Body weight in patients with Parkinson's disease

Neuroinflammation and Dyskinesia: A Possible Causative Relationship?

Levodopa (L-DOPA) treatment represents the gold standard therapy for Parkinson's disease (PD) patients. L-DOPA therapy shows many side effects, among them, L-DOPA-induced dyskinesias (LIDs) remain the most problematic. Several are the mechanisms underlying these processes: abnormal corticostriatal neurotransmission, pre- and post-synaptic neuronal events, changes in gene expression, and altered plasticity. In recent years, researchers have also suggested non-neuronal mechanisms as a possible cause for LIDs. We reviewed recent clinical and pre-clinical studies on neuroinflammation contribution to LIDs. Microglia and astrocytes seem to play a strategic role in LIDs phenomenon. In particular, their inflammatory response affects neuron-glia communication, synaptic activity and neuroplasticity, contributing to LIDs development. Finally, we describe possible new therapeutic interventions for dyskinesia prevention targeting glia cells.

Using artificial intelligence to identify drugs for repurposing to treat l-DOPA-induced dyskinesia

Repurposing regulatory agency-approved molecules, with proven safety in humans, is an attractive option for developing new treatments for disease. We identified and assessed the efficacy of 3 drugs predicted by an in silico screen as having the potential to treat l-DOPA-induced dyskinesia (LID) in Parkinson's disease. We analysed ∼1.3 million Medline abstracts using natural language processing and ranked 3539 existing drugs based on predicted ability to reduce LID. 3 drugs from the top 5% of the 3539 candidates; lorcaserin, acamprosate and ganaxolone, were prioritized for preclinical testing based on i) having a novel mechanism of action, ii) having not been previously validated for the treatment of LID, iii) being blood-brain-barrier penetrant and orally bioavailable and iv) being clinical trial ready. We assessed the efficacy of acamprosate, ganaxolone and lorcaserin in a rodent model of l-DOPA-induced hyperactivity, with lorcaserin affording a 58% reduction in rotational asymmetry (P < 0.05) compared to vehicle. Acamprosate and ganaxolone failed to demonstrate efficacy. Lorcaserin, a 5HT2C agonist, was then further tested in MPTP lesioned dyskinetic macaques where it afforded an 82% reduction in LID (P < 0.05), unfortunately accompanied by a significant increase in parkinsonian disability. In conclusion, although our data do not support the repurposing of lorcaserin, acamprosate or ganaxolone per se for LID, we demonstrate value of an in silico approach to identify candidate molecules which, in combination with an in vivo screen, can facilitate clinical development decisions. The present study adds to a growing literature in support of this paradigm shifting approach in the repurposing pipeline.

The olfactory bulb: A neuroendocrine spotlight on feeding and metabolism

Olfaction is the most ancient sense and is needed for food-seeking, danger protection, mating and survival. It is often the first sensory modality to perceive changes in the external environment, before sight, taste or sound. Odour molecules activate olfactory sensory neurons that reside on the olfactory epithelium in the nasal cavity, which transmits this odour-specific information to the olfactory bulb (OB), where it is relayed to higher brain regions involved in olfactory perception and behaviour. Besides odour processing, recent studies suggest that the OB extends its function into the regulation of food intake and energy balance. Furthermore, numerous hormone receptors associated with appetite and metabolism are expressed within the OB, suggesting a neuroendocrine role outside the hypothalamus. Olfactory cues are important to promote food preparatory behaviours and consumption, such as enhancing appetite and salivation. In addition, altered metabolism or energy state (fasting, satiety and overnutrition) can change olfactory processing and perception. Similarly, various animal models and human pathologies indicate a strong link between olfactory impairment and metabolic dysfunction. Therefore, understanding the nature of this reciprocal relationship is critical to understand how olfactory or metabolic disorders arise. This present review elaborates on the connection between olfaction, feeding behaviour and metabolism and will shed light on the neuroendocrine role of the OB as an interface between the external and internal environments. Elucidating the specific mechanisms by which olfactory signals are integrated and translated into metabolic responses holds promise for the development of targeted therapeutic strategies and interventions aimed at modulating appetite and promoting metabolic health.

Weight loss in Parkinson's disease: A retrospective comparison between oral medication and device-assisted therapies

OBJECTIVE

Weight loss (WL) is the most common symptom among patients with Parkinson's disease (PD) and has been reported to start several years before the diagnosis of PD. The relationship between WL and PD treatment is complex. This study aimed to characterize the impact of PD treatment on WL and find clues to establish the administration of nutrition for patients with PD.

MATERIALS AND METHODS

Eighty-two patients with PD (mean age, 58.4 ± 10.2 years; mean Hoehn and Yahr stage, 3.2 ± 0.7) were recruited. Their treatments included deep brain stimulation (DBS) therapy (n = 34), levodopa/carbidopa intestinal gel (LCIG) therapy (n = 13), and oral medication alone (n = 35). Based on the medical records, the age of onset, disease duration, treatment options, videofluoroscopic dysphagia scale, blood test results, and weight change were collected.

RESULTS

The median WL per year and rate of WL were -1.0 ± 2.8 kg and -1.9 ± 4.7 %, respectively. Most patients (93 %) were classified into normal nutrition and mild malnutrition groups by their CONUT scores. The median WL of the DBS group was significantly lower than that of the oral medication alone group (p < 0.01). The rate of WL showed a significant negative correlation with the age of onset (rho = -0.328, p = 0.003), but showed a significant positive correlation with the disease duration (rho = 0.231, p = 0.04).

CONCLUSION

These results highlighted WL in the early stages of PD and suggested the need for adequate monitoring for patients undergoing device-aided therapy as well as oral medicine-treated patients with greater WL.

Impaired skeletal muscle health in Parkinsonian syndromes: clinical implications, mechanisms and potential treatments

There is increasing evidence that neurodegenerative disorders including the Parkinsonian syndromes are associated with impaired skeletal muscle health, manifesting as wasting and weakness. Many of the movement problems, lack of muscle strength and reduction in quality of life that are characteristic of these syndromes can be attributed to impairments in skeletal muscle health, but this concept has been grossly understudied and represents an important area of unmet clinical need. This review describes the changes in skeletal muscle health in idiopathic Parkinson's disease and in two atypical Parkinsonian syndromes, the most aggressive synucleinopathy multiple system atrophy, and the tauopathy progressive supranuclear palsy. The pathogenesis of the skeletal muscle changes is described, including the contribution of impairments to the central and peripheral nervous system and intrinsic alterations. Pharmacological interventions targeting the underlying molecular mechanisms with therapeutic potential to improve skeletal muscle health in affected patients are also discussed. Although little is known about the mechanisms underlying these conditions, current evidence implicates multiple pathways and processes, highlighting the likely need for combination therapies to protect muscle health and emphasizing the merit of personalized interventions for patients with different physical capacities at different stages of their disease. As muscle fatigue is often experienced by patients prior to diagnosis, the identification and measurement of this symptom and related biomarkers to identify early signs of disease require careful interrogation, especially for multiple system atrophy and progressive supranuclear palsy where diagnosis is often made several years after onset of symptoms and only confirmed post-mortem. We propose a multidisciplinary approach for early diagnosis and implementation of personalized interventions to preserve muscle health and improve quality of life for patients with typical and atypical Parkinsonian syndromes.

Weight and survival after deep brain stimulation for Parkinson's disease

BACKGROUND

Weight loss in Parkinson's disease (PD) is common and associated with increased mortality. The clinical significance of weight changes following deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus internus (GPi) is unclear.

OBJECTIVES

To address (1) whether PD patients exhibit progressive weight loss, (2) whether staged DBS surgery is associated with weight changes, and (3) whether survival after DBS correlates with post-DBS weight.

METHODS

This is a single-center, longitudinal, retrospective cohort study of 1625 PD patients. We examined trends in weight over time and the relationship between weight and years survival after DBS using regression and mixed model analyses.

