Can we add whey protein supplementation in patients with Parkinson's disease without interfering with levodopa response?

OBJECTIVE

The main endpoint of the study was to evaluate if a daily intake of whey protein-based dietary supplement causes a worse response to levodopa in people with Parkinson's Disease (PWPD).

BACKGROUND

In PWPD, the competition between large neutral aminoacids and levodopa at intestinal absorption level may interfere with dopaminergic therapy's (DRT) effect; therefore, protein redistribution dietary regimen has been suggested. Many dietary supplementations are available to help people in balancing the protein intake and overcoming muscle mass loss. However, most of the products contain protein and could potentially affect levodopa action in PWPD.

METHODS

We performed a randomised single blind monocentric study on PWPD admitted in the rehabilitative unit for a 4-week multidisciplined intensive aerobic rehabilitation treatment. All patients received a standard protein redistribution dietary regimen plus a whey protein-based oral formula (N = 26) or Magnesium (N = 25) twice daily for 28 days. Neurological assessment and physical evaluation were conducted before (T0) and after (T1) rehabilitative treatment; DRT was recorded T0 and T1 as well. The delta of changes within groups in neurological (UPDRS III) and physical (TUG, 6 MW) evaluation scales was compared between groups.

RESULTS

Groups were comparable at baseline in clinical and demographic data; at T1, both groups showed a decrease in UPDRS III, TUG and 6 MWT and no differences between deltas were found. DRT remained stable in both groups.

CONCLUSIONS

Our results show that whey protein supplementation does not interfere with DRT's efficacy and can be used in PWPD who need a protein supplementation without restrictions in intake hours.

Genetic Markers as Risk Factors for the Development of Impulsive-Compulsive Behaviors in Patients with Parkinson's Disease Receiving Dopaminergic Therapy

Impulsive–compulsive and related behavioral disorders (ICD) are drug-induced non-motor symptoms of Parkinson’s disease (PD). Recently research has focused on evaluating whether ICD could be predicted and managed using a pharmacogenetic approach based on dopaminergic therapies, which are the main risk factors. The aim of our study was to evaluate the role of candidate genes such as DBH, DRD2, MAOA, BDNF, COMT, SLC6A4, SLC6A3, ACE, DRD1 gene polymorphisms in the pathogenesis of ICD in PD. We compared patients with PD and ICD (n = 49), patients with PD without ICD (n = 36) and a healthy control group (n = 365). ICD was diagnosed using the QUIP questionnaires and specific diagnostic criteria for subtypes of ICD. Genotyping was conducted using a number of PCR techniques and SNaPshot. Statistical analysis was performed using WinPepi and APSampler v3.6 software. PCA testing was conducted using RStudio software v1.4.1106-5. The following substitutions showed statistically significant correlations with PD and ICD: DBH (rs2097629, rs1611115), DRD2 (rs6275, rs12364283, rs1076560), ACE (rs4646994), DRD1 (rs686), BDNF (rs6265), these associations are novel in Russian PD patients. Our findings suggest that polymorphisms in DBH, BDNF, DRD2, ACE genes in Russian subjects are associated with an increased risk of ICD development.

[Unusual failure of swimming skills in patients with Parkinson's disease]

The results of individual observations and several studies confirm the frequent complaints of patients with Parkinson's disease (PD) about difficulty or inability to swim. Difficulties moving the limbs, coordination and maintaining the horizontal position during swimming appear to be the main problems that prevent normal swimming. Further studies are needed to assess the frequency of swimming disorders in PD and the mechanisms of their development. Patients with PD must be educated about the potential risk of drowning and the need to evaluate and carefully monitor their swimming skills before going into deep water.

