Motor Complications in Parkinson's Disease: Results from 3343 Patients Followed for up to 12 Years

BACKGROUND

Motor complications are well recognized in Parkinson's disease (PD), but their reported prevalence varies and functional impact has not been well studied.

OBJECTIVES

To quantify the presence, severity, impact and associated factors for motor complications in PD.

METHODS

Analysis of three large prospective cohort studies of recent-onset PD patients followed for up to 12 years. The MDS-UPDRS part 4 assessed motor complications and multivariable logistic regression tested for associations. Genetic risk score (GRS) for Parkinson's was calculated from 79 single nucleotide polymorphisms.

RESULTS

3343 cases were included (64.7% male). Off periods affected 35.0% (95% CI 33.0, 37.0) at 4-6 years and 59.0% (55.6, 62.3) at 8-10 years. Dyskinesia affected 18.5% (95% CI 16.9, 20.2) at 4-6 years and 42.1% (38.7, 45.5) at 8-10 years. Dystonia affected 13.4% (12.1, 14.9) at 4-6 years and 22.8% (20.1, 25.9) at 8-10 years. Off periods consistently caused greater functional impact than dyskinesia. Motor complications were more common among those with higher drug doses, younger age at diagnosis, female gender, and greater dopaminergic responsiveness (in challenge tests), with associations emerging 2-4 years post-diagnosis. Higher Parkinson's GRS was associated with early dyskinesia (0.026 ≤ P ≤ 0.050 from 2 to 6 years).

CONCLUSIONS

Off periods are more common and cause greater functional impairment than dyskinesia. We confirm previously reported associations between motor complications with several demographic and medication factors. Greater dopaminergic responsiveness and a higher genetic risk score are two novel and significant independent risk factors for the development of motor complications.

The Parkinson's Story of a Neurologist with 32 Years of Experience on Parkinson's Disease

As a neurologist who has followed up countless Parkinson's patients over the last 32 years of my fifty-year career; I denied diagnosing myself with Parkinson's disease (PD), although the seldom mild involuntary "twitches" that occurred in the thumb of my right hand over a two-year period, resembled Parkinson's disease tremor. However, when these involuntary contractions became persistent; considering its similarity to characteristic resting tremor in typical PD, the positive effect of dopaminergic medications, the development of levodopa-induced dyskinesias and other non-motor symptoms, it was clear that the PD diagnosis was accurate. This situation naturally caused me anxiety, and for a year and a half, I kept my diagnosis hidden from everyone except a few close relatives. However, with the encouragement of a psychiatrist friend, when I was able to share my condition with my loved ones, I felt a relative reduction in the burden I was carrying and consequently experienced emotional relief. I am still able to carry out my daily activities independently with a rather low dose of medication, and my PD symptoms do not attract noticeable attention.

Situs Inversus Totalis in a Newborn With Primary Ciliary Dyskinesia

Respiratory distress in the newborn is associated with numerous etiologies, some common and some rare. When respiratory distress is accompanied by laterality defects, namely, situs inversus (SI), the index of suspicion for comorbid primary ciliary dyskinesia (PCD) should be raised. Primary ciliary dyskinesia is characterized by ciliary dysmotility and the accumulation of thick secretions in the airways that obstruct air and gas exchange. Neonatal clinicians should know that while PCD is definitively diagnosed in infancy or early childhood, findings suspicious for PCD should be communicated to primary care providers at discharge from the hospital to facilitate timely subspecialty involvement, diagnosis, and treatment. This article will present a case report of a term newborn with SI totalis who was later diagnosed with PCD. We will discuss epidemiology, pathophysiology, clinical manifestations, and diagnostics, followed by management strategies. Additionally, we discuss the outpatient needs and lifespan implications.

Retrospective Investigation and Research on Fall Events Among Hospitalized Patients in the Rehabilitation Department

Objective

We investigated the clinical characteristics, fall outcomes, and related factors of falls in patients who were hospitalized in the rehabilitation department, and explored strategies to reduce the incidence of falls and prevent falls in patients.

