Swallowing disturbances in Parkinson's disease: a multivariate analysis of contributing factors

Critical Dysphagia is Common in Parkinson Disease and Occurs Even in Early Stages: A Prospective Cohort Study

To assess the prevalence of dysphagia and its typical findings in unselected "real-world" Parkinson patients using an objective gold-standard method. This was a prospective, controlled, cross-sectional study conducted in 119 consecutive Parkinson patients of all stages independent of subjective dysphagia. Patients and 32 controls were clinically and endoscopically examined by flexible endoscopic evaluation of swallowing (FEES) to evaluate the deglutition with regard to three consistencies (water, biscuit, and bread). Typical findings of dysphagia like penetration and aspiration, residues, and leakage were assessed. Dysphagia was common in Parkinson patients and occurred in all, even early, disease stages. Only 5% (6/119) of patients showed a completely unremarkable deglutition. Aspiration was seen in 25% (30/119) of patients and always related to water. Residues occurred in 93% (111/119), most commonly for bread. Leakage was much less frequent and was found in only 3-18%, depending on consistency. In a significant fraction of patients, objective dysphagia was not subjectively perceived. A total of 16% of asymptomatic patients suffered from critical aspiration. Significant swallowing deficiencies already occurred in early disease. Aspiration was found in 4 of 20 (20%) patients with disease duration of less than 2 years. Seven of 57 patients (12%) with Hoehn and Yahr stage 2 suffered from severe aspiration. Given the high frequency of critical aspiration in Parkinson disease, these patients should be evaluated early for dysphagia to avoid complications and recommend an adequate therapy. FEES is a simple, cost efficient, minimally invasive method that is ideally suited for this purpose.

Neuropathology of Nonmotor Symptoms of Parkinson's Disease

Parkinson's disease (PD), a multiorgan neurodegenerative disorder associated with α-synuclein deposits throughout the nervous system and many organs, is clinically characterized by motor and nonmotor features, many of the latter antedating motor dysfunctions by 20 or more years. The causes of the nonmotor manifestations such as olfactory, autonomic, sensory, neuropsychiatric, visuospatial, sleep, and other disorders are unlikely to be related to single lesions. They are mediated by the involvement of both dopaminergic and nondopaminergic systems, and diverse structures outside the nigrostriatal system that is mainly responsible for the motor features of PD. The nonmotor alterations appear in early/prodromal stages of the disease and its further progression, suggesting a topographical and chronological spread of the lesions. This lends further support for the notion that PD is a multiorgan proteinopathy, although the exact relationship between presymptomatic and later developing nonmotor features of PD and neuropathology awaits further elucidation.

Dietary habits in Parkinson's disease: Adherence to Mediterranean diet

INTRODUCTION

Our objective is to describe the dietary habits, food preferences and adherence to Mediterranean diet (MeDi) of a large sample of Italian Parkinson's Disease (PD) patients compared to a group of controls.

METHODS

Dietary habits of 600 PD patients from throughout Italy and 600 controls matched by gender, age, education, physical activity level and geographical residence, were collected using the ON-GP Food Frequency Questionnaire. Then, we compared patients by disease duration and the presence of swallowing disturbances.

RESULTS

Overall, adherence of PD patients (males, 53.8%; mean disease duration, 9.2 ± 7.0 years) to MeDi was similar to controls (score, 4.8 ± 1.7 vs. 4.9 ± 1.6; P = 0.294). Patients consumed less alcohol and fish and drank significantly less water, coffee, and milk which resulted also in lower total fluids intake. On the contrary, they ate more fruit, cooked vegetables, cereals and baked items, more dressings and more sweets in general. Disease duration was associated with increased intake of several food groups but it was not associated with changes in MeDi score (P = 0.721). Patients with swallowing disturbances (n = 72) preferred softer and more viscous food but preferences did not result in differences in dietary pattern. However, patients with dysphagia drank less fluids (P = 0.043).

