Metformin use is associated with reduced mortality risk in diabetic patients with Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) and type-2 diabetes (T2D) arguably share pathophysiologic mechanisms, resulting in a more severe phenotype and progression and diabetes is currently considered a risk factor of PD. Besides, research suggests antidiabetic therapies as potential disease-modifying strategies. The main aim was to assess the impact of a metformin-inclusive antidiabetic treatment on patient all-cause mortality. METHODS: A nested case-control prospective study including newly diagnosed PD patients reporting the onset of T2D within ±2 years from the onset of PD (n = 159) and matched (1:5; gender, year of PD onset and age at PD onset) non-diabetic cases (n = 795) followed until death or censoring. Patients on a metformin-inclusive treatment regimen were compared to those receiving other oral anti-diabetics (OADs). RESULTS: Among patients with T2D, 123 were treated with a drug regimen containing metformin (alone [65.0%] or in combination with other drugs [35.0%]) and 36 were prescribed other OADs. During a median PD duration of 96 months [IQR, 60-144], 171 patients died. Diabetes was not associated with reduced survival: fully-adjusted HR = 1.19 [95%CI, 0.81-1.76] (P = 0.37). After stratifying for T2D treatment, a metformin-inclusive regimen was not associated with increased risk of death (HR = 1.06 [95%CI, 0.61-1.84]; P = 0.83), while patients receiving other OADs had reduced survival (HR = 1.83 [95%CI, 1.01-3.32]; P = 0.034). CONCLUSIONS: Metformin use was not associated with increased risk of death in diabetic patients with PD reporting concomitant onset of the two diseases. Metformin appears to be a promising disease-modifying therapy given also the preclinical background, low cost and satisfactory safety and tolerability. Further studies are warranted to investigate its impact on disease progression.

Onset and mortality of Parkinson's disease in relation to type II diabetes.

OBJECTIVES: There is growing evidence that Parkinson's disease and diabetes are partially related diseases; however, the association between the two, and the impact of specific treatments, are still unclear. We evaluated the effect of T2D and antidiabetic treatment on age at PD onset and on all-cause mortality. RESEARCH DESIGN AND METHODS: The standardized rate of T2D was calculated for PD patients using the direct method and compared with subjects with essential tremor (ET) and the general Italian population. Age at onset and survival were also compared between patients without T2D (PD-noT2D), patients who developed T2D before PD onset (PD-preT2D) and patients who developed T2D after PD onset (PD-postT2D). RESULTS: We designed a retrospective and prospective study. The T2D standardized ratio of PD (N = 8380) and ET (N = 1032) patients was 3.8% and 6.1%, respectively, while in the Italian general population, the overall prevalence was 5.3%. In PD-preT2D patients, on antidiabetic treatment, the onset of PD was associated with a + 6.2 year delay (p < 0.001) while no difference was observed in PD-postT2D. Occurrence of T2D before PD onset negatively affected prognosis (adjusted hazard ratio = 1.64 [95% CI 1.33-2.02]; p < 0.001), while no effect on survival was found in PD-postT2D subjects (hazard ratio = 0.86, [95% CI 0.53-1.39]; p = 0.54). CONCLUSIONS: T2D, treated with any antidiabetic therapy before PD, is associated with a delay in its onset. Duration of diabetes increases mortality in PD-preT2D, but not in PD-postT2D. These findings prompt further studies on antidiabetic drugs as a potential disease-modifying therapy for PD.

Gut Microbiota in Monozygotic Twins Discordant for Parkinson's Disease.

Differences in gut microbiota between Parkinson's disease patients and controls seem to depend on multiple-frequently unmeasured-confounders. Monozygotic twins offer a unique model for controlling several factors responsible for interpersonal variation in gut microbiota. Fecal samples from 20 monozygotic twin pairs (n = 40) discordant for Parkinson's disease were studied (metagenomic shotgun analysis). Paired data analysis detected minimal differences in bacterial taxa abundance at species level (Bacteroides pectinophilus [p = 0.037], Bifidobacterium pseudocatenulatum [p = 0.050], and Bifidobacterium catenulatum [p = 0.025]) and in predicted metabolic pathways (primary bile acid biosynthesis [p = 0.037]). Additional studies are warranted to understand the role of gut microbiota in the pathogenesis of Parkinson's disease. ANN NEUROL 2022;92:631-636.

