More Delusions May Be Observed in Low-Proficient Multilingual Alzheimer’s Disease Patients

Background

Language impairment and behavioral symptoms are both common phenomena in dementia patients. In this study, we investigated the behavioral symptoms in dementia patients with different language backgrounds. Through this, we aimed to propose a possible connection between language and delusion.

Methods

We recruited 21 patients with Alzheimer’s disease (AD), according to the DSM-IV and NINCDS-ADRDA criteria, from the memory clinic of the Cardinal Tien Hospital in Taipei, Taiwan. They were classified into two groups: 11 multilinguals who could speak Japanese, Taiwanese and Mandarin Chinese, and 10 bilinguals who only spoke Taiwanese and Mandarin Chinese. There were no differences between age, education, disease duration, disease severity, environment and medical care between these two groups. Comprehensive neuropsychological examinations, including Clinical Dementia Rating (CDR), Mini-Mental Status Examination (MMSE), Cognitive Abilities Screening Instrument (CASI), Verbal fluency, Chinese version of the Boston naming test (BNT) and the Behavioral Pathology in Alzheimer’s Disease Rating Scale (BEHAVE-AD), were administered.

Results

The multilingual group showed worse results on the Boston naming test. Other neuropsychological tests, including the MMSE, CASI and Verbal fluency, were not significantly different. More delusions were noted in the multilingual group. Three pairs of subjects were identified for further examination of their differences. These three cases presented the typical scenario of how language misunderstanding may cause delusions in multilingual dementia patients. Consequently, more emotion and distorted ideas may be induced in the multilinguals compared with the MMSE-matched controls.

Conclusion

Inappropriate mixing of language or conflict between cognition and emotion may cause more delusions in these multilingual patients. This reminds us that delusion is not a pure biological outcome of brain degeneration. Although the cognitive performance was not significantly different between our groups, language may still affect their delusion.     

Parkinson’s Disease in Saudi Patients: A Genetic Study

Parkinson’s disease (PD) is one of the major causes of parkinsonism syndrome. Its characteristic motor symptoms are attributable to dopaminergic neurons loss in the midbrain. Genetic advances have highlighted underlying molecular mechanisms and provided clues to potential therapies. However, most of the studies focusing on the genetic component of PD have been performed on American, European and Asian populations, whereas Arab populations (excluding North African Arabs), particularly Saudis remain to be explored. Here we investigated the genetic causes of PD in Saudis by recruiting 98 PD-cases (sporadic and familial) and screening them for potential pathogenic mutations in PD-established genes; SNCA, PARKIN, PINK1, PARK7/DJ1, LRRK2 and other PD-associated genes using direct sequencing. To our surprise, the screening revealed only three pathogenic point mutations; two in PINK1 and one in PARKIN. In addition to mutational analysis, CNV and cDNA analysis was performed on a subset of patients. Exon/intron dosage alterations in PARKIN were detected and confirmed in 2 cases. Our study suggests that mutations in the ORF of the screened genes are not a common cause of PD in Saudi population; however, these findings by no means exclude the possibility that other genetic events such as gene expression/dosage alteration may be more common nor does it eliminate the possibility of the involvement of novel genes.     

Imaging Striatal Microglial Activation in Patients with Parkinson’s Disease

This study investigated whether the second-generation translocator protein 18kDa (TSPO) radioligand, [¹⁸F]-FEPPA, could be used in neurodegenerative parkinsonian disorders as a biomarker for detecting neuroinflammation in the striatum. Neuroinflammation has been implicated as a potential mechanism for the progression of Parkinson’s disease (PD). Positron Emission Tomography (PET) radioligand targeting for TSPO allows for the quantification of neuroinflammation in vivo. Based on genotype of the rs6791 polymorphism in the TSPO gene, 16 mixed-affinity binders (MABs) (8 PD and age-matched 8 healthy controls (HCs)), 16 high-affinity binders (HABs) (8 PD and age-matched 8 HCs) and 4 low-affinity binders (LABs) (3 PD and 1 HCs) were identified. Total distribution volume (V_T) values in the striatum were derived from a two-tissue compartment model with arterial plasma as an input function. There was a significant main effect of genotype on [¹⁸F]-FEPPA V_T values in the caudate nucleus (p = 0.001) and putamen (p < 0.001), but no main effect of disease or disease x genotype interaction in either ROI. In the HAB group, the percentage difference between PD and HC was 16% in both caudate nucleus and putamen; in the MAB group, it was -8% and 3%, respectively. While this PET study showed no evidence of increased striatal TSPO expression in PD patients, the current findings provide some insights on the possible interactions between rs6791 polymorphism and neuroinflammation in PD.     