RESULTS

There was a decline in body weight predating motor symptom onset (n = 756, 0.70 ± 0.03% decrease per year, p < 0.001). Weight decline accelerated in the decade preceding death (n = 456, 2.18 ± 0.31% decrease per year, p < 0.001). DBS patients showed a weight increase of 2.0 ± 0.33% at 1 year following the first DBS lead implant (n = 455) and 2.68 ± 1.1% at 3 years if a contralateral DBS lead was placed (n = 249). The bilateral STN DBS group gained the most weight after surgery during 6 years of follow up (vs bilateral GPi, 3.03 ± 0.45% vs 1.89 ± 0.31%, p < 0.01). An analysis of the DBS cohort with date of death available (n = 72) revealed that post-DBS weight (0-12 months after the first or 0-36 months after the second surgery) was positively associated with survival (R2 = 0.14, p < 0.001).

DISCUSSION

Though PD is associated with significant weight loss, DBS patients gained weight following surgery. Higher post-operative weight was associated with increased survival. These results should be replicated in other cohorts.

Changes in the Secretion of Melatonin and Selected Adipokines during the Progression of Parkinson's Disease-Preliminary Studies

Parkinson's disease (PD) is one of the most common neurodegenerative diseases affecting elderly people. Considering the gap in the literature on melatonin and adipokine levels in PD patients at various stages of the disease, we conducted a study to investigate the levels of selected parameters in PD patients at the disease's early (ES) and advanced (AS) stages. Melatonin, leptin, adiponectin, and resistin concentrations were measured in the blood serum of 20 PD patients without dyskinesia (ES), 24 PD patients with dyskinesia (AS), and 20 healthy volunteers as a control group (CG). The data were analyzed using ANOVA. Melatonin was significantly lower in ES (p < 0.05) and higher in AS patients (p < 0.05) compared to CG. The level of leptin was increased both in ES (p < 0.001) and AS (p < 0.001) versus CG, while resistin was increased only in patients with dyskinesia (p < 0.05). Higher melatonin (p < 0.001) and resistin (p < 0.05) and lower leptin (p < 0.05) levels were found in AS versus ES. The main findings of the study include the changes in inflammatory markers' levels during PD and a surprising increase in melatonin level in dyskinesia patients. Further research is necessary, which will be aimed at modulating the secretion of melatonin and adipokines as a treatment target for PD.

Orexin pathway in Parkinson's disease: a review

Parkinson's disease (PD) is a progressive neurodegenerative disease (NDD) caused by dopaminergic neuron degeneration in the substantia nigra (SN). Orexin is a neuropeptide that plays a role in the pathogenesis of PD. Orexin has neuroprotective properties in dopaminergic neurons. In PD neuropathology, there is also degeneration of orexinergic neurons in the hypothalamus, in addition to dopaminergic neurons. However, the loss of orexinergic neurons in PD began after the degeneration of dopaminergic neurons. Reduced activity of orexinergic neurons has been linked to developing and progressing motor and non-motor symptoms in PD. In addition, the dysregulation of the orexin pathway is linked to the development of sleep disorders. The hypothalamic orexin pathway regulates various aspects of PD neuropathology at the cellular, subcellular, and molecular levels. Finally, non-motor symptoms, particularly insomnia and disturbed sleep, promote neuroinflammation and the accumulation of neurotoxic proteins as a result of defects in autophagy, endoplasmic reticulum (ER) stress, and the glymphatic system. As a result, this review aimed to highlight the potential role of orexin in PD neuropathology.

Sex-dependent metal accumulation and immunoexpression of Hsp70 and Nrf2 in rats' brain following manganese exposure

Manganese (Mn), although important for multiple cellular processes, has posed environmental health concerns due to its neurotoxic effects. In recent years, there have been extensive studies on the mechanism of Mn-induced neuropathology, as well as the sex-dependent vulnerability to its neurotoxic effects. Nonetheless, cellular mechanisms influenced by sex differences in susceptibility to Mn have yet to be adequately characterized. Since oxidative stress is a key mechanism of Mn neurotoxicity, here, we have probed Hsp70 and Nrf2 proteins to investigate the sex-dependent changes following exposure to Mn. Male and female rats were administered intraperitoneal injections of MnCl2 (10 mg/kg and 25 mg/kg) 48 hourly for a total of eight injections (15 days). We evaluated changes in body weight, as well as Mn accumulation, Nrf2 and Hsp70 expression across four brain regions; striatum, cortex, hippocampus and cerebellum in both sexes. Our results showed sex-specific changes in body-weight, specifically in males but not in females. Additionally, we noted sex-dependent accumulation of Mn in the brain, as well as in expression levels of Nrf2 and Hsp70 proteins. These findings revealed sex-dependent susceptibility to Mn-induced neurotoxicity corresponding to differential Mn accumulation, and expression of Hsp70 and Nrf2 across several brain regions.

The Deficiency of SCARB2/LIMP-2 Impairs Metabolism via Disrupted mTORC1-Dependent Mitochondrial OXPHOS

Deficiency in scavenger receptor class B, member 2 (SCARB2) is related to both Gaucher disease (GD) and Parkinson’s disease (PD), which are both neurodegenerative-related diseases without cure. Although both diseases lead to weight loss, which affects the quality of life and the progress of diseases, the underlying molecular mechanism is still unclear. In this study, we found that Scarb2^−/− mice showed significantly reduced lipid storage in white fat tissues (WAT) compared to WT mice on a regular chow diet. However, the phenotype is independent of heat production, activity, food intake or energy absorption. Furthermore, adipocyte differentiation and cholesterol homeostasis were unaffected. We found that the impaired lipid accumulation of Adiponectin-cre; Scarb2^fl/fl mice was due to the imbalance between glycolysis and oxidative phosphorylation (OXPHOS). Mechanistically, the mechanistic target of rapamycin complex 1 (mTORC1)/ eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1) pathway was down-regulated in Scarb2 deficient adipocytes, leading to impaired mitochondrial respiration and enhanced glycolysis. Altogether, we reveal the role of SCARB2 in metabolism regulation besides the nervous system, which provides a theoretical basis for weight loss treatment of patients with neurodegenerative diseases.

Umami and Other Taste Perceptions in Patients With Parkinson's Disease

Objective

Studies of taste perceptions in Parkinson’s disease (PD) patients have been controversial, and none of these studies have assessed umami taste. This study aimed to assess umami, along with the other 4 taste functions in PD patients.

Methods

Participants were tested for gustation using the modified filter paper disc method and olfaction using the modified Sniffin’ Stick-16 (mSS-16) test (only 14 culturally suitable items were used). A questionnaire evaluated patients’ subjective olfactory and gustatory dysfunction, taste preference, appetite, and food habits.

Results

A total of 105 PD patients and 101 age- and sex-matched controls were included. The body mass index (BMI) of PD patients was lower than that of controls (PD = 22.62, controls = 23.86, p = 0.028). The mSS-16 score was 10.7 for controls and 6.4 for PD patients (p < 0.001) (normal ≥ 9). Taste recognition thresholds (RTs) for sweet, salty, sour, bitter and umami tastes were significantly higher in PD, indicating poorer gustation. All taste RTs correlated with each other, except for umami. Most patients were unaware of their dysfunction. Patients preferred sweet, salty and umami tastes more than the controls. Dysgeusia of different tastes in patients was differentially associated with poorer discrimination of tastes, an inability to identify the dish and adding extra seasoning to food. BMI and mSS-16 scores showed no correlation in either patients or controls.

Conclusion

PD patients have dysgeusia for all five tastes, including umami, which affects their appetite and diet. Patients preferred sweet, salty and umami tastes. This information can help adjust patients’ diets to improve their nutritional status.

Sweets for my sweet: modulation of the limbic system drives salience for sweet foods after deep brain stimulation in Parkinson's disease

BACKGROUND

An increase in body weight is observed in the majority of patients with Parkinson's disease (PD) who undergo deep brain stimulation (DBS) of the subthalamic nucleus (STN) although the mechanisms are unclear.

OBJECTIVES

To identify the stimulation-dependent effects on reward-associated and attention-associated neural networks and to determine whether these alterations in functional connectivity are associated with the local impact of DBS on different STN parcellations.