Long-term safety, discontinuation and mortality in an Italian cohort with advanced Parkinson's disease on levodopa/carbidopa intestinal gel infusion.

INTRODUCTION: Levodopa/carbidopa intestinal gel (LCIG) is an effective treatment in patients with advanced Parkinson's disease (PD) with consolidated evidence of clinical efficacy. However, only few studies have assessed long-term safety, causes of discontinuation, mortality, and relative predictors. METHODS: We conducted a retrospective analysis of 79 PD patients treated with LCIG between 2005 and 2020 in two Italian Neurological Centers, recording all adverse events (AEs), including weight loss (WL). Kaplan-Meier curve was used to estimate the time to discontinuation and survival. Cox proportional hazard model was employed to identify predictors of discontinuation and mortality, while Pearson's correlation was used to analyze predictors of WL. RESULTS: The average follow-up was 47.7 ± 40.5 months and the median survival from disease onset was 25 years. There were three cases of polyradiculoneuropathy Guillain-Barre syndrome-like, all occurred in the early years of LCIG treatment. Twenty-five patients died (32%), 18 on LCIG (including one suicide) and seven after discontinuation. The mean WL was 3.62 ± 7.5 kg, which correlated with levodopa dose at baseline (p = 0.002), levodopa equivalent daily dose (LEDD) baseline (p = 0.017) and off-duration (p = 0.0014), but not dyskinesia. Peristomal complications emerged as a negative predictor of discontinuation (p = 0.008). CONCLUSIONS: LCIG has a relatively satisfactory long-term safety profile and efficacy and a relatively low rate of discontinuation. Peristomal complications may represent a predictor of longer duration of therapy. According to the mortality analysis, LCIG patients show a long lifespan. Delaying the initiation of LCIG does not affect the sustainability of LCIG therapy.

Vitamin D Status and Parkinson's Disease.

Parkinson's disease (PD) is a complex and progressive neurodegenerative disease, characterized by resting tremor, rigidity, slowness of movement, and postural instability. Furthermore, PD is associated with a wide spectrum of non-motor symptoms that add to overall disability. In recent years, some investigations, from basic science to clinical applications, have focused on the role of vitamin D in PD, often with controversial findings. Vitamin D has widespread effects on several biological processes in the central nervous system, including neurotransmission in dopaminergic neural circuits. Various studies have recorded lower levels of vitamin D in PD patients than in healthy controls. Low vitamin D status has also been correlated with the risk for PD and motor severity, whereas less is known about the effects vitamin D has on cognitive function and other non-motor symptoms. This review aims to better characterize the correlation between vitamin D and PD, clarify the role of vitamin D in PD prevention and treatment, and discuss avenues for future research in this field.

Design and Operation of the Lombardy Parkinson's Disease Network.

Background: Parkinson's disease (PD) is one of the most common chronic neurological conditions leading to disability and social burden. According to the 2016 Italian National Plan on Chronic Diseases, regional health authorities are implementing dedicated networks to manage neurological diseases, including PD. Methods: A panel of experts representing health-care providers in Lombardy reached consensus on the organization of a patient-centered regional PD healthcare network. Results: The panel proposed a structure and organization implementing a hub-and-spoke PD network model. Three levels of neurological services were identified: General Neurologist, PD Clinic, PD Center. This model was applied to health service providers currently accredited in Lombardy, yielding 12 candidate PD Centers, each serving an area of ~1,000-2,000 km2, and not less than 27 PD Clinics. The panel agreed on uniform diagnostic and staging criteria for PD, and on a minimum common clinical data set, on PD patient management by the network at initial and follow-up assessments, on the cadence of follow-up visits, on patient referrals, and on outcome measures for the assessment of network activities. Conclusions: The implementation of disease-centered networks for chronic neurological diseases provides an innovative opportunity to improve patient management, facilitate research and education.

