinesias on high-dose lacosamide therapy. Practitioners should be aware of this potential side effect and consider weaning lacosamide or video electroencephalography (EEG) for differential diagnosis, particularly in pediatric patients with underlying opercular dysfunction.

ATP Signaling Controlling Dyskinesia Through P2X7 Receptors

Dopamine replacement therapy with L-3,4-dihydroxyphenylalanine (L-DOPA) is the only temporary therapy for Parkinson's disease (PD), but it triggers dyskinesia over time. Since dyskinesia is associated with increased neuronal firing that bolsters purinergic signaling, we now tested whether the selective and blood-brain barrier-permeable P2X7 receptor antagonist Brilliant Blue-G (BBG, 22.5-45 mg/kg ip) attenuated behavioral, neurochemical and biochemical alterations in rats turned hemiparkinsonian upon unilateral striatal injection of 6-hydroxydopamine (6-OHDA) and treated daily with L-DOPA (30 mg/kg by gavage) for 22 days. The blockade of P2X7 receptors decreased L-DOPA-induced dyskinesia and motor incoordination in hemiparkinsonian rats. In parallel, BBG treatment rebalanced the altered dopamine D1 and D2 receptor density and signaling as well as some neuroinflammation-associated parameters in the striatum and substantia nigra. These findings herald a hitherto unrecognized role for purinergic signaling in the etiopathology of dyskinesia and prompt P2X7 receptor antagonists as novel candidate anti-dyskinesia drugs.

µ Opioid Receptor Agonism for L-DOPA-Induced Dyskinesia in Parkinson's Disease

Parkinson's disease (PD) is characterized by severe locomotor deficits and is commonly treated with the dopamine precursor L-DOPA, but its prolonged usage causes dyskinesias referred to as L-DOPA-induced dyskinesia (LID). Several studies in animal models of PD have suggested that dyskinesias are associated with a heightened opioid cotransmitter tone, observations that have led to the notion of a LID-related hyperactive opioid transmission that should be corrected by µ opioid receptor antagonists. Reports that both antagonists and agonists of the µ opioid receptor may alleviate LID severity in primate models of PD and LID, together with the failure of nonspecific antagonist to improve LID in pilot clinical trials in patients, raises doubt about the reliability of the available data on the opioid system in PD and LID. After in vitro characterization of the functional activity at the µ opioid receptor, we selected prototypical agonists, antagonists, and partial agonists at the µ opioid receptor. We then showed that both oral and discrete intracerebral administration of a µ receptor agonist, but not of an antagonist as long thought, ameliorated LIDs in the gold-standard bilateral 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned female macaque model of PD and LID. The results call for a reappraisal of opioid pharmacology in the basal ganglia as well as for the development of brain nucleus-targeted µ opioid receptor agonists.SIGNIFICANCE STATEMENT µ opioid receptors have long been considered as a viable target for alleviating the severity of L-DOPA-induced hyperkinetic side effects, induced by the chronic treatment of Parkinson's disease motor symptoms with L-DOPA. Conflicting results between experimental parkinsonism and Parkinson's disease patients, however, dampened the enthusiasm for the target. Here we reappraise the pharmacology and then demonstrate that both oral and discrete intracerebral administration of a µ receptor agonist, but not of an antagonist as long thought, ameliorates LIDs in the gold-standard bilateral 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned macaque model of Parkinson's disease, calling for a reappraisal of the opioid pharmacology as well as for the development of brain nucleus-targeted µ receptor agonists.

HOTAIR Accelerates Dyskinesia in a MPTP-Lesioned Mouse Model of PD via SSTR1 Methylation-Mediated ERK1/2 Axis

Homeobox transcript antisense RNA (HOTAIR), has been associated with neuroprotective effects in Parkinson's disease (PD). However, the underlying mechanisms still remain unclear. Hence, this present study attempted to clarify the functional relevance of HOTAIR in PD. We established an in vivo mouse model of PD using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and an in vitro cell model of PD by treating dopaminergic neuron MN9D cells with 1-methyl-4-phenylpyridinium species (MPP+). The expressions of somatostatin receptor 1 (SSTR1) and HOTAIR were altered to examine their effects on MN9D cell viability and apoptosis, as well as on movement impairments in MPTP-induced PD mouse model. The results indicated that HOTAIR expression was upregulated and SSTR1 was downregulated in in vivo and in vitro PD models. HOTAIR could bind to the promoter region of SSTR1, resulting in an increase of SSTR1 methylation through the recruitment of DNA methyltransferases in PD cell models. Notably, overexpression of HOTAIR and silencing of SSTR1 enhanced dopaminergic neuron apoptosis in MN9D cells and exacerbated dyskinesia in MPTP-induced PD mouse model. Collectively, overexpressed HOTAIR stimulates DNA methylation of SSTR1 to reduce SSTR1 expression, thereby accelerating dyskinesia and facilitating dopaminergic neuron apoptosis in a MPTP-lesioned PD mouse model via activation of the ERK1/2 axis.