Neurophysiological Predictors of Response to Medication in Parkinson's Disease

Background: Although dopaminergic medication has been the foundation of Parkinson's disease (PD) therapy for decades, sensitive and specific therapeutic response biomarkers that allow for better treatment optimization are lacking. Objective: We tested whether the features of Transcranial Magnetic Stimulation-based neurophysiological measures taken off-medication are associated with dopaminergic medication-induced clinical effects. Method: Motor cortex excitability [short-latency intracortical inhibition (SICI), intracortical facilitation (ICF), short-latency afferent inhibition (SAI), and input-output (IO) curve], and plasticity [paired associative stimulation (PAS) protocol] neurophysiological measures were examined in 23 PD patients off-medication. Clinical features were quantified by the motor section of the Unified Parkinson's Disease Scale (total score and lateralized total, bradykinesia, and rigidity sub-scores), and the differences between measures off-medication and on-medication (following the usual morning dose), were determined. Total daily dopaminergic medication dose (expressed as levodopa equivalent daily dose-LEDD), was also determined. Results: SICI significantly correlated with changes in lateralized UPDRS motor and bradykinesia sub-scores, suggesting that patients with stronger basal intracortical inhibition benefit more from dopaminergic treatment than patients with weaker intracortical inhibition. Also, ICF significantly negatively correlated with LEDD, suggesting that patients with stronger intracortical facilitation require less dopaminergic medication to achieve optimal therapeutic benefit. Both associations were independent of disease severity and duration. Conclusions: The results suggest variability of (patho) physiological phenotypes related to intracortical inhibitory and facilitatory mechanisms determining clinical response to dopaminergic medication in PD. Measures of intracortical excitability may help predict patients' response to dopaminergic therapy, thus potentially providing a background for developing personalized therapy in PD.

Dopamine effects on memory load and distraction during visuospatial working memory in cognitively normal Parkinson's disease

Visuospatial working memory (WM) impairments in Parkinson's disease (PD) are more prominent and evolve earlier than verbal WM deficits, suggesting some differences in underlying pathology. WM is regulated by dopaminergic neurotransmission in the prefrontal cortex, but the effect of dopamine on specific processes supporting visuospatial WM are not well understood. Dopamine therapeutic effects on different WM processes may also differ given the heterogeneity of cognitive changes in PD. The present study examined the effect of dopamine therapy on memory load and distraction during visuospatial WM. Exploratory analyses evaluated whether individual differences in medication effects were associated with a gene, catechol-O-methyltransferase (COMT), which regulates prefrontal cortex dopamine levels. Cognitively normal PD participants (n = 28) and controls (n = 25) performed a visuospatial WM task, which manipulated memory load and the presence/absence of distractors. PD participants performed the task on and off medication. PD COMT groups were comprised of Met homozygote (lower COMT activity) and heterozygote and Val homozygote carriers (higher COMT activity, Het/Val). The results showed that handling higher memory loads and suppressing distraction were impaired in PD off, but not on medication. Medication improved distraction resistance in Met, but not Het/Val group. COMT did not modulate medication effects on memory load. These findings demonstrate that dopaminergic therapy restores visuospatial WM processes in patients without cognitive impairment and suggest that COMT variants may partly explain the mixed effects of medication on specific processes governed by distinct brain systems. Future investigations into gene-modulated effects of medication could lead to individualized strategies for treating cognitive decline.

Pharmacological interventions in corticobasal degeneration: a review

Corticobasal degeneration (CBD) is a sporadic tauopathy that presents with a varied combination of motor, cognitive, and behavioral features, making its diagnosis difficult. CBD has high morbidity and poor prognosis, with no effective therapy at present. We searched the PubMed/MEDLINE database for articles published from 1990 to 2019, using the keywords “corticobasal degeneration” AND “treatment.” The PRISMA method was adopted. Retrieved articles were characterized as having one of two methodological approaches: (1) studies aimed at primary tauopathy treatment and (2) symptomatic management. Review articles (based on CBD expert groups), case reports, case series, and pilot clinical trials were selected. Few attempts have been made to study drug options and drug efficacy in CBD systematically, and an effective treatment is not yet available. Treatment is symptomatic and based on similarity with other diseases due to the scarcity of studies specifically addressing CBD. CBD seems not to spark interest in more clinical trials for its low prevalence and reliability in clinical diagnosis.

What Determines Spontaneous Physical Activity in Patients with Parkinson's Disease?