Methods

Data from 60 patients who fell in the rehabilitation department between 2016 and 2021 were analyzed for clinical characteristics, associated factors, incidence of falls, injuries, and patient demographics. Under the random stratified sampling method, 60 patients who did not fall during the same period were selected as the control group, and relevant data was collected. Measurement data were compared using an independent sample t-test. Enumeration data were compared using chi-squared (χ2) test was employed to compare these data between the two groups. Non-parametric data were analyzed using the Mann-Whitney U-test. Factors potentially influencing falls were scrutinized through both univariate and binary logistic regression analyses.

Results

The median annual incidence of falls among patients who were hospitalized in the rehabilitation department was 0.04%, while the overall fall injury rate was 60%. Falls were most prevalent within 30 days of hospitalization (71.67%). The most common fall-related condition was craniocerebral disease (83.33%). The incidents of falls location of fall were mainly reported in nearby areas of rehabilitation ward (70%). Most accidents occurred between 7:00 a.m.-12:00 p.m. and 3:01 p.m.-6:00 p.m. (63.33%), and dyskinesia was the most common cause of falls (71.67%). There were 39 patients (65.00%) with Barthel Index (BI) scores ranging between 40-60.

Conclusion

Patients in the rehabilitation department had a greater incidence of falls and fall injuries. Within 30 days of admission, patients with moderately dependent craniocerebral disorders and dyskinesia frequently experienced falls during typical daytime shifts in areas characterized by endemic conditions.

A proof of concept: digital diary using 24-hour monitoring using wearable device for patients with Parkinson's disease in nursing homes

Introduction

In the advanced stages of Parkinson's disease (PD), motor complications such as wearing-off and dyskinesia are problematic and vary daily. These symptoms need to be monitored precisely to provide adequate care for patients with advanced PD.

Methods

This study used wearable devices to explore biomarkers for motor complications by measuring multiple biomarkers in patients with PD residing in facilities and combining them with lifestyle and clinical assessments. Data on the pulse rate and activity index (metabolic equivalents) were collected from 12 patients over 30 days.

Results

The pulse rate and activity index during the off- and on-periods and dyskinesia were analyzed for two participants; the pulse rate and activity index did not show any particular trend in each participant; however, the pulse rate/activity index was significantly greater in the off-state compared to that in the dyskinesia and on-states, and this index in the dyskinesia state was significantly greater than that in the on-state in both participants.

Conclusion

These results suggest the pulse rate and activity index combination would be a useful indicator of wearing-off and dyskinesia and that biometric information from wearable devices may function as a digital diary. Accumulating more cases and collecting additional data are necessary to verify our findings.

Japanese Mucuna pruriens (Hasshou beans) Showed Fast-acting and Long-lasting Effects in Parkinson's Disease

Objective Mucuna pruriens (MP) is a legume whose seeds contain levodopa (LD), which has potential therapeutic effects against Parkinson's disease (PD). However, further research is needed to thoroughly evaluate its efficacy and safety for treating this condition. In this study, we analyzed the pharmacokinetics of MP grown in Japan and investigated its mechanism of action in PD. Methods MP seeds ground after roasting (containing 4.02% LD per MP powder) were used as the reagent and compared with an equivalent LD/carbidopa (CD) preparation. This clinical trial was conducted using a crossover design among PD patients attending our institution. Each patient received a single dose of 100/10 mg LD/CD tablets and 11 g of MP reagent. Results Among the seven patients with PD, MP prolonged the ON time 2-fold compared to LD/CD. The LD concentrations after MP intake were higher than those after LD/CD intake, whereas dyskinesia did not increase. An analysis of the LD metabolites showed that the 3-O-methyl-dopa/LD metabolic ratio was significantly lower after MP ingestion than after LD/CD ingestion, indicating that MP has a catechol-O-methyl transferase inhibitory effect. Conclusions This is the first report of a pharmacokinetic analysis conducted on actual patients with PD showing that MP significantly prolongs the ON time. The advantages of MP as a treatment for PD have been confirmed: it is inexpensive, as effective as LD, works faster and longer than LD, and does not increase dyskinesia.