Case Report: Efficacy of Rituximab in a Patient With Familial Mediterranean Fever and Multiple Sclerosis.

Familial Mediterranean Fever (FMF) is a genetic autoinflammatory disease characterized by recurrent episodes of fever and serositis caused by mutations in the MEFV gene, while Multiple Sclerosis (MS) is an inflammatory demyelinating disease of the CNS with genetic and environmental etiology. The two diseases rarely occur in association with relevant implications for clinical management and drug choice. In this paper, we present the case of a 53-year-old male with an autosomal dominant FMF since childhood who presented acute paresthesia at the right part of the body. He performed a brain and spinal cord MRI, which showed multiple brain lesions and a gd-enhancing lesion in the cervical spinal cord, and then received a diagnosis of MS. He then started Interferonß-1a which was effective but not tolerated and caused hepatotoxicity, and then shifted to Rituximab with 3-month clinical and neuroradiological efficacy.

Deep brain stimulation for dystonia due to cerebral palsy: A review.

Cerebral palsy (CP) is a heterogeneous group of syndromes that cause a non-progressive disorder of early onset, with abnormal control of movement and posture. Various aetiologies can cause the CP clinical spectrum, but all have a disruption of motor control in common. CP can be divided into four major types based on the motor disability: predominant spastic, dyskinetic, ataxic and mixed form. Dyskinetic CP (DCP) is the most common cause of acquired dystonia in children. The treatment of DCP is challenging because most individuals have mixed degrees of chorea, athetosis and dystonia. Pharmacological treatment is often unsatisfactory. Functional neurosurgery, in particular deep brain stimulation targeting the basal ganglia or the cerebellum, is emerging as a promising therapeutic approach in selected patients with DCP. We evaluated herein the effects of DBS on patients with DCP in a review of published patient data in the largest available studies.

Therapeutic advances in dystonia.

Knowledge on dystonia has greatly improved recently, because of a renewed effort in understanding its cause, pathophysiology, and clinical characterization. Different drug classes traditionally have been used for the symptomatic treatment of dystonia, more recently surpassed by the introduction of botulinum neurotoxins and deep brain stimulation. No curative or disease-modifying treatments are available. Recent knowledge regarding the pathophysiology of inherited dystonias is highlighting new potential treatment strategies. We review therapeutic advances in dystonia that have been published over the last 3 years, particularly regarding oral medications, local injections of botulinum neurotoxins, deep brain stimulation, and transcranial or epidural brain stimulations. We discuss evidence of efficacy, highlight recent advances, and focus on key areas under development.

Causes of withdrawal of duodenal levodopa infusion in advanced Parkinson disease.

OBJECTIVE: We performed a real-life observation of patients with Parkinson disease (PD) who received duodenal levodopa infusion (DLI) to determine which adverse events caused treatment discontinuation and when such events occurred. METHODS: All consecutive patients with PD treated at the Carlo Besta Neurological Institute were included. The patients were evaluated at baseline and after DLI at regular intervals. Their motor condition was assessed and adverse events were recorded. RESULTS: Thirty-five patients with PD (15 men and 20 women) were included. They received DLI implants between October 2007 and September 2013. Four patients died of causes unrelated to the procedure. At the end of the study, 21 patients (60%) were still on treatment. DLI provided efficacious motor control in all patients. Discontinuation was most frequently caused by device- or infusion-related adverse events. Ten patients of the remaining 31 discontinued DLI. There were 2 main causes of withdrawal: stoma infection (4 patients), and worsening of dyskinesias not manageable with infusion reduction (3 patients). In most patients, discontinuations occurred during the first year after implant. Risk of discontinuation was related to age at implant, but no other demographic or clinical variables. CONCLUSIONS: We identified 2 main causes leading to DLI withdrawal during the first year postimplant and suggest adopting measures to prevent such occurrences. Elderly patients are at higher risk of treatment discontinuation.