Physical activity (PA) is a factor that may have an influence on the symptoms of Parkinson's disease (PD). The aim of this study was to identify the potential determinants of spontaneous PA in a PD patient group. A total of 134 PD patients aged 65.2 ± 9.2 years with a Hoehn-Yahr scale score ≤4 and a Mini Mental State Examination (MMSE) score ≥24 were examined. For the study's purposes, the authors analyzed age, sex, education, history of PD, dopaminergic treatment, the severity of PD symptoms using Unified Parkinson's Disease Rating Scale (UPDRS), and Hoehn-Yahr scale. Additionally, all participants were evaluated through a set of scales for specific neuropsychiatric symptoms including depression, anxiety, apathy, fatigue, and sleep disorders. A linear regression analysis was used with backward elimination. In the total explanatory model, for 12% of the variability in activity (R² = 0.125; F(16.133) = 2.185; p < 0.01), the significant predictor was starting therapy with the dopamine agonist (DA) (β= 0.420; t= 4.068; p = 0.000), which was associated with a longer duration of moderate PA. In the total explanatory model, for more than 13% of the variance in time spent sitting (R² = 0.135; F(16.130) = 2.267; p < 0.01), the significant predictors were secondary education and the results of the UPDRS. The patients with secondary and vocational education, those starting treatment with DA and those with a less severe degree of Parkinson's symptoms (UPDRS), spent less time sitting in a day. It is possible to identify determinants of spontaneous PA. It may elucidate consequences in terms of influence on modifiable conditions of PA and the proper approach to patients with unmodifiable PA factors.

Resting energy expenditure in Parkinson's disease patients under dopaminergic treatment

Background: Weight homeostasis is complex in Parkinson's disease (PD) and body weight changes substantially throughout the course of the disease. We designed a case-control study to (i) investigate whether PD is associated with changes in resting energy expenditure (REE), (ii) to assess how accurately REE could be predicted for individuals with PD utilizing the equations constructed for healthy individuals, and (iii) to eventually construct a new equation.Materials & Methods: Measured REE (mREE) was compared between 122 PD patients and 122 gender and body mass index (BMI)-matched controls. The accuracy of estimated REE by 5 common equations (Harris/Benedict-1919, Roza/Shizgal-1984, Mifflin St. Jeor, WHO/FAO and aggregate formula) was investigated in PD using Bland-Altman analysis and reported as the frequency of accurate predictions (±10%). Concordance correlation coefficients (CCC) were also calculated. Then, we regressed a new REE equation - using gender, age, weight, height and Hoehn-Yahr stage - and validated it in an independent sample (N = 100).Results: No significant difference in mREE was recorded between the whole PD sample and healthy controls. However, mREE was increased in patients with BMI ≥ 30 kg/m² and Hoehn-Yahr stage ≥ 3. Limited accuracy was present in the available REE equations (accurate prediction [±10%] frequency, <60% for all). For the new equation, the proportion of accurate prediction was 67.0% (overestimation, 24.0%) and CCC was 0.77.Conclusion: PD patients are not commonly characterized by an increase in REE. This is limited to patients suffering from obesity and more severe disease. Common REE equations appear to be inaccurate. The new predictive equation proposed in this study provided better REE estimates.

[Therapeutic and pharmacologic perspectives in Parkinson's disease]

Therapeutic and pharmacologic perspectives in parkinson's disease. Despite the dopaminergic therapy which improves motor symptoms, there are still a lot of challenges to be fulfilled in Parkinson's disease. Dopamine replacement therapy is hampered by motor complications, has no efficacy on non-motor symptoms, and is not neuroprotective so does not change disease progression. Second line therapies, also mainly acting on motor symptoms, such as deep brain stimulation, and continuous administration of levodopa or apomorphine by pumps, can benefit to a limited number of patients but are associated with a high burden for the patients and their caregivers, and a high cost for society. Several therapeutic strategies are currently under evaluation to improve the treatment of motor fluctuations, dyskinesia, and some non-motor symptoms. The recent development of more predictive preclinical models and biomarkers of disease progression should allow fostering the development of innovative neuroprotective strategies. The stratification of patients through the combination of clinical, biological and brain imaging features will help to move towards personalized precision medicine by matching patients care to their individual progression profile.

