Swallowing intentional off-state in aging and Alzheimer's disease: preliminary study

A self-reported cross-sectional study on the oral function and the quality of life in children with stunted growth

BACKGROUND

Failure to catch up with growth in toddlerhood will stunt elementary school children, which continues to cognitive decline and oral motor coordination. Verbal motor skills play an essential role in the oral function of the stomatognathic system, which includes mastication, swallowing, and speech. Therefore, early attention to oral function disorders of the stomatognathic system can avoid complications in children's nutritional status and quality of life.

OBJECTIVE

The objective of this study was to analyze the correlation of oral function of the stomatognathic system with Oral Health-Related Quality of Life (OHRQoL) in stunting children.

METHODS

This cross-sectional study correlates with 58 children aged 7-12 years with a history of stunting in toddlerhood from the Pasir Jambu District, Bandung Regency. The oral function of the stomatognathic system was evaluated by Adapted Orofacial Myofunctional Assessment Protocol and OHRQoL with Child Oral Health Impact Profile Short Form (COHIP-SF 19).

RESULTS

The results were statistically analyzed using Spearman's rank correlation and Kendall's coefficient of concordance correlation tests. The results showed that the research subjects had a significant relationship in each variable and the three variables of the oral function of the stomatognathic system (chewing, swallowing, and speech) with OHRQoL with a p-value <0.05. The study concluded that the oral function of the stomatognathic system (chewing, swallowing, and speech) is related to OHRQoL in children with stunted growth.

Evaluation of Swallowing Function according to the Stage of Alzheimer's Disease

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disease, and swallowing difficulties may occur as the disease progresses. Dysphagia has many consequences, such as aspiration and pneumonia. In particular, in the advanced stage, approximately 70% of the causes of death in AD involve aspiration pneumonia. Therefore, it is vital to assess the presence or absence of dysphagia in AD.

OBJECTIVE

This study aims to describe swallowing difficulty across the stages of AD.

METHODS

Thirty-five AD patients were evaluated. The Mini-Mental State Examination was conducted. A bedside water swallow test (BWST) and the Eating Assessment Tool (EAT-10) were administered. Finally, fiberoptic endoscopic evaluation of swallowing was used to evaluate residual, aspiration and penetration conditions.

RESULTS

EAT-10 scores, BWST results, and penetration-aspiration status were statistically significantly different according to AD stage (p < 0.05). Among all patients, 74.3% had residue, 25.7% had penetration, and 2.9% had aspiration.

CONCLUSIONS

This study has demonstrated that swallowing dysfunction begins at a mild stage and progressively worsens toward the advanced stage in patients with AD. At all stages of AD, residue was observed, and this poses a risk for the development of penetration-aspiration. Therefore, it is necessary to evaluate the early dysphagia of individuals.

Shifting Tides Toward a Proactive Patient-Centered Approach in Dysphagia Management of Neurodegenerative Disease

Purpose Persons with neurodegenerative disease frequently develop comorbid dysphagia as part of their disease process. Current "reactive" approaches to dysphagia management address dysphagia once it manifests clinically and consist of compensatory approaches. The purpose of this article is to propose a paradigm shift in dysphagia management of patients with neurodegenerative disease from a "reactive to proactive" approach by highlighting amyotrophic lateral sclerosis (ALS) and dementia as case examples. Method The authors present several areas of special consideration for speech-language pathologists (SLPs) treating dysphagia in patients with neurodegenerative disease. The drawbacks of historical "reactive" approaches to dysphagia management are described. Concepts of functional reserve for swallowing and homeostenosis are discussed. A "proactive" patient-centered paradigm of care for these patients is proposed with evidence to support its importance. A rationale for use of this approach in patients with ALS and dementia is provided with strategies for implementation. Results When treating dysphagia in patients with neurodegenerative disease, SLPs must balance a variety of factors in their decision making, including disease severity and expected progression, cultural considerations, goals of care, patient empowerment, and caregiver support. Reactive approaches to dysphagia management in these populations are problematic in that they disempower patients by focusing on use of compensatory techniques (e.g., diet modification, postural changes, feeding tube placement). Proactive approaches that employ rehabilitative interventions to increase functional reserve, such as resistance training, may result in improvement or maintenance of swallowing function longer into disease progression. An interdisciplinary team with early SLP involvement is necessary. Conclusions SLPs play a critical role in the management of dysphagia in patients with neurodegenerative disease and should be integrated early in the care of these patients. By focusing on a proactive patient-centered approach, patients with neurodegenerative conditions, such as ALS and dementia, will experience improved quality of life and health outcomes for a longer time.