METHODS

We acquired functional task-related MRI data from 21 patients with PD during active and inactive STN DBS and 19 controls while performing a food viewing paradigm. Electrode placement in the STN was localised using a state-of-the-art approach. Based on the 3D model, the local impact of STN DBS was estimated.

RESULTS

STN DBS resulted in a mean improvement of motor function of 22.6%±15.5% (on medication) and an increase of body weight of ~4 kg within 2 years of stimulation. DBS of the limbic proportion of the STN was associated with body weight gain and an increased functional connectivity within the salience network and at the same time with a decreased activity within the reward-related network in the context of sweet food images.

CONCLUSIONS

Our findings indicate increased selective attention for high-caloric foods and a sweet food seeking-like behaviour after DBS particularly when the limbic proportion of the STN was stimulated.

The Interactions between Adipose Tissue Secretions and Parkinson's disease; The Role of Leptin

Leptin is a hormone that regulates appetite by acting on receptors in the hypothalamus, where it modifies food intake to maintain equilibrium with the body energy resources. Leptin and its receptors are widely distributed in the central nervous system, suggesting that they may give neuronal survival signals. The potential of leptin to decrease/increase neuronal damage and neuronal plasticity in Parkinson's diseases (PD) is the subject of this review, which outlines our current knowledge of how leptin acts in the brain. Although leptin-mediated neuroprotective signaling results in neuronal death prevention, it can affect neuroinflammatory cascades and also neuronal plasticity which contribute to PD pathology. Other neuroprotective molecules, such as insulin and erythropoietin, share leptin-related signaling cascades, and therefore constitute a component of the neurotrophic effects mediated by endogenous hormones. With the evidence that leptin dysregulation causes increased neuronal vulnerability to damage in PD, using leptin as a target for therapeutic modification is an appealing and realistic option.

Role of Oxytocin in Different Neuropsychiatric, Neurodegenerative, and Neurodevelopmental Disorders

Oxytocin has recently gained significant attention because of its role in the pathophysiology and management of dominant neuropsychiatric disorders. Oxytocin, a peptide hormone synthesized in the hypothalamus, is released into different brain regions, acting as a neurotransmitter. Receptors for oxytocin are present in many areas of the brain, including the hypothalamus, amygdala, and nucleus accumbens, which have been involved in the pathophysiology of depression, anxiety, schizophrenia, autism, Alzheimer's disease, Parkinson's disease, and attention deficit hyperactivity disorder. Animal studies have spotlighted the role of oxytocin in social, behavioral, pair bonding, and mother-infant bonding. Furthermore, oxytocin protects fetal neurons against injury during childbirth and affects various behaviors, assuming its possible neuroprotective characteristics. In this review, we discuss some of the concepts and mechanisms related to the role of oxytocin in the pathophysiology and management of some neuropsychiatric, neurodegenerative, and neurodevelopmental disorders.

Prevention and Treatment of Hardware-Related Infections in Deep Brain Stimulation Surgeries: A Retrospective and Historical Controlled Study

Background

Hardware-related infection in deep brain stimulation (DBS) is one of the most commonly reported complications frequently resulting in the removal of implantable pulse generator (IPG).

Objective

The aim of this study was to establish a useful strategy to better prevent and treat those infections and to improve the preservation rates of IPG.

Methods

We conducted a retrospective and historical controlled study of all adult patients (≥18 years old) who had undergone initial DBS implantation at a single center. All participants were enrolled in the control group (between June 2005 and June 2014) or intervention group (between July 2014 and May 2019) based on their surgery dates. We used the intraoperative irrigation with hydrogen dioxide solution in the intervention group. Based on the dates of diagnosis, patients with hardware-related infection after DBS were enrolled in group A (between June 2005 and June 2014) or group B (between July 2014 and May 2019). IPG-sparing algorithm (Isa) was applied for group B. The early-onset IPG infections of the control and intervention groups were evaluated. The IPG preservation rates in both groups A and B were statistically analyzed.

Results

Six cases of early IPG infection and subsequent IPG removal occurred in the control group, while none occurred after intraoperative usage of the hydrogen dioxide in the intervention group. IPG preservation rate of infected cases in group B was significantly higher than that in group A (70% vs.16%, p = 0.004).

Conclusion

The combined application of hydrogen dioxide solution and Isa seems to be an effective strategy to prevent IPG infection.

The Thermodynamic Consequences of Parkinson's Disease

Several lines of evidence point to a pervasive disturbance of energy balance in Parkinson's disease (PD). Weight loss, common and multifactorial, is the most observable sign of this. Bradykinesia may be best understood as an underinvestment of energy in voluntary movement. This accords with rodent experiments that emphasise the importance of dopamine in allocating motor energy expenditure. Oxygen consumption studies in PD suggest that, when activities are standardised for work performed, these inappropriate energy thrift settings are actually wasteful. That the dopaminergic deficit of PD creates a problem with energy efficiency highlights the role played by the basal ganglia, and by dopamine, in thermodynamic governance. This involves more than balancing energy, since living things maintain their internal order by controlling transformations of energy, resisting probabilistic trends to more random states. This review will also look at recent research in PD on the analysis of entropy-an information theory metric of predictability in a message-in recordings from the basal ganglia. Close relationships between energy and information converge around the concept of entropy. This is especially relevant to the motor system, which regulates energy exchange with the outside world through its flow of information. The malignant syndrome in PD, a counterpart of neuroleptic malignant syndrome, demonstrates how much thermodynamic disruption can result from breakdown of motor signalling in an extreme hypodopaminergic state. The macroenergetic disturbances of PD are consistent with a unifying hypothesis of dopamine's neurotransmitter actions-to adapt energy expenditure to prevailing economic circumstances.

The Impact of Dietary Intake and Physical Activity on Body Composition in Parkinson's Disease

BACKGROUND

Skeletal muscle loss has been associated with declining physical performance and a negative prognostic effect on falls, disability, and mortality risk in Parkinson's disease.

OBJECTIVES

We aimed to analyze the clinical correlates associated with skeletal muscle wasting in Parkinson's disease.

METHODS

This was a cross-sectional, case-control, observational study. We collected information on dietary intake with a 24-hour recall questionnaire, body composition with bioelectrical impedance, motor severity with the Unified Parkinson's disease Rating Scale, and physical activity with the Global Physical Activity Questionnaire. We used multivariate linear regression analysis to analyze the sociodemographic and clinical correlates associated with skeletal muscle loss after adjusting for confounding variables.

RESULTS

Forty-three patients with Parkinson's disease and 21 matched family members were included. Patients and family members had similar body composition, anthropometrics, and nutritional parameters. Advanced patients had similar nutrient intakes compared to patients with mild-to-moderate Parkinson's disease. In the multivariate linear regression analysis, female patients with low physical activity and low energy intake were more likely to have skeletal muscle loss.

CONCLUSIONS

Skeletal muscle wasting is a complex multifactorial problem. Dietary strategies and physical exercise should be recommended, especially to females with Parkinson's disease, to prevent significant skeletal muscle wasting.

Gastroparesis in Parkinson Disease: Pathophysiology, and Clinical Management

Patients with Parkinson disease (PD) experience a range of non-motor symptoms, including gastrointestinal symptoms. These symptoms can be present in the prodromal phase of the disease. Recent advances in pathophysiology reveal that α-synuclein aggregates that form Lewy bodies and neurites, the hallmark of PD, are present in the enteric nervous system and may precede motor symptoms. Gastroparesis is one of the gastrointestinal involvements of PD and is characterized by delayed gastric emptying of solid food in the absence of mechanical obstruction. Gastroparesis has been reported in nearly 45% of PD. The cardinal symptoms include early satiety, postprandial fullness, nausea, and vomiting. The diagnosis requires an appropriate test to confirm delayed gastric emptying, such as gastric scintigraphy, or breath test. Gastroparesis can lead to malnutrition and impairment of quality of life. Moreover, it might interfere with the absorption of antiparkinsonian drugs. The treatment includes dietary modifications, and pharmacologic agents both to accelerate gastric emptying and relieve symptoms. Alternative treatments have been recently developed in the management of gastroparesis, and their use in patients with PD will be reported in this review.