Dopaminergic Therapy Increases Go Timeouts in the Go/No-Go Task in Patients with Parkinson's Disease

Parkinson's disease (PD) is characterized by resting tremor, rigidity and bradykinesia. Dopaminergic medications such as L-dopa treat these motor symptoms, but can have complex effects on cognition. Impulse control is an essential cognitive function. Impulsivity is multifaceted in nature. Motor impulsivity involves the inability to withhold pre-potent, automatic, erroneous responses. In contrast, cognitive impulsivity refers to improper risk-reward assessment guiding behavior. Informed by our previous research, we anticipated that dopaminergic therapy would decrease motor impulsivity though it is well known to enhance cognitive impulsivity. We employed the Go/No-go paradigm to assess motor impulsivity in PD. Patients with PD were tested using a Go/No-go task on and off their normal dopaminergic medication. Participants completed cognitive, mood, and physiological measures. PD patients on medication had a significantly higher proportion of Go trial Timeouts (i.e., trials in which Go responses were not completed prior to a deadline of 750 ms) compared to off medication (p = 0.01). No significant ON-OFF differences were found for Go trial or No-go trial response times (RTs), or for number of No-go errors. We interpret that dopaminergic therapy induces a more conservative response set, reflected in Go trial Timeouts in PD patients. In this way, dopaminergic therapy decreased motor impulsivity in PD patients. This is in contrast to the widely recognized effects of dopaminergic therapy on cognitive impulsivity leading in some patients to impulse control disorders. Understanding the nuanced effects of dopaminergic treatment in PD on cognitive functions such as impulse control will clarify therapeutic decisions.

Automatic Online Motor Control Is Intact in Parkinson's Disease With and Without Perceptual Awareness

In the double-step paradigm, healthy human participants automatically correct reaching movements when targets are displaced. Motor deficits are prominent in Parkinson's disease (PD) patients. In the lone investigation of online motor correction in PD using the double-step task, a recent study found that PD patients performed unconscious adjustments appropriately but seemed impaired for consciously-perceived modifications. Conscious perception of target movement was achieved by linking displacement to movement onset. PD-related bradykinesia disproportionately prolonged preparatory phases for movements to original target locations for patients, potentially accounting for deficits. Eliminating this confound in a double-step task, we evaluated the effect of conscious awareness of trajectory change on online motor corrections in PD. On and off dopaminergic therapy, PD patients (n = 14) and healthy controls (n = 14) reached to peripheral visual targets that remained stationary or unexpectedly moved during an initial saccade. Saccade latencies in PD are comparable to controls'. Hence, target displacements occurred at equal times across groups. Target jump size affected conscious awareness, confirmed in an independent target displacement judgment task. Small jumps were subliminal, but large target displacements were consciously perceived. Contrary to the previous result, PD patients performed online motor corrections normally and automatically, irrespective of conscious perception. Patients evidenced equivalent movement durations for jump and stay trials, and trajectories for patients and controls were identical, irrespective of conscious perception. Dopaminergic therapy had no effect on performance. In summary, online motor control is intact in PD, unaffected by conscious perceptual awareness. The basal ganglia are not implicated in online corrective responses.

Creative Thinking, Professional Artists, and Parkinson's Disease

BACKGROUND

An increase in artistic-like production in Parkinson's disease (PD) has been associated with compulsive and repetitive behaviours after the introduction of dopaminergic treatment (DT). Recent data suggest that it could be due to the emergence of artistic-like skills triggered by DT.

OBJECTIVE

In order to evaluate whether artistic production and creative thinking are influenced by DT or linked to artistic-like skills, we characterize creativity features in PD and healthy controls (HC) including professional artists.