DISCUSSION

PD patients presented different dietary habits and food preferences compared to the general population and adherence to MeDi was not associated with disease duration. Self-reported dysphagia was associated with reduced intake of fluids. These aspects may be amenable to change in order to improve the management of nutritional issues in this patient population.

Maladie de Parkinson et syndromes parkinsoniens : les signes moteurs

Parkinsonian syndrome is the clinical expression of a lesion within the nigro-striatal dopaminergic pathway. Akinesia is the main manifestation of parkinsonism. The clinical analysis of motor symptoms may guide clinical diagnosis. Parkinson's disease is characterized by a pure asymmetric parkinsonian syndrome, responsive to dopaminergic treatment. The evolution of Parkinson's disease is characterized by the occurrence of motor complications (dyskinesia and fluctuations). Gait disturbances (postural instability and freezing) are late in Parkinson's disease. When early (within the first three years), they point to atypical parkinsonian syndrome.

Cognitive and Motor Aspects of Parkinson's Disease Associated with Dysphagia

BACKGROUND

Dysphagia is a common symptom and an important prognostic factor in Parkinson's disease (PD). Although cognitive and motor dysfunctions may contribute to dysphagia in patients with PD, any specific association between such problems and swallowing functions is unclear. Here, we examined the potential relationship between cognitive/motor components and swallowing functions in PD. We evaluated the contributions of cognition and motor function to the components of swallowing via video fluoroscopic swallowing (VFS) experiments.

METHODS

We prospectively enrolled 56 patients without dementia having PD. Parkinson's disease severity was assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). All participants received neuropsychological tests covering general mental status, visuospatial function, attention, language, learning and memory, and frontal executive function. The well-validated "modified barium swallow impairment profile" scoring system was applied during VFS studies to quantify swallowing impairments. Finally, correlations between neuropsychological or motor functions and impairment in swallowing components were calculated.

RESULTS

The most significant correlations were found between the frontal/executive or learning/memory domains and the oral phase of swallowing, though a minor component of the pharyngeal phase correlated with frontal function as well. Bradykinesia and the UPDRS total score were associated with both the pharyngeal and oral phases.

CONCLUSIONS

Our findings suggest that cognitive dysfunctions are associated with the oral phase of swallowing in patients with early stage PD while the severity of motor symptoms may be associated with overall swallowing function.

Axonopathy in the Central Nervous System Is the Hallmark of Mice with a Novel Intragenic Null Mutation of Dystonin

Dystonia musculorum is a neurodegenerative disorder caused by a mutation in the dystonin gene. It has been described in mice and humans where it is called hereditary sensory autonomic neuropathy. Mutated mice show severe movement disorders and die at the age of 3-4 weeks. This study describes the discovery and molecular, clinical, as well as pathological characterization of a new spontaneously occurring mutation in the dystonin gene in C57BL/6N mice. The mutation represents a 40-kb intragenic deletion allele of the dystonin gene on chromosome 1 with exactly defined deletion borders. It was demonstrated by Western blot, mass spectrometry, and immunohistology that mice with a homozygous mutation were entirely devoid of the dystonin protein. Pathomorphological lesions were restricted to the brain stem and spinal cord and consisted of swollen, argyrophilic axons and dilated myelin sheaths in the white matter and, less frequently, total chromatolysis of neurons in the gray matter. Axonal damage was detected by amyloid precursor protein and nonphosphorylated neurofilament immunohistology. Axonopathy in the central nervous system (CNS) represents the hallmark of this disease. Mice with the dystonin mutation also showed suppurative inflammation in the respiratory tract, presumably due to brain stem lesion-associated food aspiration, whereas skeletal muscles showed no pathomorphological changes. This study describes a novel mutation in the dystonin gene in mice leading to axonopathy in the CNS. In further studies, this model may provide new insights into the pathogenesis of neurodegenerative diseases and may elucidate the complex interactions of dystonin with various other cellular proteins especially in the CNS.