Buspirone and Zolmitriptan Combination for Dyskinesia: A Randomized, Controlled, Crossover Study

BACKGROUND

Preclinical evidence suggests that co-administration of the 5-HT1A agonist buspirone and the 5-HT1B/1D agonist zolmitriptan act synergistically to reduce dyskinesia to a greater extent than that achieved by either drug alone.

OBJECTIVES

Assess the therapeutic potential of a fixed-dose buspirone and zolmitriptan combination in Parkinson's disease (PD) patients with levodopa-induced dyskinesia.

METHODS

Single-center, randomized, placebo-controlled, two-way crossover study (NCT02439203) of a fixed-dose buspirone/zolmitriptan regimen (10/1.25 mg three times a day) in 30 patients with PD experiencing at least moderately disabling peak-effect dyskinesia.

RESULTS

Seven days of treatment with buspirone/zolmitriptan added to levodopa significantly reduced dyskinesia as assessed by Abnormal Involuntary Movement Scale scores versus placebo (mean treatment effect vs. placebo: -4.2 [-6.1, -2.3]) without significantly worsening Unified Parkinson's Disease Rating Scale (UPDRS) Part III (ON) scores (mean treatment effect vs. placebo: 0.6 [-0.1, 1.3]). No serious adverse events were reported.

CONCLUSIONS

In this proof-of-concept study, addition of buspirone/zolmitriptan to the patients' PD medication regimen significantly reduced dyskinesia severity without worsening motor function. © 2024 International Parkinson and Movement Disorder Society.

The 5-HT2A/2C inverse agonist nelotanserin alleviates L-DOPA-induced dyskinesia in the MPTP-lesioned marmoset

Nelotanserin is a serotonin 2A and 2C (5-HT2A/2C) inverse agonist that was previously tested in the clinic for rapid-eye movement sleep behaviour disorder and psychosis in patients with Parkinson's disease (PD) dementia. Its effect on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia has however not been investigated. As 5-HT2A antagonism/inverse agonism is a validated approach to alleviate dyskinesia, we undertook the current study to evaluate the anti-dyskinetic potential of nelotanserin in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned marmoset. Parkinsonism was induced in six common marmosets (Callithrix jacchus, three females and three males) that were then chronically treated with L-DOPA to induce dyskinesia. On experimental days, they were administered L-DOPA in combination with vehicle or nelotanserin (0.1, 0.3 and 1 mg/kg) subcutaneously, in a randomised fashion. Dyskinesia and parkinsonism were rated post hoc by a blinded observer. In comparison to vehicle, the addition of nelotanserin 0.3 and 1 mg/kg to L-DOPA diminished peak dose dyskinesia by 47% (P < 0.05) and 69% (P < 0.001). Nelotanserin 0.3 and 1 mg/kg also reduced the severity of global dyskinesia, by 40% (P < 0.01) and 55% (P < 0.001), when compared to vehicle. Nelotanserin 0.1 mg/kg did not alleviate peak dose or global dyskinesia severity. Nelotanserin had no impact on the anti-parkinsonian action of L-DOPA. Our results highlight that nelotanserin may represent an efficacious anti-dyskinetic drug and provide incremental evidence of the potential benefit of 5-HT2A/2C antagonism/inverse agonism for drug-induced dyskinesia in PD.

Adipokines, Vitamin D, and Selected Inflammatory Biomarkers among Parkinson's Disease Patients with and without Dyskinesia: A Preliminary Examination

Parkinson's disease (PD), a widely recognized neurodegenerative disorder, is characterized by a spectrum of symptoms including motor fluctuations and dyskinesia. Neuroinflammation and dysregulation of adipokines are increasingly implicated in the progression of PD. This preliminary study investigated the levels of inflammatory biomarkers and adipokines, namely interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), C-reactive protein (CRP), visfatin, progranulin, and 25(OH)-vitamin D in 52 PD patients, divided equally between those with and without dyskinesia and 26 healthy controls. Significant differences in the levels of IL-6, TNF-α, visfatin, and progranulin were noted between the groups. Patients with dyskinesia exhibited notably higher IL-6 levels compared to controls, and TNF-α was significantly elevated in both PD patient groups relative to the control group. Additionally, visfatin levels were higher in PD patients without dyskinesia as opposed to those with dyskinesia, and progranulin levels were elevated in the non-dyskinetic PD group compared to controls. The findings highlight the potential role of the examined biomarkers in the pathophysiology of PD. Changes in levels of the tested inflammatory biomarkers and adipokines might be associated with Parkinson's disease and its symptoms such as dyskinesia.