Body mass index variations in patients with Parkinson's disease treated with levodopa-carbidopa intestinal gel infusion: A case control study versus standard of care and subthalamic nucleus deep brain stimulation

BACKGROUND

Levodopa-carbidopa intestinal gel (LCIG) is an advanced therapy for patients with Parkinson Disease (PD). Weight loss has been pointed out as an adverse event of LCIG infusion.

AIMS OF THE STUDY

To compare weight changes between three groups of PD patients: patients treated with LCIG, patients within the first year of subthalamic deep brain stimulation (STN-DBS) and patients treated exclusively with oral treatment during 1 year of follow up.

METHODS

Patients treated with LCIG were retrospectively matched by age, gender, disease duration and Hoehn and Yahr to patients undergoing STN-DBS and to patients both receiving the standard of care treatment and unwilling advanced therapies (SOC). Clinical features and weight were collected at baseline, and 12 months after introducing the treatment (LCIG and STN-DBS groups) or for one year of treatment (SOC).

RESULTS

Eighteen patients were included in each group. They had no differences in clinical and demographic features, except for cognitive impairment. There was a mean weight (-5.8kg ±6.8) and BMI (-2.1kg/m²±2.6) reduction in the LCIG group after 12 months, while there was a slight weight loss in the SOC (-1.4kg ±3.1) and a weight increase in the STN-DBS group (5.4kg ±4.7). Differences of weight were statistically different between, LCIG and STN-DBS (P<0.001), LCIG and SOC (P=0.002) and STN-DBS and SOC (P<0.001).

CONCLUSIONS

The study shows a significant weight reduction after starting LCIG infusion compared to the other groups. Weight loss should be closely monitored in patients treated with LCIG.

Increased Added Sugar Consumption Is Common in Parkinson's Disease

Objectives: There is limited information about the dietary habits of patients with Parkinson's Disease (PD), or associations of diet with clinical PD features. We report on nutritional intake in an Australian PD cohort.

Methods: 103 PD patients and 81 healthy controls (HCs) completed a validated, semi-quantitative food frequency questionnaire. Food and nutrient intake was quantified, with consideration of micronutrients and macronutrients (energy, protein, carbohydrate, fat, fibre, and added sugar). Participants also completed PD-validated non-motor symptom questionnaires to determine any relationships between dietary intake and clinical disease features.

Results: Mean daily energy intake did not differ considerably between PD patients and HCs (11,131 kJ/day vs. 10,188 kJ/day, p = 0.241). However, PD patients reported greater total carbohydrate intake (279 g/day vs. 232 g/day, p = 0.034). This was largely attributable to increased daily sugar intake (153 g/day vs. 119 g/day, p = 0.003) and in particular free sugars (61 g/day vs. 41 g/day, p = 0.001). PD patients who (1) experienced chronic pain, (2) were depressed, or (3) reported an impulse control disorder, consumed more total sugars than HCs (all p < 0.05). Increased sugar consumption was associated with an increase in non-motor symptoms, including poorer quality of life, increased constipation severity and greater daily levodopa dose requirement.

Conclusions: We provide clinically important insights into the dietary habits of PD patients that may inform simple dietary modifications that could alleviate disease symptoms and severity. The results of this study support clinician led promotion of healthy eating and careful management of patient nutrition as part of routine care.

Weight loss and weight gain in Parkinson disease

INTRODUCTION

Parkinson disease (PD) has been associated with both weight loss and gain in different stages of the disease. Our study aimed to determine the prevalence and associations with weight change over two years based on 3% and 5% weight change.

METHODS

In this longitudinal analysis, weight at baseline and follow-up was used to classify patients into groups of weight loss, stable, and weight gain. Differences between these groups at baseline and then with change over time were tested.

RESULTS

The sample was 668 patients with mean(SD) age 66.1(10) and disease duration 5.3(5.4) years. Using 3% weight change criteria: 32.6% lost, 23.1% gained, and 55.7% had stable weight. Using 5% criteria: 22.6% lost, 15.7% gained, and 61.7% had stable weight. Age was associated with both 3% and 5% change in weight. Other associations with 5% weight change were disease duration, Total and Motor Unified Parkinson's Disease Rating Scale, Older Americans Resource and Services disability, and Hoehn & Yahr staging. The effects of 3% weight loss on Motor UPDRS, IADLs, and depression, and the effects of 5% weight loss on IADLs remained statistically significant when controlling for baseline differences in age, levodopa use, and Total UPDRS.

CONCLUSION

PD patients are more likely to experience 3% than 5% weight change and this lower threshold of weight change was associated with greater disease severity and disability over time. Attention to more subtle weight change may help identify those at greater risk of disability.

24-Hour Levodopa-Carbidopa Intestinal Gel: Clinical Experience and Practical Recommendations

Infusion of levodopa-carbidopa intestinal gel (LCIG; also designated carbidopa-levodopa enteral suspension) for 16 hours is a standard treatment for patients with advanced Parkinson's disease, and clinical observations suggest that 24-hour LCIG infusion may further reduce symptoms. This review provides practical advice on the management of patients transitioning to 24-hour LCIG infusion. We review available clinical data for 24-hour infusion and discuss adjustments to dosing, recommendations for monitoring, and management of patient concerns, based on our clinical experience. Data from multiple studies suggest that LCIG may improve non-motor symptoms. Although few studies have examined 24-hour LCIG infusion, available data indicate that certain patients may benefit from around-the-clock treatment. Studies of 24-hour LCIG infusion are limited by small sample sizes and open-label study designs, which may hamper translation to clinical practice. In our experience, we have found that patients may benefit from 24-hour infusion when reductions in nocturnal symptoms and improvements to quality of sleep are needed. Levodopa-unresponsive freezing of gait or poorly controlled troublesome dyskinesias may also indicate a patient may benefit from 24-hour infusion. Dose adjustments, especially of the nocturnal rate, are typically necessary and, as with 16-hour infusion, patients should be monitored for autonomic dysfunction; overnight wearing off symptoms; weight changes; fluctuations in plasma levels of vitamins B₆/B₁₂, folate, and homocysteine; changes in sleep patterns; or worsening of hallucinations, delusions, and/or nightmares. Available data and our clinical experience suggest that 24-hour LCIG may be warranted among selected patients who have poorly controlled nocturnal fluctuations or early morning "off" symptoms.

Bone Mineral Density and Related Scores in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Parkinson's disease (PD) is the second most common degenerative neurologic disorder in older adults, and increasing attention has been paid to bone health in PD. Although several studies have shown that patients with PD have a lower bone mineral density (BMD) than do non-PD controls, there have been no systematic reviews in recent years.

METHODS

PubMed, Medline, and Web of Science were used to search relevant studies up to May 2020. BMD, BMD T score, and BMD Z score of patients with and without PD were statistically analyzed. Meta-analysis was conducted using Review Manager version 5.3.

RESULTS

This meta-analysis included 17 studies comprising 10,289 individuals. In the meta-analysis, adults with PD had lower total body, total hip, total radius, lumbar spine, total femur, femur neck, right-hand, and left-hand BMD than did non-PD controls. The T score of total body BMD, total hip BMD, total radius BMD, lumbar spine BMD, L1-L4 spine BMD, total femur BMD, and femur neck BMD in adults with PD were lower than those in non-PD controls. Futhermore, the Z score of total body BMD, total hip BMD, total radius BMD, lumbar spine BMD, L1-L4 spine BMD, and femur neck BMD was lower in adults with PD than in non-PD controls.

CONCLUSIONS

Patients with PD had a lower BMD, BMD T score, and BMD Z score compared with non-PD controls. Therefore, clinicians should routinely monitor BMD of patients with PD to prevent falling and fragility fractures in older adults and optimize BMD before surgical treatment of severe spinal deformity caused by PD.