Analysis of resources assisting in coping with swallowing difficulties for patients with Parkinson's disease: a cross-sectional study

BACKGROUND

Malnutrition induced by swallowing difficulties (SD) impairs the quality of life and gives rise to SD-related costs in Parkinson's disease (PD) patients. With results of a swallowing difficulty questionnaire and data of resources specifically obtained such as SD-related costs, caregivers, and dietary therapies, this study is to suggest statistically supported ideas for improvements in arrangements for how participants cope with SD and maintain general well-being.

METHODS

We interviewed 237 PD patients. The SD-related costs involved those incurred by the provision of dietary modifications, care oriented foods, alternatives, and supplements. Dietary therapies included rice porridge and commercially available care foods. The relationships between BMI (body mass index) and the severity of SD assumed in this paper as indicators for general well-being and as resources for coping with SD for PD patients were statistically analyzed.

RESULTS

A lower BMI was found in participants eating porridge consistency rice (p = 0.003) and eating porridge rice is significantly related to the severity of SD (p < 0.0001) and PD (p = 0.002). The severity of SD increased with age and PD duration (p = 0.035, p = 0.0005). Outlays for dietary modifications are the lowest reported here (p < 0.004) but the number of participants using dietary modifications is the largest among the SD-related items (n = 58). Eating care foods were reported for 11 older participants (p < 0.0001), most female (10/11). No lower BMI was found in participants eating care foods when compared with participants eating ordinary foods. Dietary modifications were performed by caregivers (OR: 6.8, CI: 3.1-15.2, p < 0.0001) and were related to the presence of children (OR: 3.4, CI: 1.2-11.4. p = 0.024). Older participants commonly live with spouses and children.

CONCLUSIONS

Severe SD is associated with higher costs of coping with SD. A lower BMI is associated with modified foods, mostly eaten to cope with SD. Presence of caregivers and other persons residing with the participants here are related to dietary modifications but not to care food-related costs. Care foods may be effective in preventing malnutrition although the number who are able to cover the added expenses is limited because of the higher prices and shortage of information on the usefulness of care foods.

Gut dysfunction in Parkinson's disease

Early involvement of gut is observed in Parkinson’s disease (PD) and symptoms such as constipation may precede motor symptoms. α-Synuclein pathology is extensively evident in the gut and appears to follow a rostrocaudal gradient. The gut may act as the starting point of PD pathology with spread toward the central nervous system. This spread of the synuclein pathology raises the possibility of prion-like propagation in PD pathogenesis. Recently, the role of gut microbiota in PD pathogenesis has received attention and some phenotypic correlation has also been shown. The extensive involvement of the gut in PD even in its early stages has led to the evaluation of enteric α-synuclein as a possible biomarker of early PD. The clinical manifestations of gastrointestinal dysfunction in PD include malnutrition, oral and dental disorders, sialorrhea, dysphagia, gastroparesis, constipation, and defecatory dysfunction. These conditions are quite distressing for the patients and require relevant investigations and adequate management. Treatment usually involves both pharmacological and non-pharmacological measures. One important aspect of gut dysfunction is its contribution to the clinical fluctuations in PD. Dysphagia and gastroparesis lead to inadequate absorption of oral anti-PD medications. These lead to response fluctuations, particularly delayed-on and no-on, and there is significant relationship between levodopa pharmacokinetics and gastric emptying in patients with PD. Therefore, in such cases, alternative routes of administration or drug delivery systems may be required.