Unveiled: A Case of N-Methyl-D-Aspartate Receptor Antibody Encephalitis With Delayed Diagnosis of Ovarian Teratoma

N-methyl-D-aspartate receptor (NMDAR) antibody encephalitis is an autoimmune syndrome with potentially fatal sequelae causing profound dysregulation of neurotransmission. Patients most often present with a constellation of neuropsychiatric signs and symptoms, including behavioral changes, motor disturbances, and seizures. Frequently, the development of anti-NMDAR antibodies has been linked to specific malignancies, although the exact event that triggers the production of these antibodies remains unknown. We present a case of a 25-year-old female who came into the emergency room with behavioral changes and fever. The patient had non-convulsive seizures, catatonia, and orofacial dyskinesias during the course of the admission and was treated as a case of autoimmune anti-NMDAR encephalitis. Cranial and abdominal MRI with contrast initially showed negative results, while the serum and cerebrospinal fluid studies were positive for anti-NMDAR antibodies. The patient was noted to have significant clinical improvement after being treated with high-dose intravenous steroid therapy followed by intravenous immunoglobulin (IVIg) and rituximab infusion. She was discharged stable with the resolution of neurologic symptoms four months after the diagnosis. On follow-up with her neurologist two years later, an abdominal CT scan was done and showed mature cystic teratoma. This is one of the few documented cases of anti-NMDAR encephalitis with a good response to medical treatment but had a delayed diagnosis of ovarian teratoma seen on surveillance work-up years after the diagnosis. A high index of suspicion is warranted for the diagnosis, and treatment should be started early as soon as there is clinical suspicion of the disease. Also, surveillance pelvic or abdominal imaging is important in patients who have negative initial screening but have high risks for teratomas.

ADCY5-related dyskinesia - case series with literature review

INTRODUCTION

ADCY5-related dyskinesia is a rare neurological disease caused by mutations in the gene encoding the adenylyl cyclase 5 (ADCY5) isoform, a protein that plays an important role in intracellular transmission. Variants in ADCY5 are associated with a spectrum of neurological disease encompassing dyskinesia, chorea, and dystonia. State of the-art. ADCY5 mutations result in clinically heterogeneous manifestations which comprise a range of core and less to highly variable symptoms. Due to the heterogeneous nature and difficulty in diagnosis of the disorder, available treatments are highly limited.

CLINICAL IMPLICATIONS

ADCY5-related dyskinesia was reported in 52 individuals in the literature over a five-year period (January 2017 to January 2022). We have listed all the symptoms and their frequency. The most common symptom reported in these patients was dystonia. Over 50% of patients developed dyskinesia and chorea. We report two cases of familial occurrence of symptomatic ADCY5-related dyskinesia. A 45-year-old patient presented with involuntary movements which had been occurring since childhood. The proband's neurological examination revealed dysarthria, involuntary myoclonic twitches, and choreic movements. The patient's 9-year-old son had developed involuntary movements, mainly chorea and dystonia.

FUTURE DIRECTIONS

This paper aims to summarise the recent literature on ADCY5-related neurological disorders and to present a new case of a Polish family with ADCY5 mutation. Genetic diagnostics are important in the context of possible future targeted treatments.

Dyskinesia-hyperpyrexia syndrome in Parkinson's disease triggered by overdose of levodopa - a case report and literature review

Dyskinesia-hyperpyrexia syndrome, a rare medical emergency in Parkinson's disease, is first described in 2010. It is characterized by severe continuous dyskinesia associated with rhabdomyolysis, hyperthermia and subsequent alteration of the mental state. Gradual reduction of dopaminergic dose or DBS is recommended treatment. The prognosis is usually good, but sometimes fatal. But so far, this potentially fatal complication is not widely recognized by clinicians. In emergency, if clinicians fail to make prompt diagnosis and treatment, patients' conditions may get worse, and their lives may be threatened in serious cases.