The impact of intestinal microbiota on weight loss in Parkinson's disease patients: a pilot study

Background: There is increasing evidence of the association between microbiome dysfunction and Parkinson's disease (PD). Moreover, some PD patients suffer from unintentional weight loss (WL) which may precede the motor manifestations of the disease. Materials & methods: Gut microbiota profiling by 16S rRNA gene sequencing was performed in PD patients with an unintended WL, in steady weight patients (non-WL [NWL]) and in matched normal subjects. KEGG functional predictions were carried out. Results: Microbiota profiles revealed a dissimilarity between WL and NWL. Moreover, WL pathways were characterized by fatty acid biosynthesis, while NWL by inflammation pathways. Conclusion: The gut microbiota could participate in weight alteration observed in PD by the presence of bacteria involved in weight gain and inflammation, or conversely by bacteria implicated in energy expenditure.

Progressive and accelerated weight and body fat loss in Parkinson's disease: A three-year prospective longitudinal study

INTRODUCTION

Although weight loss is common in Parkinson's disease (PD), longitudinal studies assessing weight and body composition changes are limited.

METHODS

In this three-year longitudinal study, 125 subjects (77 PD patients and 48 spousal/sibling controls) underwent clinical, biochemical and body composition assessments using dual-energy X-ray absorptiometry.

RESULTS

Patients were older than controls (65.6 ± 8.9 vs. 62.6 ± 7.1, P = 0.049), with no significant differences in gender, comorbidities, dietary intake and physical activity. Clinically significant weight loss (≥5% from baseline weight) was recorded in 41.6% of patients, with a doubling of cases (6.5 to 13.0%) classified as underweight at study end. Over three years, patients demonstrated greater reductions in BMI (mean -1.2 kg/m², 95%CI-2.0 to -0.4), whole-body fat percentage (-2.5% points, 95%CI-3.9 to -1.0), fat mass index (FMI) (-0.9 kg/m², 95%CI-1.4 to -0.4), visceral fat mass (-0.1 kg, 95%CI-0.2 to 0.0), and subcutaneous fat mass (-1.9 kg, 95%CI-3.4 to -0.5) than in controls, with significant group-by-time interactions after adjusting for age and gender. Notably, 31.2% and 53.3% of patients had FMI<3rd (severe fat deficit) and <10th centiles, respectively. Muscle mass indices decreased over time in both groups, without significant group-by-time interactions. Multiple linear regression models showed that loss of body weight and fat mass in patients were associated with age, dyskinesia, psychosis and constipation.

CONCLUSIONS

We found progressive loss of weight in PD patients, with greater loss of both visceral and subcutaneous fat, but not muscle, compared to controls. Several associated factors (motor and non-motor disease features) were identified for these changes, providing insights on possible mechanisms and therapeutic targets.

Intrastriatal administration of coenzyme Q10 enhances neuroprotection in a Parkinson's disease rat model

Parkinson's disease is a neurodegenerative disorder, and no treatment has been yet established to prevent disease progression. Coenzyme Q10, an antioxidant, has been considered a promising neuroprotective agent; however, conventional oral administration provides limited efficacy due to its very low bioavailability. In this study, we hypothesised that continuous, intrastriatal administration of a low dose of Coenzyme Q10 could effectively prevent dopaminergic neuron degeneration. To this end, a Parkinson's disease rat model induced by 6-hydroxydopamine was established, and the treatment was applied a week before the full establishment of this disease model. Behavioural tests showed a dramatically decreased number of asymmetric rotations in the intrastriatal Coenzyme Q10 group compared with the no treatment group. Rats with intrastriatal Coenzyme Q10 exposure also exhibited a larger number of dopaminergic neurons, higher expression of neurogenetic and angiogenetic factors, and less inflammation, and the effects were more prominent than those of orally administered Coenzyme Q10, although the dose of intrastriatal Coenzyme Q10 was 17,000-times lower than that of orally-administered Coenzyme Q10. Therefore, continuous, intrastriatal delivery of Coenzyme Q10, especially when combined with implantable devices for convection-enhanced delivery or deep brain stimulation, can be an effective strategy to prevent neurodegeneration in Parkinson's disease.

Altered Body Composition and Increased Resting Metabolic Rate Associated with the Postural Instability/Gait Difficulty Parkinson's Disease Subtype

Background

Weight loss in Parkinson's disease (PD) patients is a common but poorly understood manifestation. Several studies have reported that weight changes could be related to motor symptoms, drug side effects, dysphagia, depression, and/or dementia. Weight loss in PD is not a benign phenomenon and it has several clinical and prognostic implications with increased morbidity and mortality. Thus, it is crucial to determine nutritional changes in PD patients in order to prevent malnutrition and improve their quality of life.

Objective

To compare body composition and resting metabolic rates between PD patients and controls.

Methods

A total of 64 PD patients and 52 controls were studied. The Hoehn-Yahr scale was used to determine the disease stage, clinical and epidemiological data were recorded from verbal questionnaire, Inbody S10® was used to collect corporal parameters, and FitMate system was used to assess the resting metabolic rate.

Results

No significant differences were found between both experimental groups in age, gender, height, cholesterol levels, and the presence of hypertension, diabetes, and hypo/hyperthyroidism. However, the PD group showed lower body fat mass, whole-body fat percentage, and greater resting metabolic rate compared to controls (p < 0.05), with no significant differences in musculoskeletal mass. Parkinson's disease postural instability/gait difficulty (PD-PIGD) subtype showed lower body fat parameters, increased fat-free mass, and higher resting metabolic rates.

Conclusions

These results suggest that PD patients present an increased resting metabolic rate associated with the postural instability/gait difficulty PD subtype, allowing a selective decrease of body fat mass and not musculoskeletal mass. Of note, several disease-related factors may contribute to this weight loss in PD patients, being a complex and multifactorial consequence. Our findings could likely be one of the many contributing factors. However, present findings may further add to our understanding of the phenomenon of weight loss in patients with PD.

A systematic review of body mass gain after deep brain stimulation of the subthalamic nucleus in patients with Parkinson's disease

This systematic review investigated the effects of deep brain stimulation of the subthalamic nucleus on extent and time course of body mass changes in patients with Parkinson's disease. A computerized search identified relevant articles using a priori defined inclusion and exclusion criteria. A descriptive analysis was calculated for the main outcome parameters body mass and BMI. Thirty-eight out of 206 studies fulfilled the inclusion criteria (979 patients aged 59.0±7.5 years). Considering the longest follow-up time for each study, body mass and BMI showed a mean increase across studies of +5.71kg (p < .0001; d = 0.64) and +1.8kg/m² (p < .0001; d = 1.61). The time course of body mass gain revealed a continuous increase ranging from +3.25kg (d = 0.69) at 3 months, +3.88kg (d = 0.21) at 6 months, +6.35kg (d = 0.72) at 12 months, and +6.11kg (d = 1.02) greater than 12 months. Changes in BMI were associated with changes in disease severity (r = 0.502, p = .010) and pharmacological treatment (r = 0.440, p = .0231). Data suggest that body mass gain is one of the most common side effects of deep brain stimulation going beyond normalization of preoperative weight loss. Considering the negative health implications of overweight, we recommend the development of tailored therapies to prevent overweight and associated metabolic disorders following this treatment.

Frontal defect contribution to decreasing of body mass index in Parkinson's disease patients

OBJECTIVE

Weight loss is common in patients with Parkinson's disease (PD). It has been reported that low Body Mass Index (BMI) is associated with disease progression in these patients, but only a few data are available on the relationship between BMI and cognitive dysfunctions in PD patients. In the present study we systematically assessed the possible relationship between BMI index and specific cognitive defects.

METHOD

We enrolled a prospective sample of 37 PD individuals and 30 healthy controls (HC) of similar age, sex, and education. The BMI was calculated in each participant, who underwent a neuropsychological assessment exploring the general cognitive skills, frontal/executive, visuo-spatial, visuo-constructional and memory abilities.

RESULTS

We showed that PD group had significant lower BMI value compared to HC group. In PD patients, the BMI was negatively correlated to disease duration and number of errors at the Stroop-Color Word Test, and positively to score on Frontal Assessment Battery (FAB). Moreover, a regression analysis revealed that, the BMI in PD patients was associated with disease duration and score on FAB.

CONCLUSIONS

Our findings contribute to reveal that the relationship between height and weight is strongly related to frontal cognitive dysfunctions in PD patients.