Analysis of Mitochondrial haemoglobin in Parkinson's disease brain

Mitochondrial dysfunction is an early feature of neurodegeneration. We have shown there are mitochondrial haemoglobin changes with age and neurodegeneration. We hypothesised that altered physiological processes are associated with recruitment and localisation of haemoglobin to these organelles. To confirm a dynamic localisation of haemoglobin we exposed Drosophila melanogaster to cyclical hypoxia with recovery. With a single cycle of hypoxia and recovery we found a relative accumulation of haemoglobin in the mitochondria compared with the cytosol. An additional cycle of hypoxia and recovery led to a significant increase of mitochondrial haemoglobin (p<0.05). We quantified ratios of human mitochondrial haemoglobin in 30 Parkinson's and matched control human post-mortem brains. Relative mitochondrial/cytosolic quantities of haemoglobin were obtained for the cortical region, substantia nigra and cerebellum. In age matched post-mortem brain mitochondrial haemoglobin ratios change, decreasing with disease duration in female cerebellum samples (n=7). The change is less discernible in male cerebellum (n=18). In cerebellar mitochondria, haemoglobin localisation in males with long disease duration shifts from the intermembrane space to the outer membrane of the organelle. These new data illustrate dynamic localisation of mitochondrial haemoglobin within the cell. Mitochondrial haemoglobin should be considered in the context of gender differences characterised in Parkinson's disease. It has been postulated that cerebellar circuitry may be activated to play a protective role in individuals with Parkinson's. The changing localisation of intracellular haemoglobin in response to hypoxia presents a novel pathway to delineate the role of the cerebellum in Parkinson's disease.

Assessment of Oropharyngeal Dysphagia in Patients With Parkinson Disease: Use of Ultrasonography

Objective

To compare tongue thickness, the shortest hyoid-thyroid approximation (distance between the hyoid bone and thyroid cartilage), and the time interval between the initiation of tongue movement and the time of the shortest hyoid-thyroid approximation, by using ultrasonography in healthy controls and patients with Parkinson disease (PD).

Methods

Healthy controls and PD patients with dysphagia were compared. Ultrasonography was performed 3 times for the evaluation of tongue thickness, the shortest hyoid-thyroid approximation, and the time between the initiation of tongue movement and the shortest hyoid-thyroid approximation.

Results

A total of 24 healthy controls and 24 PD patients with dysphagia were enrolled. No significant differences were demonstrated between the two groups for the shortest hyoid-thyroid approximation (controls, 1.19±0.34 cm; PD patients, 1.37±0.5 cm; p=0.15) and tongue thickness (controls, 4.42±0.46 cm; PD patients, 4.27±0.51 cm; p=0.3). In contrast, the time to the shortest hyoid-thyroid approximation was significantly different between the two groups (controls, 1.53±0.87 ms; PD patients, 2.4±1.4 ms, p=0.048).

Conclusion

Ultrasonography can be useful in evaluating dysphagia in patients with PD by direct visualization and measurement of the hyoid bone. Moreover, ultrasonography might contribute to a greater understanding of the pathophysiology of dysphagia in PD.

Measurement of Voluntary Cough Production and Airway Protection in Parkinson Disease

OBJECTIVE

To examine relations between peak expiratory (cough) airflow rate and swallowing symptom severity in participants with Parkinson disease (PD).

DESIGN

Cross-sectional study.

SETTING

Outpatient radiology clinic at an acute care hospital.

PARTICIPANTS

Men and women with PD (N=68).

INTERVENTIONS

Participants were cued to cough into an analog peak flow meter then swallowed three 20-mL thin liquid barium boluses. Analyses were directed at detecting potential relations among disease severity, swallowing symptom severity, and peak expiratory (cough) airflow rate.

MAIN OUTCOME MEASURES

Peak expiratory (cough) airflow rate and swallow symptom severity.

RESULTS

Peak expiratory (cough) airflow rate varied significantly across swallowing severity classifications. Participants with more severe disease displayed a significant, linear decrease in peak expiratory (cough) airflow rate than those participants with earlier stage, less severe disease. Swallowing symptom severity varied significantly across groups when comparing participants with less severe PD with those with more severe PD. Participants with early stage PD demonstrated little to no swallowing symptoms and had the highest measures of peak expiratory (cough) airflow rate. In contrast, participants with the most severe swallowing symptoms also displayed the lowest measures of peak expiratory (cough) airflow rate.

CONCLUSIONS

Relations existed among PD severity, swallowing symptom severity, and peak expiratory (cough) airflow rate in participants with PD. Peak expiratory (cough) airflow rate may eventually stand as a noninvasive predictor of aspiration risk in those with PD, particularly those with later stage disease. Inclusion of peak expiratory (cough) airflow rates into existing clinical swallowing assessments may increase the sensitivity and predictive validity of these assessments.