METHODS

Three groups of PD out-patients were included consecutively: professional artists (PD-A), patients with (PD-C) and without artistic-like production (PD-NC). Twenty-four gender and age-matched HC were included: professional artists (HC-A) and non-artists (HC-NC). All patients were evaluated by means of a) a battery of neuropsychological tests and a semi-structured interview; b) the Abbreviated Torrance Test for Adults (ATTA) for creative thinking; c) the Minnesota Impulsive Disorders Interview (mMIDI) and a screening for impulse control disorders (ICDs) for compulsive behaviour.

RESULTS

ATTA total score was significantly higher in HC-A and PD-A than in the other groups. Although PD-NC showed the lowest ATTA total score the difference vs HC-NC was not significant. ATTA scores were not significantly correlated with DT dosage and duration. mMIDI tests were positive only in PD. There were no differences in ICDs among PD groups.

CONCLUSIONS

Our results do not support a relationship between DT and the emergence of artistic creativity. We believe that DT may increase the drive to create and that further studies in "on" and "off" medication are needed to clarify this issue.

Levodopa reverse stridor and prevent subsequent endotracheal intubation in Parkinson disease patients with bilateral vocal cord palsy: A case report

BACKGROUND

Respiratory abnormalities are often overlooked; however, because of their potential comorbidity, they must be analyzed to determine the most effective treatment for patients with Parkinson disease (PD). Among various theories on respiratory abnormalities in PD, "upper airway obstruction" and "restrictive respiratory disorders" are 2 of the most accepted etiologies; both appear to be related to basal ganglia dysfunction. Complex vocal cord muscle dysfunction contributes to stridor, which can be a manifestation of nigrostriatal dopaminergic dysfunction. Stridor is a lethal form of upper airway obstruction in PD patients; its most frequent causes are bilateral vocal cord palsy, laryngeal spasms, and dystonia of the supra-laryngeal muscle. Several previous studies have suggested that levodopa administration induces a significant improvement of both lung function and symptoms of parkinsonian syndrome.

CASE SUMMARY

We reported a 77-year-old gentleman PD patient admitted for acute levodopa-responsive stridor resulting from bilateral vocal cord palsy. Dopaminergic therapy prevented the need for subsequent endotracheal intubation and tracheostomy treatment.

CONCLUSION

It is vital to understand that complex vocal cord muscle dysfunction may be related to nigrostriatal dopaminergic dysfunction in PD patients. The strategy of levodopa up-titration should be considered an option because it may be beneficial in relieving both stridor and parkinsonian syndrome, and in preventing respiratory failure.

Restless nocturnal eating: a common feature of Willis-Ekbom Syndrome (RLS)

STUDY OBJECTIVES

To determine the frequency of nocturnal eating (NE) and sleep related eating disorder (SRED) in restless legs syndrome (RLS) versus psychophysiological insomnia (INS), and the relationship of these conditions with dopaminergic and sedative-hypnotic medications.

DESIGN

Prospective case series.

SETTING

Sleep disorders center.

PATIENTS

Newly diagnosed RLS or INS.

INTERVENTION

RLS or INS pharmacotherapy with systematic follow up interview for NE/SRED.

MEASUREMENTS AND RESULTS

Patients presenting with RLS (n = 88) or INS (n = 42) were queried for the presence of NE and SRED. RLS patients described nocturnal eating (61%) and SRED (36%) more frequently than INS patients (12% and 0%; both p < 0.0001). These findings were not due to arousal frequency, as INS patients were more likely to have prolonged nightly awakenings (93%) than RLS patients (64%; p = 0.003). Among patients on sedative-hypnotics, amnestic SRED and sleepwalking were more common in the setting of RLS (80%) than INS (8%; p < 0.0001). Further, NE and SRED in RLS were not secondary to dopaminergic therapy, as RLS patients demonstrated a substantial drop (68% to 34%; p = 0.0026) in the frequency of NE after dopamine agents were initiated, and there were no cases of dopaminergic agents inducing novel NE or SRED.

CONCLUSION

NE is common in RLS and not due to frequent nocturnal awakenings or dopaminergic agents. Amnestic SRED occurs predominantly in the setting of RLS mistreatment with sedating agents. In light of previous reports, these findings suggest that nocturnal eating is a non-motor manifestation of RLS with several clinical implications discussed here.