Body mass index, diabetes, and the risk of Parkinson's disease

BACKGROUND

There are conflicting findings in the literature regarding the association of body mass index and incidence of PD.

OBJECTIVES

This study aimed to investigate the association of body mass index with the risk of PD incidence while considering diabetes mellitus as a major confounding factor.

METHODS

We examined 6,800,601 individuals (aged ≥40 years) who were free of PD using the database of the Korean National Health Insurance Service. Cox proportional hazard regression was used to assess adjusted hazard ratios for PD with adjustment for potential confounders. Stratified analyses by diabetes status were also performed.

RESULTS

A total of 33,443 individuals were diagnosed with PD during the follow-up period (7.3 years). An increased risk of PD incidence was observed in the underweight group versus the normal group (adjusted hazard ratio: 1.28; 95% confidence interval: 1.21-1.36), whereas a decreased risk of PD incidence was observed (adjusted hazard ratio: 0.88; 95% confidence interval: 0.88-0.93) in the obese group and (adjusted hazard ratio: 0.77; 95% confidence interval: 0.72-0.82) in the severely obese group. This association consistently persisted after stratification by diabetes mellitus status, with the steepest downward slope for PD risk present with increasing body mass index in patients with severe diabetes mellitus (i.e., long duration or complication).

CONCLUSIONS

Being underweight and diabetes mellitus were associated with an increased risk of PD incidence, and effect of being underweight was more prominent in those with diabetes mellitus, with a dose-response relationship existing according to diabetes mellitus status. Further research is warranted to understand the clinical implications of the significant interaction between being underweight and diabetes mellitus status in the development of PD. © 2020 International Parkinson and Movement Disorder Society.

Estimation of skeletal muscle mass in patients with spinocerebellar ataxia type 3 and 10

BACKGROUND

Neurodegenerative diseases may progress to a level in which patients present spontaneous weight loss, resulting in increased falls and functional disabilities when the disease is associated with muscle mass depletion.

OBJECTIVE

Evaluate the muscle compartment in patients presenting spinocerebellar ataxia (SCA) type 3 and 10.

METHODS

Forty-six patients presenting SCA type 3 and 10 were assessed and 76 volunteers were selected to the control group. In order to evaluate the muscle compartment, muscle mass anthropometric measurements were assessed and total skeletal muscle mass calculated through a predictive equation.

RESULTS

Women with SCA3 presented greater weight loss and muscle mass reduction compared to those with SCA10 and the control group. Among the predictive measurements, calf muscle circumference showed a more significant correlation with total skeletal muscle mass (p = 0.718).

CONCLUSION

Patients presenting both types of ataxia did not show severe depletion in their nutritional status; however, those with SCA3 displayed greater weight loss and muscle mass reduction compared to the SCA10 group.

Levodopa/carbidopa intestinal gel infusion and weight loss in Parkinson's disease

BACKGROUND AND PURPOSE

Weight loss (WL) is a frequent yet under-recognized complication of levodopa/carbidopa intestinal gel (LCIG) infusion, as well as a milestone of Parkinson's disease (PD) disability progression. The complex association between WL, poor nutritional status, motor complications and PD progression, however, remains unclear.

METHODS

Consecutive consenting patients with PD treated with LCIG (n = 44; PD duration, 18.3 ± 6.5 years) were enrolled in an open-label observational study assessing the extent of WL occurring during LCIG treatment. As secondary aims, we correlated the nutritional status, as detected by the Mini Nutritional Assessment, with the severity of motor symptoms [Movement Disorder Society Unified Parkinson's Disease Rating Scale part III], motor complications (Unified Parkinson's Disease Rating Scale part IV), activities of daily living (Schwab and England scale), cognitive impairment (Mini Mental State Examination), depression (Beck Depression Inventory), difficulties in feeding (Edinburgh Feeding Evaluation in Dementia Questionnaire) and levodopa equivalent daily dose (LEDD).

RESULTS

There was an average WL of 9.9 ± 10.5% (7.6 ± 7.1 kg) over an LCIG treatment period of 51.6 ± 28.5 months. The extent of WL correlated with the percentage of the waking day spent with dyskinesia (P < 0.05). The nutritional status correlated with motor symptom severity (P < 0.01), dysphagia (P < 0.01) and LEDD (P < 0.01).

CONCLUSIONS

Weight loss may occur in patients with PD undergoing LCIG in correlation with the percentage of the waking day spent with dyskinesia. Regardless of the extent of WL, the nutritional status correlated with higher LEDD, as well as with indices of disease progression, such as motor symptom severity and dysphagia.

Parkinson's Disease and Current Treatments for Its Gastrointestinal Neurogastromotility Effects

PURPOSE OF REVIEW

Gastrointestinal disturbances are seen in nearly all patients with Parkinson's disease and lead to impaired quality of life, affect drug pharmacodynamics, and potentially worsen patient's existing motor fluctuations, leading to further disability. Recent evidence links abnormal accumulations of α-synuclein aggregates in the periphery (gut) as seen in the cortex which causes dysfunctions impacting every level of the gastrointestinal tract from the esophagus, to the stomach, small bowel, colon, and rectum and can even predate the onset of the central neurologic disorder itself. Many treatments exist for the clinical phenotypes that result from the autonomic dysfunction and neuropathy involved in this neurodegenerative disorder. The treatments for the gut dysfunction seen in Parkinson's disease (PD) depend on the specific area of the gastrointestinal tract affected. For dysphagia, behavioral therapies with speech pathology, neuromuscular electrical stimulation, or botulinum toxin injection may be helpful. For gastroparesis, domperidone may serve as an antiemetic while also blunting the hypotensive potential of Levodopa while new treatments such as ghrelin agonists may prove beneficial to help appetite, satiety, gastric emptying in those with constipation, and even improve constipation. Antibiotics such as rifaximin with poor systemic absorption may be used to treat small bacterial overgrowth also found in those with PD while the benefits of probiotics is yet to be determined. Finally, constipation in PD can be a reflection of pelvic floor dyssynergia, slow transit constipation, or both, thus treatments targeting the specific anorectal dysfunction is necessary for better outcomes.

Weight Loss in Parkinson's Disease: The Relationship with Motor Symptoms and Disease Progression

Objectives

To determine the prevalence of weight loss (WL) in PD patients, its relationship to the severity of motor manifestations and appetite changes.

Methods

144 PD patients and 120 controls were evaluated in a single session. All subjects were asked about changes in body weight and appetite. PD patients were examined with the UPDRS-III and the Hoehn and Yahr (HY) scales. Subscores of tremor, bradykinesia /rigidity, and non-dopaminergic symptoms (NDS) were analyzed individually. Multivariable logistic regression analysis was used to determine an association between WL and PD motor manifestations.

Results

48.6 % of PD patients presented WL compared to 20.8 % of controls (p < 0.001). Weight losers were significantly older and had longer disease duration, higher scores in HY stages, UPDRS-III, and NDS-subscore. Multivariable logistic regression analysis demonstrated that WL was associated with NDS-subscore (p= 0.002; OR: 1.33) and older age (p= 0.037; OR: 1.05). Appetite in PD cases losing weight was unchanged (35.7 %), decreased (31.4 %), or even increased (32.9).

Conclusions

Our results showed that WL occurs in almost half of PD patients and it is largely the consequence of disease progression rather than involuntary movements or a decrease in food intake.

Altered body composition, sarcopenia, frailty, and their clinico-biological correlates, in Parkinson's disease

INTRODUCTION

Low body weight in Parkinson's disease (PD) is poorly understood despite the associated risks of malnutrition, fractures, and death. Sarcopenia (loss of muscle bulk and strength) and frailty are geriatric syndromes that are likewise associated with adverse health outcomes, yet have received scant attention in PD. We studied body composition, sarcopenia, frailty, and their clinico-biological correlates in PD.

METHODS

93 patients and 78 spousal/sibling controls underwent comprehensive assessment of diet, clinical status, muscle strength/performance, frailty, body composition (using dual-energy X-ray absorptiometry), and serum levels of neurogastrointestinal hormones and inflammatory markers.