Oropharyngeal dysphagia in older persons - from pathophysiology to adequate intervention: a review and summary of an international expert meeting

Oropharyngeal dysphagia (OD) is a highly prevalent and growing condition in the older population. Although OD may cause very severe complications, it is often not detected, explored, and treated. Older patients are frequently unaware of their swallowing dysfunction which is one of the reasons why the consequences of OD, ie, aspiration, dehydration, and malnutrition, are regularly not attributed to dysphagia. Older patients are particularly vulnerable to dysphagia because multiple age-related changes increase the risk of dysphagia. Physicians in charge of older patients should be aware that malnutrition, dehydration, and pneumonia are frequently caused by (unrecognized) dysphagia. The diagnosis is particularly difficult in the case of silent aspiration. In addition to numerous screening tools, videofluoroscopy was the traditional gold standard of diagnosing OD. Recently, the fiberoptic endoscopic evaluation of swallowing is increasingly utilized because it has several advantages. Besides making a diagnosis, fiberoptic endoscopic evaluation of swallowing is applied to evaluate the effectiveness of therapeutic maneuvers and texture modification of food and liquids. In addition to swallowing training and nutritional interventions, newer rehabilitation approaches of stimulation techniques are showing promise and may significantly impact future treatment strategies.

Parkinson Disease-Mediated Gastrointestinal Disorders and Rational for Combinatorial Therapies

A gradual loss of dopamine-producing nerve cells gives rise to a common neurodegenerative Parkinson’s disease (PD). This disease causes a neurotransmitter imbalance in the brain and initiates a cascade of complications in the rest of the body that appears as distressing symptoms which include gait problems, tremor, gastrointestinal (GI) disorders and cognitive decline. To aid dopamine deficiency, treatment in PD patients includes oral medications, in addition to other methods such as deep brain stimulation and surgical lesioning. Scientists are extensively studying molecular and signaling mechanisms, particularly those involving phenotypic transcription factors and their co-regulatory proteins that are associated with neuronal stem cell (SC) fate determination, maintenance and disease state, and their role in the pathogenesis of PD. Advancement in scientific research and “personalized medicine” to augment current therapeutic intervention and minimize the side effects of chemotherapy may lead to the development of more effective therapeutic strategies in the near future. This review focuses on PD and associated GI complications and summarizes the current therapeutic modalities that include stem cell studies and combinatorial drug treatment.

Dysphagia in Parkinson's Disease

More than 80 % of patients with Parkinson's disease (PD) develop dysphagia during the course of their disease. Swallowing impairment reduces quality of life, complicates medication intake and leads to malnutrition and aspiration pneumonia, which is a major cause of death in PD. Although the underlying pathophysiology is poorly understood, it has been shown that dopaminergic and non-dopaminergic mechanisms are involved in the development of dysphagia in PD. Clinical assessment of dysphagia in PD patients is challenging and often delivers unreliable results. A modified water test assessing maximum swallowing volume is recommended to uncover oropharyngeal dysphagia in PD. PD-specific questionnaires may also be useful to identify patients at risk for swallowing impairment. Fiberoptic endoscopic evaluation of swallowing and videofluoroscopic swallowing study are both considered to be the gold standard for evaluation of PD-related dysphagia. In addition, high-resolution manometry may be a helpful tool. These instrumental methods allow a reliable detection of aspiration events. Furthermore, typical patterns of impairment during the oral, pharyngeal and/or esophageal swallowing phase of PD patients can be identified. Therapy of dysphagia in PD consists of pharmacological interventions and swallowing treatment by speech and language therapists (SLTs). Fluctuating dysphagia with deterioration during the off-state should be treated by optimizing dopaminergic medication. The methods used during swallowing treatment by SLTs shall be selected according to the individual dysphagia pattern of each PD patient. A promising novel method is an intensive training of expiratory muscle strength. Deep brain stimulation does not seem to have a clinical relevant effect on swallowing function in PD. The goal of this review is giving an overview on current stages of epidemiology, pathophysiology, diagnosis, and treatment of PD-associated dysphagia, which might be helpful for neurologists, speech-language therapists, and other clinicians in their daily work with PD patients and associated swallowing difficulties. Furthermore areas with an urgent need for future clinical research are identified.