EuroInf: a multicenter comparative observational study of apomorphine and levodopa infusion in Parkinson's disease.

Subcutaneous apomorphine infusion (Apo) and intrajejunal levodopa infusion (IJLI) are two treatment options for patients with advanced Parkinson's disease (PD) and refractory motor complications, with varying cost of treatment. There are no multicenter studies comparing the effects of the two strategies. This open-label, prospective, observational, 6-month, multicenter study compared 43 patients on Apo (48.8% males, age 62.3 ± 10.6 years; disease duration: 14 ± 4.4 years; median H & Y stage 3; interquartile range [IQR]: 3-4) and 44 on IJLI (56.8% males, age 62.7 ± 9.1 years; disease duration: 16.1 ± 6.7 years; median H & Y stage 4; IQR, 3-4). Cohen's effect sizes (≥0.8 considered as large) were "large" with both therapies with respect to total motor, nonmotor, and quality-of-life scores. The Non-Motor Symptoms Scale (NMSS) with Apo showed moderate improvement, whereas sleep/fatigue, gastrointestinal, urinary, and sexual dimensions of the NMSS showed significantly higher improvement with IJLI. Seventy-five percent on IJLI improved in their quality-of-life and nonmotor symptoms (NMS), whereas in the Apo group, a similar proportion improved in quality of life, but 40% in NMS. Adverse effects included peritonitis with IJLI and skin nodules on Apo. Based on this open-label, nonrandomized, comparative study, we report that, in advanced Parkinson's patients, both IJLI and Apo infusion therapy appear to provide a robust improvement in motor symptoms, motor complications, quality-of-life, and some NMS. Controlled, randomized studies are required.

Effects of rotigotine on Parkinson's disease-related sleep disturbances.

INTRODUCTION: Sleep abnormalities are a frequent non-motor symptom and a prominent cause of disability in patients with Parkinson's disease (PD). AREAS COVERED: This review discusses what is currently known about the characteristics of sleep disturbances in PD patients and attempts to clarify the role of dopaminergic pathways in their pathogenesis as well as the beneficial effect of dopaminergic agents in their treatment. In particular, this review will focus on the effects of transdermal rotigotine on improving PD-related sleep disorders. EXPERT OPINION: Sleep disturbances are common in PD, and these disturbances can be reduced or resolved, in large part, by preventing or attenuating nocturnal and early morning motor and non-motor symptoms of PD. The studies discussed within this review suggest that sleep disorders are not just a consequence of motor impairment and dopaminergic therapy but are an integral part of the neurodegenerative process of PD. This is supported by the appearance of specific sleep disturbances, which are related to degeneration of the brainstem areas involved in the regulation of sleep/wake states in advance of typical PD symptoms. Development of more detailed diagnostic tools aimed at detecting sleep disturbances and at defining the main causative factors of sleep disturbances in PD will lead to improved treatment of these disturbances.

Pulsatile or continuous dopaminomimetic strategies in Parkinson's disease.

Levodopa is the most effective treatment for Parkinson's disease (PD) for both motor and non-motor control. Pulsatile levodopa administration likely contributes to the development of motor fluctuations and dyskinesia after a few years. All studies comparing levodopa versus dopamine agonist early therapy indicate that initiation with agonists is associated with a reduced risk of motor complications - in particular, dyskinesias - possibly because agonists' longer half-lives provide continuous dopaminergic delivery. Indeed, this therapeutic strategy may delay the emergence of motor fluctuations and dyskinesia which is essential to maintaining satisfactory quality of life. In advanced disease various levodopa-based strategies may be tried to control motor complications, such as dose fragmentation (smaller, more frequent dosing) or the use of orally administered, liquid levodopa formulations that may reduce off-time intervals or facilitate absorption. More recently introduced, continuous levodopa delivery by duodenal infusion (but also apomorphine infusion) may represent a more effective approach to treat motor complications in advanced PD, and its effect can be perceived by improvement both in clinical scales as well as in health-related items. Infusion therapies may reverse motor complications in complicated patients with significant benefit on quality of life.