RESULTS

PD patients were older than controls (66.0 ± 8.5 vs. 62.4 ± 8.4years, P = 0.003). Mean body mass index (24.0 ± 0.4 vs. 25.6 ± 0.5kg/m2, P_adjusted = 0.016), fat mass index (7.4 ± 0.3 vs. 9.0 ± 0.3kg/m2, P_adjusted<0.001), and whole-body fat percentage (30.7 ± 0.8 vs. 35.7 ± 0.9%, P_adjusted<0.001) were lower in patients, even after controlling for age and gender. There were no between-group differences in skeletal muscle mass index and whole-body bone mineral density. Body composition parameters did not correlate with disease duration or motor severity. Reduced whole-body fat percentage was associated with higher risk of motor response complications as well as higher levels of insulin-growth factor-1 and inflammatory markers. PD patients had a higher prevalence of sarcopenia (17.2% vs. 10.3%, P_adjusted = 0.340) and frailty (69.4% vs. 24.2%, P_adjusted = 0.010). Older age and worse PD motor severity were predictors of frailty in PD.

CONCLUSIONS

We found reduced body fat with relatively preserved skeletal muscle mass, and a high prevalence of frailty, in PD. Further studies are needed to understand the patho-mechanisms underlying these alterations.

Repurposing drugs to treat l-DOPA-induced dyskinesia in Parkinson's disease

In this review, we discuss the opportunity for repurposing drugs for use in l-DOPA-induced dyskinesia (LID) in Parkinson's disease. LID is a particularly suitable indication for drug repurposing given its pharmacological diversity, translatability of animal-models, availability of Phase II proof-of-concept (PoC) methodologies and the indication-specific regulatory environment. A compound fit for repurposing is defined as one with appropriate human safety-data as well as animal safety, toxicology and pharmacokinetic data as found in an Investigational New Drug (IND) package for another indication. We first focus on how such repurposing candidates can be identified and then discuss development strategies that might progress such a candidate towards a Phase II clinical PoC. We discuss traditional means for identifying repurposing candidates and contrast these with newer approaches, especially focussing on the use of computational and artificial intelligence (AI) platforms. We discuss strategies that can be categorised broadly as: in vivo phenotypic screening in a hypothesis-free manner; in vivo phenotypic screening based on analogy to a related disorder; hypothesis-driven evaluation of candidates in vivo and in silico screening with a hypothesis-agnostic component to the selection. To highlight the power of AI approaches, we describe a case study using IBM Watson where a training set of compounds, with demonstrated ability to reduce LID, were employed to identify novel repurposing candidates. Using the approaches discussed, many diverse candidates for repurposing in LID, originally envisaged for other indications, will be described that have already been evaluated for efficacy in non-human primate models of LID and/or clinically. This article is part of the Special Issue entitled 'Drug Repurposing: old molecules, new ways to fast track drug discovery and development for CNS disorders'.

Flavor perception and the risk of malnutrition in patients with Parkinson's disease

Flavor perception involves both olfactory and gustatory function. In patients with Parkinson’s disease (PD), hyposmia is a frequent finding, as well as an increased risk of malnutrition. We performed a pilot study to investigate the relationship between flavor perception and risk of malnutrition in PD patients. 63 PD patients participated to perform an olfactory (Sniffin’ Sticks) and gustatory (Taste Strips) task, and a questionnaire to establish nutritional risk (MUST), which includes BMI measurements. The relationship between olfactory and gustatory function and BMI was analyzed using partial correlations, corrected for disease duration, and regression analysis. Patients displayed a high prevalence of hyposmia (68.3%), and a low prevalence (6.3%) of hypogeusia. A small, but significant correlation was found between olfactory function and BMI (r = 0.261, p = 0.038), and not for gustatory function and BMI (r = 0.137, p = 0.284). Hyposmia, and not hypogeusia, may contribute to weight loss in Parkinson’s disease, and hence increase the risk of malnutrition.

Does reduced mastication influence cognitive and systemic health during aging?

There is a growing body of literature which suggests that oral health and mastication can influence cognitive and systemic health during aging. However, it is currently unclear whether oral health, masticatory efficiency, cognitive health and systemic health merely deteriorate independently with age, or whether mechanisms exist linking mastication to cognitive and systemic health directly. The aim of this paper is to review the extent to which reduced mastication influences cognitive and systemic health during aging because this knowledge may underpin future interventions that improve quality of life. Current evidence suggests that a deterioration in mastication and oral health during aging can have: 1) direct effects on systemic health through mechanisms such as the migration of the oral microbiota into the systemic environment, and 2) indirect effects on systemic health through changes nutrient intake. A loss of teeth and reduction in masticatory efficiency during aging can have: 1) direct effects on cognitive performance and potentially impact cognitive health through mechanisms such as enhanced adult hippocampal neurogenesis, and 2) indirect effects on cognitive health through changes in nutrient intake. It is concluded that oral health and masticatory efficiency are modifiable factors which influence the risk poor cognitive and systemic health during aging, although it is currently premature to propose chewing-based interventions to slow the rate of cognitive decline and improve cognitive health during aging. Future research should include large-scale longitudinal studies which control for the types of confounding factors which concurrently influence the association between mastication and cognitive and systemic health.

Weight Loss and Malnutrition in Patients with Parkinson's Disease: Current Knowledge and Future Prospects

Parkinson's Disease (PD) is currently considered a systemic neurodegenerative disease manifested with not only motor but also non-motor symptoms. In particular, weight loss and malnutrition, a set of frequently neglected non-motor symptoms, are indeed negatively associated with the life quality of PD patients. Moreover, comorbidity of weight loss and malnutrition may impact disease progression, giving rise to dyskinesia, cognitive decline and orthostatic hypotension, and even resulting in disability and mortality. Nevertheless, the underlying mechanism of weight loss and malnutrition in PD remains obscure and possibly involving multitudinous, exogenous or endogenous, factors. What is more, there still does not exist any weight loss and malnutrition appraision standards and management strategies. Given this, here in this review, we elaborate the weight loss and malnutrition study status in PD and summarize potential determinants and mechanisms as well. In conclusion, we present current knowledge and future prospects of weight loss and malnutrition in the context of PD, aiming to appeal clinicians and researchers to pay a closer attention to this phenomena and enable better management and therapeutic strategies in future clinical practice.

Increased energy expenditure during posture maintenance and exercise in early Parkinson disease

BACKGROUND

Evidence for the effects of Parkinson disease on energy expenditure is incomplete and contradictory. A number of studies showed increased resting energy expenditure among patients with Parkinson disease whereas others did not. It was hypothesized that energy expenditure increases during exercise, based on findings in patients with a variable regime of anti-parkinsonian therapies and at different stages of the disease. However, energy expenditure during posture maintenance has been neglected. To better understand these issues, we studied energy expenditure in a homogenous population of Parkinson patients in an early stage of the disease and different states of activity.

METHODS

Oxygen consumption was assessed in a group of 10 males with early Parkinson disease without dopaminergic treatment and controls matched for age and body composition. Oxygen consumption was measured at rest, during trunk unsupported sitting, and during exercise at different intensities (unloaded and loaded cycling).

RESULTS

Resting energy expenditure was similar between groups. Higher energy consumption was observed during maintenance of trunk posture at rest and during light intensity aerobic exercise (P < .05 for all conditions). The increment in energy expenditure associated with increased physical demand tended to be steeper in Parkinson disease.

CONCLUSION

Resting energy expenditure is normal in Parkinson disease. However, energy expenditure increases during physical activity and even during the maintenance of unsupported posture among patients with Parkinson disease.

Technical Note: Preemptive Surgical Revision of Impending Deep Brain Stimulation Hardware Erosion

BACKGROUND

While deep brain stimulation (DBS) is a relatively safe procedure, skin erosion is a commonly reported hardware complication that can threaten the DBS system. Patients with Parkinson disease are especially at risk for this complication due to their autonomic dysregulation and impaired nutrition. Early detection of impending skin erosion allows for intervention that may prevent hardware destruction. Here we report a novel technique to address this complication preemptively. We describe the use of an acellular dermal matrix to prevent skin erosion in 20 patients with Parkinson disease who were treated with DBS and showed signs of impending skin erosion.