Optimising medication for Parkinson's disease patients with dysphagia

In addition to movement disorders, Parkinson's disease (PD) is associated with several nonmotor symptoms, including dysphagia (swallowing difficulties). Dysphagia can make the consumption of solid medicines difficult, which potentially contributes to the poor adherence that is common among people with PD. However, patients may be reluctant to admit that they experience dysphagia. Community nurses should actively enquire into swallowing difficulties among all patients, not only those with PD, and should work with pharmacists and other members of the multidisciplinary team to help optimise medication management to help improve adherence.

Swallowing disturbances in the corticobasal syndrome

OBJECTIVES

To determine the characteristics of swallowing and speech disturbances in patients with corticobasal syndrome (CBS) compared to healthy controls, and whether a subjective swallowing questionnaire, the NIH-Speech Pathology swallowing questionnaire (NIH-SQ), can predict swallowing impairment.

METHODS

Twenty-four consecutive CBS patients underwent a swallowing assessment comprised of the NIH-SQ, ultrasound swallow study (US) and modified barium swallow (MBS) study. Healthy controls (n = 28) completed the NIH-SQ and the US.

RESULTS

Ninety-six percent of the patients with CBS reported at least one complaint in the NIH-SQ, 59% had abnormal dry swallow duration and 10% abnormal wet swallow duration. Twenty-three patients with CBS had some abnormality on the MBS. The MBS category "piecemeal deglutition" (excessive lingual gestures causing multiple swallows required to clear a single bolus) was characteristic of CBS patients. No aspiration was detected. No NIH-SQ cutoff score or combination of subjective complaints predicted an abnormal MBS. Fifty-two percent of the patients had speech apraxia.

CONCLUSIONS

Swallowing and speech disturbances are common in patients with CBS and differ from those previously reported in patients with PSP syndrome. Piecemeal deglutition and speech apraxia are characteristic features of our CBS patients. Although the NIH-SQ cannot predict the results of the more objective MBS in this population, it characterizes the patients' major subjective swallowing complaints.

Central cholinergic dysfunction could be associated with oropharyngeal dysphagia in early Parkinson's disease

Dysphagia is an important issue in the prognosis of Parkinson's disease (PD). Although several studies have reported that oropharyngeal dysphagia may be associated with cognitive dysfunction, the exact relationship between cortical function and swallowing function in PD patients is unclear. Therefore, we investigated the association between an electrophysiological marker of central cholinergic function, which reflected cognitive function, and swallowing function, as measured by videofluoroscopic studies (VFSS). We enrolled 29 early PD patients. Using the Swallowing Disturbance Questionnaire (SDQ), we divided the enrolled patients into two groups: PD with dysphagia and PD without dysphagia. The videofluoroscopic dysphagia scale (VDS) was applied to explore the nature of the dysphagia. To assess central cholinergic dysfunction, short latency afferent inhibition (SAI) was evaluated. We analyzed the relationship between central cholinergic dysfunction and oropharyngeal dysphagia and investigated the characteristics of the dysphagia. The SAI values were significantly different between the two groups. The comparison of each VFSS component between the PD with dysphagia group and the PD without dysphagia group showed statistical significance for most of the oral phase components and for a single pharyngeal phase component. The total score on the VDS was higher in the PD with dysphagia group than in the PD without dysphagia group. The Mini-Mental State Examination and SAI values showed significant correlations with the total score of the oral phase components. According to binary logistic regression analysis, SAI value independently contributed to the presence of dysphagia in PD patients. Our findings suggest that cholinergic dysfunction is associated with dysphagia in early PD and that an abnormal SAI value is a good biomarker for predicting the risk of dysphagia in PD patients.