Interleukin-6 Serum Levels in Patients with Parkinson’s Disease

Several lines of evidence suggest that neuroimmune mechanisms may be involved in the neurodegenerative process of Parkinson’s disease (PD). Interleukin-6 (IL-6) is increased in the nigrostriatal region and in the cerebrospinal fluid of patients with PD. IL-6 serum level was evaluated in PD patients. The effects of levodopa treatment and disease severity on IL-6 were also studied. The IL-6 levels were similar between PD patients (treated and not treated) and controls. However, there was a negative correlation of IL-6 levels and the activities of daily living scale (P < 0.05), indicating that patients with more severe disease have higher levels of this cytokine. No correlation involving levodopa treatment and IL-6 serum level was found. The results suggest that only marginal effects of IL-6 occur on the peripheral immune system, and that the role of IL-6 and others neuroimmune factors needs to be well elucidated on PD.     

Cellular Senescence Is Induced by the Environmental Neurotoxin Paraquat and Contributes to Neuropathology Linked to Parkinson’s Disease

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Mechanisms of Glucocerebrosidase Dysfunction in Parkinson’s Disease

Beta-glucocerebrosidase is a lysosomal hydrolase, encoded by GBA1 that represents the most common risk gene associated with Parkinson’s disease (PD) and Lewy Body Dementia. Glucocerebrosidase dysfunction has been also observed in the absence of GBA1 mutations across different genetic and sporadic forms of PD and related disorders, suggesting a broader role of glucocerebrosidase in neurodegeneration. In this review, we highlight recent advances in mechanistic characterization of glucocerebrosidase function as the foundation for development of novel therapeutics targeting glucocerebrosidase in PD and related disorders.     

Mitochondrial Sirtuins in Parkinson’s Disease

Neurochemical Research - Parkinson’s disease (PD), the main risk factor for which is age, is one of the most common neurodegenerative diseases and imposes a substantial burden on affected...     

Carpal Tunnel Syndrome in Patients with Tremor Dominant Parkinson’s Disease

Background

Unilateral hand tremor is one of the cardinal symptoms of Parkinson’s disease. Additionally, mechanical traumatic hand movement is one of the risk factors for carpal tunnel syndrome. Our objective in this study was to examine whether repetitive mechanical movement may be related to the development of carpal tunnel syndrome in Parkinson’s disease with unilateral hand tremor using neurophysiological methods.

Methods

The study participants included 33 de novo Parkinson’s disease patients with unilateral hand tremor, and we compared the tremor hand and non-tremor hand within the same patients.

Results

Seven (21.2%) of the 33 patients had carpal tunnel syndrome. All of carpal tunnel syndrome patients showed neurophysiological abnormalities in both the hand without tremor and the hand with tremor. In addition, in patients without carpal tunnel syndrome, the sensory nerve action potential was lower in the hand without tremor than in the hand with tremor, although there were no significant differences.

Conclusions

We concluded that hand tremor in de novo Parkinson’s disease patients was not directly related to the development of carpal tunnel syndrome. In contrast, more frequent use of hand without tremor may induce mechanical loading and may be associated with CTS in the hand without tremor. Early diagnosis of Parkinson’s disease and proper education in hand use may be essential for preventing carpal tunnel syndrome in Parkinson’s disease tremor patients.     

Challenging Postural Tasks Increase Asymmetry in Patients with Parkinson’s Disease

The unilateral predominance of Parkinson’s disease (PD) symptoms suggests that balance control could be asymmetrical during static tasks. Although studies have shown that balance control asymmetries exist in patients with PD, these analyses were performed using only simple bipedal standing tasks. Challenging postural tasks, such as unipedal or tandem standing, could exacerbate balance control asymmetries. To address this, we studied the impact of challenging standing tasks on postural control asymmetry in patients with PD. Twenty patients with PD and twenty neurologically healthy individuals (control group) participated in this study. Participants performed three 30s trials for each postural task: bipedal, tandem adapted and unipedal standing. The center of pressure parameter was calculated for both limbs in each of these conditions, and the asymmetry between limbs was assessed using the symmetric index. A significant effect of condition was observed, with unipedal standing and tandem standing showing greater asymmetry than bipedal standing for the mediolateral root mean square (RMS) and area of sway parameters, respectively. In addition, a group*condition interaction indicated that, only for patients with PD, the unipedal condition showed greater asymmetry in the mediolateral RMS and area of sway than the bipedal condition and the tandem condition showed greater asymmetry in the area of sway than the bipedal condition. Patients with PD exhibited greater asymmetry while performing tasks requiring postural control when compared to neurologically healthy individuals, especially for challenging tasks such as tandem and unipedal standing.     

Plasma Exosomes in Inherited Forms of Parkinson’s Disease

Molecular Biology - Parkinson’s disease (PD) is the second most common neurodegenerative disorder. Alpha-synuclein misfolding and aggregation resulting in neurototoxicity is a hallmark of PD....     