METHODS

Twenty patients with signs of impending hardware erosion were identified. An acellular dermal matrix was surgically placed under the at-risk skin overlying the DBS lead.

RESULTS

None of the 20 patients treated with this technique went on to require further revision surgery or removal of hardware.

CONCLUSIONS

Surgical placement of acellular dermal matrix in patients identified as having impending hardware erosions is a safe and cost-effective way to prevent hardware complications.

Objectively Assessed Physical Activity and its Association with Balance, Physical Function and Dyskinesia in Parkinson's Disease

BACKGROUND

The desirable effects of physical activity in individuals with Parkinson's disease are well-known, although according to results from previous studies factors associated with objectively assessed physical activity are not fully investigated.

OBJECTIVE

To investigate demographic, disease-related and mobility-related factors that associate with objectively measured physical activity, in a sample of older adults with mild to moderate Parkinson's disease.

METHODS

Demographic, disease-related and mobility-related factors were gathered by interview from a total of 91 older adults with Parkinson's disease, followed by an evaluation of balance control using the Mini-BESTest. After initial testing, participants wore a tri-axial accelerometer during a week of free-living. Correlation analysis and multiple linear regression was used to investigate factors associated with total PA, represented by total activity counts, and time in brisk walking.

RESULTS

Motor impairment, physical function, body mass index and dyskinesia contributed to the variance of total physical activity, explaining 34 % of the variance, while physical function and balance control were significant factors associated with brisk walking, explaining 22 %.

CONCLUSIONS

This study identified factors that have not been shown to associate with objectively measured physical activity previously, such as dyskinesia, balance control and self-rated physical function. The findings also demonstrated that associated factors differ, depending on the activity behavior being investigated. However, other factors than those included in this study may also be of importance.

Predictors of weight loss in early treated Parkinson's disease from the NET-PD LS-1 cohort

Weight loss is a common symptom of Parkinson's disease and is associated with impaired quality of life. Predictors of weight loss have not been studied in large clinical cohorts. We previously observed an association between change in body mass index and change in Unified Parkinson's Disease Rating Scale (UPDRS) motor and total scores. In this study, we performed a secondary analysis of longitudinal data (1-6 years) from 1619 participants in the NINDS Exploratory Trials in PD Long-term Study-1 (NET-PD LS1) to explore predictors of weight loss in a large prospective clinical trial cohort of early treated Parkinson's disease. The NET-PD LS1 study was a double-blind randomized placebo controlled clinical trial of creatine monohydrate 10 gm/day in early treated PD (within 5 years of diagnosis and within 2 years of starting dopaminergic medications). Linear mixed models were used to estimate the effect of baseline clinical covariates on weight change over time. On average, participants lost only 0.6 kg per year. Higher age, baseline weight, female gender, higher baseline UPDRS scores, greater postural instability, difficulty eating and drinking, lower cognitive scores and baseline levodopa use (compared to dopamine agonists) were all associated with weight loss. Surprisingly baseline difficulty swallowing, dyskinesia, depression, intestinal hypomotility (constipation) and self-reported nausea/vomiting/anorexia were not significantly associated with weight loss in this cohort of early treated Parkinson's disease patients. On average, participants with Parkinson's disease experience little weight loss during the first 1-6 years after starting dopaminergic replacement therapy, however levodopa use and postural instability were both predictors of early weight loss. Trial Registration clinicaltrials.gov identifier# NCT00449865.

Weight in Parkinson's Disease: Phenotypical Significance

Body weight in Parkinson's disease (PD) is a significant nonmotor feature. Weight homeostasis is a complex physiological process and gets deranged in PD patients leading to changes in weight. While both the low and high body weight have been reported as risk factors for PD, the majority of PD patients have a lower weight and a subset of patients lose weight during the course of the disease, while a small proportion gain weight. A number of clinical parameters such as older age, impaired cognition, severity of disease, and an imbalance of food intake determined by satiety and hunger hormones have been reported to be associated with but not the cause of weight change. Low body weight and weight loss have a negative impact on disease severity, dyskinesia quality of life, and mortality indicative of disease progression. An early assessment of olfactory impairment seems to identify patients at risk of weight loss, the patients with more severe olfactory loss-anosmic group, lose weight as compared to the patients with some preservation of olfaction, the hyposmic group. Higher levodopa dose per kilogram body weight increases the risk of dyskinesia, higher body weight seems to be protective against this complication. The identification of PD patients according to the nonmotor phenotype of "Park-olfaction-weight-phenotype" and the "olfaction-weight-dyskinesia" triad should help to develop strategies to prevent weight reduction and improve general health and complications of PD patients. The phenotype seems to reflect a differential prodromal pathology and influence clinical disease. Higher body weight patients would benefit from life style changes to achieve a healthy profile. Weight monitoring and weight orientated approach to management of PD patients should help to improve their outcome. Body weight change might be a surrogate to disease progression and may be used to investigate neuroprotection strategies.

Subthalamic Nucleus Deep Brain Stimulation in Early Stage Parkinson's Disease Is Not Associated with Increased Body Mass Index

Previous studies suggest that deep brain stimulation of the subthalamic nucleus (STN-DBS) for Parkinson's disease (PD) leads to weight gain. This study analyzes changes in body mass index (BMI) in 29 subjects from a prospective, single-blind trial of DBS in early stage PD (age 50–75, Hoehn & Yahr stage II off medication, treated with antiparkinsonian medications for ≥6 months but <4 years, and without a history of motor fluctuations, dyskinesias, or dementia). Subjects were randomized to DBS plus optimal drug therapy (DBS+ODT; n = 15) or ODT (n = 14) and followed for 24 months. Weight and height were recorded at baseline and each follow-up visit and used to calculate BMI. BMIs were compared within and between groups using nonparametric t-tests. Mean BMI at baseline was 29.7 in the ODT group and 32.3 in the DBS+ODT group (p > 0.05). BMI change over two years was not different between the groups (p = 0.62, ODT = −0.89; DBS+ODT = −0.17). This study suggests that STN-DBS is not associated with weight gain in subjects with early stage PD. This finding will be tested in an upcoming FDA-approved phase III multicenter, randomized, double-blind, placebo-controlled, pivotal clinical trial evaluating DBS in early stage PD (ClinicalTrials.gov identifier NCT00282152).

A multifactorial study on nutritional status, binge eating and physical activity as main factors directly influencing body weight in Parkinson's disease

Weight lossisa multifactorial disorder commonly affecting Parkinson's disease patients. The aim of this study was to investigate the relationship between body weight, nutritional status, physical activity, and Parkinson's disease-related factors. A total of 114 consecutive Parkinson's disease patients without dietary restrictions were evaluated prospectively with respect to: nutritional status (Mini Nutritional Assessment), physical activity level (Yale Physical Activity Survey), MDS-UPDRS score, olfactory function, depression, cognitive functionand impulse-control disorders, among other variables. Structural equation modeling was used to build multivariate models and to calculate standardized regression weights (srw) for pairs of variables, which are homologous to correlation coefficients, taking into account the effects of all other variables in the model. Sixty (53%) patients were males. Mean age was 66.1 ± 9.8 years and mean disease duration was 8.3 ± 5.6 years. Longer disease duration was negatively related to nutritional status (srw = -0.25; p = 0.01). UPDRS II + III score was associated with reduced cognitive function (srw = -0.39; p = 0.01), which was positivelyrelated to nutritional status (srw = 0.23; p = 0.01). Finally, nutritional status was positively related to body weight (srw = 0.22, p < 0.01). Binge eating and physical activity were also directly and positively related to body weight (srw = 0.32; p = 0.001 and srw = 0.23; p = 0.001). Nutritional status, binge eating and physical activity were directly and independently related to body weight in our sample of Parkinson's disease patients. Therefore, physicians should actively explore nutritional status and binge eating in Parkinson's disease patients to avoid alterations in body weight regulation. Effects of physical activity should be further explored.