Vinpocetine improves dyskinesia in Parkinson's disease rats by reducing oxidative stress and activating the Wnt/β-catenin signaling pathway

Parkinson's disease (PD) is the commonest neurodegenerative disorder. It reduces motor and cognitive function in patients. Vinpocetine (Vinp) has the effects of anti-inflammatory and antioxidant, and could improve cognitive function in patients. This study was aimed to investigating the therapeutic effects of Vinp on dyskinesia in a 6-Hydroxydopamine hydrobromide (6-OHDA)-induced PD rat model. We constructed a PD rat model by injecting 6-OHDA, and intervened with Vinp for 7 days. The motor function of the rats was evaluated by an open-field test and rotation test. Besides, H&E staining was applied to observe the changes of dopaminergic neurons in the striatum. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in the rat striatum were detected. We assessed the impact of Vinp on α-synuclein (α-Syn) and Wnt/β-catenin signaling pathway-related molecules by western blot and qRT-PCR. Rats in the PD group showed reduced horizontal movement frequency and number of squares crossed, increased contact time and rotation frequency, and reduced number of dopaminergic neurons accompanied by severe morphological damage. Vinp treatment increased the horizontal movement frequency and number of squares crossed, reduced the contact time, and rotation frequency in PD rats. Also, Vinp downregulated α-Syn protein expression and MDA level, while upregulated SOD activity in the striatum of PD rats. Furthermore, Vinp treatment activated the Wnt/β-catenin signaling pathway in the striatum of PD rats. In conclusion, Vinp improved the dyskinesia in 6-OHDA-induced PD rats by alleviating oxidative stress, and these effects may be associated with activating the Wnt/β-catenin signaling pathway.

Striatal Serotonin 4 Receptor is Increased in Experimental Parkinsonism and Dyskinesia

Alterations of serotonin type 4 receptor levels are linked to mood disorders and cognitive deficits in several conditions. However, few studies have investigated 5-HT4R alterations in movement disorders. We wondered whether striatal 5-HT4R expression is altered in experimental parkinsonism. We used a brain bank tissue from a rat and a macaque model of Parkinson's disease (PD). We then investigated its in vivo PET imaging regulation in a cohort of macaques. Dopaminergic depletion increases striatal 5-HT4R in the two models, further augmented after dyskinesia-inducing L-Dopa. Pending confirmation in PD patients, the 5-HT4R might offer a therapeutic target for dampening PD's symptoms.

Levodopa-induced dyskinesia is preceded by increased levels of anxiety and motor impairment in Parkinson's disease patients

Introduction: Dopamine replacement therapy with levodopa is the gold standard treatment of Parkinson's disease (PD); however long-term levodopa use is associated with abnormal involuntary movements known as levodopa-induced dyskinesia (LID) in most patients. LID is not preventable and represents the major limitation of PD treatment.Objective: This study was aimed to find clinical and behavioral features that could be used to identify, years in advance, PD patients that are at high risk of developing LID in the future. Method: Data from PD patients enrolled in The Parkinson's progression markers initiative (PPMI, Michael J. Fox Foundation) that developed dyskinesia during their participation in the study were compared with those who did not, and with healthy controls.Result: LID was preceded byhigher levels of trait anxiety and increased motor impairment in PD patients. Additionally, younger age at PD diagnosis, earlier need for dopaminergic therapy and higher initial levodopa dose, were associated with future development of dyskinesia.Conclusion: These findings suggest that easily detectable clinical and behavioral alterations may help to identify PD patients that are more susceptible to develop LID.