Rate of aspiration pneumonia in hospitalized Parkinson's disease patients: a cross-sectional study

BACKGROUND

Aspiration pneumonia is an important cause of morbidity and mortality in Parkinson's disease (PD). Clinical characteristics of PD patients in addition to specific alterations in swallowing mechanisms contribute to higher swallowing times and impairment in the effective clearance of the airway. These issues may render patients more prone to dysphagia and aspiration events. We aimed to determine the frequency of aspiration events in a hospitalized PD cohort, and to report the number of in-hospital swallow evaluations.

METHODS

A retrospective single center chart review of 212 PD patients who had 339 hospital encounters was performed from January 2011 to March 2013. Demographics, clinical characteristics, and reasons for encounters were documented. The number of in-hospital aspiration events and the number of swallowing evaluations and also the implementation of aspiration precautions were recorded.

RESULTS

The cohort had a mean age of 74.1 (SD = 10.1) years with mean disease duration of 6 (SD = 6.3) years. Fifty-two hospital encounters (15.3%) were related to a pulmonary cause. In-hospital aspiration pneumonia events were reported in 8 (2.4%) of the total encounters. Swallow evaluations were performed in 25% of all cases, and aspiration precautions were initiated in 32% of the encounters. The data revealed that 1/8 patient had swallowing evaluations performed prior to an aspiration event.

CONCLUSIONS

In-hospital aspiration pneumonia events were reported in 2.4% of the hospitalized PD cohort. Preventive measures and precautions were not routinely performed, however rates of aspiration were relatively low. The results highlight the need for more research into screening and monitoring of swallowing problems in PD patients during hospital encounters.

Gastrointestinal Autonomic Dysfunction in Patients with Parkinson's Disease

Currently, gastrointestinal dysfunctions in Parkinson’s disease (PD) are well-recognized problems and are known to be an initial symptom in the pathological process that eventually results in PD. Gastrointestinal symptoms may result from the involvement of either the central or enteric nervous systems, or these symptoms may be side effects of antiparkinsonian medications. Weight loss, excessive salivation, dysphagia, nausea/gastroparesis, constipation, and defecation dysfunction all may occur. Increased identification and early detection of these symptoms can result in a significant improvement in the quality of life for PD patients.

Localization of mutant ubiquitin in the brain of a transgenic mouse line with proteasomal inhibition and its validation at specific sites in Alzheimer's disease

Loss of protein quality control by the ubiquitin-proteasome system (UPS) during aging is one of the processes putatively contributing to cellular stress and Alzheimer's disease (AD) pathogenesis. Recently, pooled Genome Wide Association Studies (GWAS), pathway analysis and proteomics identified protein ubiquitination as one of the key modulators of AD. Mutations in ubiquitin B mRNA that result in UBB⁺¹ dose-dependently cause an impaired UPS, subsequent accumulation of UBB⁺¹ and most probably depositions of other aberrant proteins present in plaques and neurofibrillary tangles. We used specific immunohistochemical probes for a comprehensive topographic mapping of the UBB⁺¹ distribution in the brains of transgenic mouse line 3413 overexpressing UBB⁺¹. We also mapped the expression of UBB⁺¹ in brain areas of AD patients selected based upon the distribution of UBB⁺¹ in line 3413. Therefore, we focused on the olfactory bulb, basal ganglia, nucleus basalis of Meynert, inferior colliculus and raphe nuclei. UBB⁺¹ distribution was compared with established probes for pre-tangles and tangles and Aβ plaques. UBB⁺¹ distribution found in line 3413 is partly mirrored in the AD brain. Specifically, nuclei with substantial accumulations of tangle-bearing neurons, such as the nucleus basalis of Meynert and raphe nuclei also present high densities of UBB⁺¹ positive tangles. Line 3413 is useful for studying the contribution of proteasomal dysfunction in AD. The findings are consistent with evidence that areas outside the forebrain are also affected in AD. Line 3413 may also be predictive for other conformational diseases, including related tauopathies and polyglutamine diseases, in which UBB⁺¹ accumulates in their cellular hallmarks.