Upregulation of GPR109A in Parkinson’s Disease

Background

Anecdotal animal and human studies have implicated the symptomatic and neuroprotective roles of niacin in Parkinson’s disease (PD). Niacin has a high affinity for GPR109A, an anti-inflammatory receptor. Niacin is also thought to be involved in the regulation of circadian rhythm. Here we evaluated the relationships among the receptor, niacin levels and EEG night-sleep in individuals with PD.

Methods and Findings

GPR109A expression (blood and brain), niacin index (NAD-NADP ratio) and cytokine markers (blood) were analyzed. Measures of night-sleep function (EEG) and perceived sleep quality (questionnaire) were assessed. We observed significant up-regulation of GPR109A expression in the blood as well as in the substantia nigra (SN) in the PD group compared to age-matched controls. Confocal microscopy demonstrated co-localization of GPR109A staining with microglia in PD SN. Pro and anti-inflammatory cytokines did not show significant differences between the groups; however IL1-β, IL-4 and IL-7 showed an upward trend in PD. Time to sleep (sleep latency), EEG REM and sleep efficiency were different between PD and age-matched controls. Niacin levels were lower in PD and were associated with increased frequency of experiencing body pain and decreased duration of deep sleep.

Conclusions

The findings of associations among the GPR109A receptor, niacin levels and night-sleep function in individuals with PD are novel. Further studies are needed to understand the pathophysiological mechanisms of action of niacin, GPR109A expression and their associations with night-sleep function. It would be also crucial to study GPR109A expression in neurons, astrocytes, and microglia in PD. A clinical trial to determine the symptomatic and/or neuroprotective effect of niacin supplementation is warranted.     

Naturally Occurring Alpha-Synuclein Autoantibodies in Parkinson’s Disease: Sources of (Error) Variance in Biomarker Assays

Alpha-synuclein (α-Syn) plays a pivotal role in the pathophysiology of Parkinson’s disease (PD), which can partly be modulated by innate and adaptive immune functions, and vice versa. Here, naturally occurring α-Syn autoantibodies (α-Syn-nAbs) may be effective against α-Syn pathoetiology and may serve as a PD biomarker. However, serum and cerebrospinal fluid α-Syn-nAbs levels still lack consistent evidence as required for a reliable PD biomarker. Serum and cerebrospinal fluid α-Syn-nAbs levels of 66 PD patients and 69 healthy controls were assessed using a validated ELISA assay. Moreover, potential sources of error variance including unspecific ELISA background signals, free serum hemoglobin concentrations, α-Syn plate coating procedures, and differences in α-Syn-nAbs standards, were investigated. PD patients and controls did not differ in serum (p = .49) nor cerebrospinal fluid (p = .29) α-Syn-nAbs levels. Interestingly, free serum hemoglobin concentrations were negatively correlated with α-Syn-nAbs levels in controls (Spearman  = −.41, p<.001), but not in PD patients ( = .16, p = .21). ELISA α-Syn plate coating procedures impacted inter-assay variability (same day coating: 8–16%; coating on different days: 16–58%). α-Syn-nAbs standards from different purification batches differed regarding optical density measured in ELISAs suggesting differences in α-Syn affinity. While α-Syn-nAbs levels may represent a potential PD biomarker, several methodological issues have to be considered to increase reproducibility of α-Syn-nAbs findings. Further studies using standardized protocols minimizing sources of error variance may be necessary to establish a reliable PD α-Syn-nAbs biomarker.     

Increased Levels of Antigen-Bound β-Amyloid Autoantibodies in Serum and Cerebrospinal Fluid of Alzheimer’s Disease Patients

Recent studies have suggested a protective role of physiological β-amyloid autoantibodies (Aβ-autoantibodies) in Alzheimer’s disease (AD). However, the determination of both free and dissociated Aβ-autoantibodies in serum hitherto has yielded inconsistent results regarding their function and possible biomarker value. Here we report the application of a new sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of antigen-bound Aβ-autoantibodies (intact Aβ-IgG immune complexes) in serum and cerebrospinal fluid (CSF) of a total number of 112 AD patients and age- and gender-matched control subjects. Both serum and CSF levels of Aβ-IgG immune complexes were found to be significantly higher in AD patients compared to control subjects. Moreover, the levels of Aβ-IgG complexes were negatively correlated with the cognitive status across the groups, increasing with declining cognitive test performance of the subjects. Our results suggest a contribution of IgG-type autoantibodies to Aβ clearance in vivo and an increased immune response in AD, which may be associated with deficient Aβ-IgG removal. These findings may contribute to elucidating the role of Aβ-autoantibodies in AD pathophysiology and their potential application in AD diagnosis.     