Dopamine-Depleted Dopamine Transporter Knockout (DDD) Mice: Dyskinesia with L-DOPA and Dopamine D1 Agonists

L-DOPA is the mainstay of treatment for Parkinson's disease (PD). However, over time this drug can produce dyskinesia. A useful acute PD model for screening novel compounds for anti-parkinsonian and L-DOPA-induced dyskinesia (LID) are dopamine-depleted dopamine-transporter KO (DDD) mice. Treatment with α-methyl-para-tyrosine rapidly depletes their brain stores of DA and renders them akinetic. During sensitization in the open field (OF), their locomotion declines as vertical activities increase and upon encountering a wall they stand on one leg or tail and engage in climbing behavior termed "three-paw dyskinesia". We have hypothesized that L-DOPA induces a stereotypic activation of locomotion in DDD mice, where they are unable to alter the course of their locomotion, and upon encountering walls engage in "three-paw dyskinesia" as reflected in vertical counts or beam-breaks. The purpose of our studies was to identify a valid index of LID in DDD mice that met three criteria: (a) sensitization with repeated L-DOPA administration, (b) insensitivity to a change in the test context, and (c) stimulatory or inhibitory responses to dopamine D1 receptor agonists (5 mg/kg SKF81297; 5 and 10 mg/kg MLM55-38, a novel compound) and amantadine (45 mg/kg), respectively. Responses were compared between the OF and a circular maze (CM) that did not hinder locomotion. We found vertical counts and climbing were specific for testing in the OF, while oral stereotypies were sensitized to L-DOPA in both the OF and CM and responded to D1R agonists and amantadine. Hence, in DDD mice oral stereotypies should be used as an index of LID in screening compounds for PD.

Real-world considerations regarding the use of the combination of levodopa, carbidopa, and entacapone (Stalevo® ) in Parkinson's disease

An important aim in long-term levodopa therapy is to prolong the duration of symptomatic efficacy of each dose without increasing peak plasma concentrations above the threshold for the emergence of dyskinesias. One strategy is to enhance levodopa delivery to the brain by co-administering it with inhibitors of peripheral dopa-decarboxylase and catechol-O-methyltransferase (COMT). Levodopa, carbidopa and entacapone (LCE), available in a range of fixed-dose combinations as the branded formulation Stalevo® (Orion Pharma), has been developed to address this requirement and has been in general use for 20 years, having first been evaluated in randomized controlled trials. Experience with LCE has established that improved levodopa pharmacokinetics achieved with dual-enzyme inhibition are translated into improved clinical efficacy, including the possibility of reducing total levodopa dosage with no loss of therapeutic effect. The ease and tolerability of switching to LCE has been affirmed in the SIMCOM trial and by personal experience detailed in this review. Some 300,000 patient-years of safety data are available for LCE, including trial data for up to 5 years. Most adverse effects associated with LCE are attributable to the levodopa component rather than the enzyme inhibitors. The hepatotoxicity observed with the class comparator tolcapone has not been observed with entacapone, the COMT inhibitor in LCE, and there is no formal requirement to monitor liver function during LCE therapy. Other common side effects include diarrhoea, which is one of the more prominent non-dopaminergic adverse events, and urine discolouration, which is harmless but about which patients may require reassurance.

Neurosyphilis with oral‑facial‑lingual dyskinesia: A case report

The present study describes the case of a 52-year-old male patient who presented with subacute onset dysarthria and oral-facial-lingual dyskinesia, with normal blood glucose and acanthocyte levels, and no history of drug use. The patient tested negative for autoimmune encephalitis-related antibodies and paraneoplastic-related antibodies. The level of cerebrospinal fluid (CSF) protein was slightly elevated, and the Treponema pallidum hemagglutination assay and rapid plasma reagin test were positive in both serum and CSF samples. After 1 month of treatment with doxycycline, the patient's oral-facial-lingual dyskinesia was significantly improved, suggesting the diagnosis of neurosyphilis.