Pharmacokinetic evaluation of pramipexole.

INTRODUCTION: Immediate-release (IR) pramipexole dihydrochloride is indicated for the treatment of signs and symptoms of idiopathic Parkinson's disease (PD). It is administered alone (without levodopa) or in combination with levodopa, during the entire progress of the disease, up to an advanced stage. Currently, it is also indicated for the treatment of moderate-to-severe primary restless legs syndrome (RLS). An extended-release (ER) formulation of pramipexole has been developed to allow a once-daily administration and to provide more stable dopaminergic stimulation in PD patients. AREAS COVERED: This review summarizes the overall pharmacokinetic profile of pramipexole for both the IR and ER formulations. Also discussed are the clinically relevant determinants of pramipexole peripheral pharmacokinetics and the potential role of genetic and clinical determinants in drug efficacy. EXPERT OPINION: Pramipexole is a non-ergot agonist with selective affinity for dopamine receptors of the D2 subfamily, in particular D3. Pramipexole has a very low affinity for serotoninergic 5-HT2A and 5-HT2B receptors, as well as D1-type receptors. Furthermore, it does not carry the risk to induce valvular heart disease or pulmonary and retroperitoneal fibrosis, seen with long-term use of the ergot-derived dopamine agonists. The recent introduction of a once-daily formulation poses significant advantages for patients, reflected by relatively stable plasma levels. The most obvious benefit is convenience of use and better adherence to treatment schedule. Additional advantages could include the opportunity to provide more continuous drug delivery in a fashion that could help minimize dyskinesia risk, if the drug is used early in the disease course.

Once-daily pramipexole for the treatment of early and advanced idiopathic Parkinson's disease: implications for patients.

Immediate-release (IR) pramipexole is indicated for the symptomatic treatment of idiopathic Parkinson's disease (PD), either alone (without levodopa) or in combination with levodopa, that is, during the entire progress of disease up to the advanced stage. It is also currently indicated for the treatment of moderate-to-severe primary restless legs syndrome (RLS). An extended-release (ER) formulation of pramipexole has been developed to allow a once-daily formulation and to provide more stable dopaminergic stimulation. This review summarized the pharmacokinetic profile of pramipexole for both the IR and ER formulations, and discussed the role of pramipexole in the management of early and advanced PD. The introduction of a once-daily formulation of pramipexole poses significant potential advantages for patients and this is reflected by relatively stable plasma levels. The most obvious benefit is convenience of use and better adherence to treatment schedule. Additional advantages may be represented by the opportunity to provide continuous drug delivery in a fashion that could potentially help minimize dyskinesia risk if the drug is used early in the disease course.

Pathological gambling in Parkinson's disease: disease related or drug related?

Pathological gambling and other impulse-control disorders occur in susceptible Parkinson's disease patients during dopaminergic therapy, particularly in association with dopamine agonists. Additional factors such as age at onset play an important role, and predisposing personality traits have been identified both in treated patients, as well as in patients even before therapy is initiated. The contributions of specific allelic polymorphisms of the dopamine receptor and transporter genes were also tested as predictors of adverse effects of dopaminergic therapy but results are not conclusive. Recent imaging studies have shed light on the mechanism underlying pathological gambling. Resting-state brain perfusion of Parkinson's disease gamblers showed higher activity in 'limbic' areas associated with addictive processes. More importantly, severity of this behavior is associated with the impaired functioning of brain regions that are involved in 'top-down' cognitive monitoring and inhibition of inappropriate behaviors. This evidence is consistent with a significant contribution of disease-related factors.