Relationship between Eating Disturbance and Dementia Severity in Patients with Alzheimer’s Disease

Background

Eating is one of the most important daily activities in managing patients with dementia. Although various eating disturbance occur as dementia progresses, to our knowledge, most of the studies focused on a part of eating disturbance such as swallowing and appetite. There have been few comprehensive studies including eating habits and food preference in patients with Alzheimer’s disease (AD). The aims of this study were to investigate almost all eating disturbance and to examine the relationship of eating disturbance to dementia stage in AD.

Methods

A total of 220 patients with AD and 30 normal elderly (NE) subjects were recruited. Eating disturbance was assessed by a comprehensive questionnaire that had been previously validated. Potential relationships between the characteristics of eating disturbance and dementia stage as classified by the Clinical Dementia Rating (CDR) were assessed.

Results

Overall, 81.4% of patients with AD showed some eating and swallowing disturbance, whereas only 26.7% of the NE subjects had such a disturbance. Even in an early stage, patients with AD had many types of eating disturbance; “Appetite change” was shown in nearly half of the mild AD patients (49.5%). In the moderate stage, the scores of “change of eating habits and food preference” were highest, and in the severe stage “swallowing disturbance” became critical.

Conclusion

In AD, the relationship of dementia stage to eating disturbance differs according to the type of eating disturbance. The relationships between various eating disturbance and the severity of dementia should be considered.     

Molecular Effects of L-dopa Therapy in Parkinson’s Disease

Parkinson’s disease (PD) is one of the most common neurological diseases in elderly people. The mean age of onset is 55 years of age, and the risk for developing PD increases 5-fold by the age of 70. In PD, there is impairment in both motor and nonmotor (NMS) functions. The strategy of PD motor dysfunction treatment is simple and generally based on the enhancement of dopaminergic transmission by means of the L-dihydroxyphenylalanine (L-dopa) and dopamine (DA) agonists. L-dopa was discovered in the early -60''s of the last century by Hornykiewicz and used for the treatment of patients with PD. L-dopa treatment in PD is related to decreased levels of the neurotransmitter (DA) in striatum and ab-sence of DA transporters on the nerve terminals in the brain. L-dopa may also indirectly stimulate the receptors of the D1 and D2 families. Administration of L-dopa to PD patients, especially long-time therapy, may cause side effects in the form of increased toxicity and inflammatory response, as well as disturbances in biothiols metabolism. Therefore, in PD pa-tients treated with L-dopa, monitoring of oxidative stress markers (8-oxo-2’-deoxyguanosine, apoptotic proteins) and in-flammatory factors (high-sensitivity C-reactive protein, soluble intracellular adhesion molecule), as well as biothiol com-pounds (homocysteine, cysteine, glutathione) is recommended. Administration of vitamins B6, B12, and folates along with an effective therapy with antioxidants and/or anti-inflammatory drugs at an early stage of PD might contribute to improvement in the quality of the life of patients with PD and to slowing down or stopping the progression of the disease.     

Long Non-coding RNAs in Parkinson’s Disease

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder and is associated with a range of motor and non-motor clinical symptoms. The underlying molecular pathogenesis of PD involves a variety of pathways and mechanisms, including α-synuclein proteostasis, mitochondrial dysfunction, oxidative stress, autophagy and apoptosis, neuroinflammation, and epigenetic regulation. Long non-coding RNAs (lncRNAs) are involved in the regulation of multiple pathological processes of PD. In this review, we provide an overview of large-scale studies on lncRNA expression profiling in PD patients and models, as well as highlight the impacts of lncRNAs on the pathogenesis of PD, which could provide basic information regarding the putative lncRNA-based biomarkers and therapeutic targets for the early diagnosis and treatment strategies for PD.

     

Synaptic Protein Alterations in Parkinson’s Disease

Alterations occur within distal neuronal compartments, including axons and synapses, during the course of neurodegenerative diseases such as Parkinson’s disease (PD). These changes could hold important implications for the functioning of neural networks, especially since research studies have shown a loss of dendritic spines locating to medium spiny projection neurons and impaired axonal transport in PD-affected brains. However, despite ever-increasing awareness of the vulnerability of synapses and axons, inadequate understanding of the independent mechanisms regulating non-somatic neurodegeneration prevails. This has resulted in limited therapeutic strategies capable of targeting these distinct cellular compartments. Deregulated protein synthesis, folding and degrading proteins, and protein quality-control systems have repeatedly been linked with morphological and functional alterations of synapses in the PD-affected brains. Here, we review current understanding concerning the proteins involved in structural and functional changes that affect synaptic contact-points in PD. The collection of studies discussed emphasizes the need for developing therapeutics aimed at deregulated protein synthesis and degradation pathways operating at axonal and dendritic synapses for preserving “normal” circuitry and function, for as long as possible.