Cerebral Palsy: A Narrative Review on Childhood Disorder

Cerebral palsy, one of the most common reasons for infirmity in children and young people in developed countries, refers to several neurological diseases that impact movement and coordination. Central nervous system damage received during the first stages of brain development can cause cerebral palsy, a non-progressive condition that manifests as impairments of movement and posture. Two cases per 1000 are reported, and the causes include those mentioned for high-risk infants. Mental retardation, sensory deficiencies, failure to thrive, seizures, and behavioral or emotional issues are some of the associated difficulties. To enable interdisciplinary intervention, early identification is crucial. The result varies depending on the topography, severity, and presence of concomitant abnormalities in cerebral palsy. Cerebral palsy is caused by a static injury to the cerebral motor cortex that happens before, during, or within five years after birth. Various circumstances can influence the disease, including cerebral anoxia, cerebral hemorrhage, infection, and hereditary disorders. Interventions for children are typically provided as part of multidisciplinary rehabilitation programs. Musculoskeletal complaints are common, and pain is a significant underreported symptom.

Effectiveness and safety of safinamide in the Toledo Movement Disorders Unit

INTRODUCTION

The management of motor fluctuations in Parkinson's disease (PD) can be challenging, and current therapeutic options include the use of monoamine oxidase B inhibitors (MAO-B inhibitors), among others. The aim of this study was to evaluate the effectiveness and safety of safinamide in the clinical practice carried out in the Toledo Movement Disorders Unit.

PATIENTS AND METHODS

This is a retrospective study in which data were collected at baseline and at six months from PD patients who were started on safinamide as an add-on therapy with a stable dose of levodopa in line with standard clinical practice. An analysis was performed by subgroups: patients who were given low-dose safinamide and patients who previously received rasagiline.

RESULTS

Ninety patients (47 previously received rasagiline) completed the six-month follow-up. A statistically significant decrease in morning akinesia, nocturnal akinesia, wearing off, unpredictable off phenomenon and Unified Parkinson's Disease Rating Scale-III was observed both in those who previously received rasagiline and in those treated with low doses of safinamide. No variation was found in the dyskinesias. The adverse events described were mild, with generalised weakness, dizziness, nausea, headache and alopecia.

CONCLUSIONS

Safinamide has been shown to be effective and safe in improving motor fluctuations, motor symptoms and the subjective perception of disease severity in PD patients previously receiving rasagiline and in those receiving low-dose safinamide, all of which is accompanied by a good safety profile.

Amphiregulin blockade decreases the levodopa-induced dyskinesia in a 6-hydroxydopamine Parkinson's disease mouse model

BACKGROUND

Levodopa (L-DOPA) is considered the most reliable drug for treating Parkinson's disease (PD) clinical symptoms. Regrettably, long-term L-DOPA therapy results in the emergence of drug-induced abnormal involuntary movements (AIMs) in most PD patients. The mechanisms underlying motor fluctuations and dyskinesia induced by L-DOPA (LID) are still perplexing.

METHODS

Here, we first performed the analysis on the microarray data set (GSE55096) from the gene expression omnibus (GEO) repository and identified the differentially expressed genes (DEGs) using linear models for microarray analysis (Limma) R packages from the Bioconductor project. 12 genes (Nr4a2, Areg, Tinf2, Ptgs2, Pdlim1, Tes, Irf6, Tgfb1, Serpinb2, Lipg, Creb3l1, Lypd1) were found to be upregulated. Six genes were validated on quantitative polymerase chain reaction and subsequently, Amphiregulin (Areg) was selected (based on log2 fold change) for further experiments to unravel its involvement in LID. Areg LV_shRNA was used to knock down Areg to explore its therapeutic role in the LID model.

RESULTS

Western blotting and immunofluorescence results show that AREG is significantly expressed in the LID group relative to the control. Dyskinetic movements in LID mice were alleviated by Areg knockdown, and the protein expression of delta FOSB, the commonly attributable protein in LID, was decreased. Moreover, Areg knockdown reduced the protein expression of P-ERK. In order to ascertain whether the inhibition of the ERK pathway (a common pathway known to mediate levodopa-induced dyskinesia) could also impede Areg, the animals were injected with an ERK inhibitor (PD98059). Afterward, the AIMs, AREG, and ERK protein expression were measured relative to the control group. A group treated with ERK inhibitor had a significant decrease of AREG and phosphorylated ERK protein expression relative to the control group.

CONCLUSION

Taken together, our results indicate unequivocal involvement of Areg in levodopa-induced dyskinesia, thus a target for therapy development.