Functional Adaptation of Oromotor Functions and Aging: A Focused Review of the Evidence From Brain Neuroimaging Research

“Practice makes perfect” is a principle widely applied when one is acquiring a new sensorimotor skill to cope with challenges from a new environment. In terms of oral healthcare, the traditional view holds that restoring decayed structures is one of the primary aims of treatment. This assumes that the patient’s oromotor functions would be recovered back to normal levels after the restoration. However, in older patients, such a structural–functional coupling after dental treatment shows a great degree of individual variations. For example, after prosthodontic treatment, some patients would adapt themselves quickly to the new dentures, while others would not. In this Focused Review, I argue that the functional aspects of adaptation—which would be predominantly associated with the brain mechanisms of cognitive processing and motor learning—play a critical role in the individual differences in the adaptive behaviors of oromotor functions. This thesis is critical to geriatric oral healthcare since the variation in the capacity of cognitive processing and motor learning is critically associated with aging. In this review, (a) the association between aging and the brain-stomatognathic axis will be introduced; (b) the brain mechanisms underlying the association between aging, compensatory behavior, and motor learning will be briefly summarized; (c) the neuroimaging evidence that suggests the role of cognitive processing and motor learning in oromotor functions will be summarized, and critically, the brain mechanisms underlying mastication and swallowing in older people will be discussed; and (d) based on the current knowledge, an experimental framework for investigating the association between aging and the functional adaptation of oromotor functions will be proposed. Finally, I will comment on the practical implications of this framework and postulate questions open for future research.

Nonspecific effects of gap paradigm on swallowing

OBJECTIVE

Analogous to the gap paradigm in experiments for saccadic eye movements with very short reaction times, we hypothesized that the initiation of oropharyngeal swallowing movements guided by visual cues are encouraged under experimental conditions using a similar gap paradigm.

METHODS

A red visual cue indicating to hold a bolus in the mouth and a blue one indicating to swallow the bolus were sequentially provided on a computer display to 11 healthy participants. The gap period between these cues varied from 0 to 800ms. Swallowing kinetics and kinematics were recorded using surface electromyography and a laser displacement sensor, respectively.

RESULTS

In comparison with the no-gap paradigm, the delay from the onset of muscle activities to initiation of movement significantly decreased with a 100- (p<0.01) and 200-ms (p<0.005) gap period. With other gap periods, no significant change was detected in the delay.

CONCLUSIONS

Initiation of visually guided swallowing was enhanced by a gap paradigm of 100-200ms. Wrist flexion was boosted in a similar manner. Thus, the gap effect may be a generalized warning effect.

SIGNIFICANCE

Our findings might provide insights into the contribution of the basal ganglia to volitional swallowing.

Diagnostic Assessment and Management of Dysphagia in Patients with Alzheimer's Disease

A growing concern in patients affected by Alzheimer's disease (AD) is dysphagia, or swallowing impairment, which leads to malnutrition, dehydration, weight loss, functional decline and fear of eating and drinking, as well as a decrease in the quality of life. Thus the diagnostic assessment of dysphagia in patients with AD is imperative to ensure that they receive effective management, avoiding complications, and reducing comorbidity and mortality in such a growing population. Dysphagia management requires a multidisciplinary approach considering that no single strategy is appropriate for all patients. However, evidence for clinical diagnostic assessment, interventions, and medical management of dysphagia in these patients are still limited: few studies are reporting the evaluation and the management among this group of patients. Here we analyzed the most recent findings in diagnostic assessment and management of swallowing impairment in patients affected by AD.

Functional magnetic resonance and swallowing: critical literature review

Introduction

Aspects of the neuroanatomical representation of swallowing have been investigated in humans through brain mapping techniques, such as functional magnetic resonance imaging (fMRI).

Objective

This critical qualitative review of the literature analyzed international scientific publications in the PubMed database that investigated the activation of the central nervous system in humans during the act of swallowing.

Methods

This investigation was limited to articles that investigated adults older than 18 years, published in English or Portuguese, between January 2002 and December 2013. Publications that did not have access to the full text, that were repeated by overlapping keywords, case studies, literature reviews, letters to the editor, and those not directly related to the topic of the investigation were excluded.

Results

A total of 649 articles were identified, of which 21 matched the inclusion criteria.

Conclusion

The main purpose of the manuscripts that investigate the swallowing process through fMRI were: to characterize swallowing in different pathologies; to compare swallowing in different age groups; to describe brain activation in different stimulation conditions. These studies indicate multiple cortical regions involved in swallowing control. Overall, the studies indicate that fMRI is a non-invasive and quantitative method that allows the investigation of characteristics that are quite often not clinically visible.

A novel once-daily fixed-dose combination of memantine extended release and donepezil for the treatment of moderate to severe Alzheimer's disease: two phase I studies in healthy volunteers

BACKGROUND

Combining two standard-of-care medications for Alzheimer's disease (AD) into a single once-daily dosage unit may improve treatment adherence, facilitate drug administration, and reduce caregiver burden. A new fixed-dose combination (FDC) capsule containing 28 mg memantine extended release (ER) and 10 mg donepezil was evaluated for bioequivalence with co-administered commercially available memantine ER and donepezil, and for bioavailability with regard to food intake.

METHODS

Two phase I, single-dose, randomized, open-label, crossover studies were conducted in 18- to 45-year-old healthy individuals. In MDX-PK-104 study, fasting participants (N = 38) received co-administered memantine ER and donepezil or the FDC. In MDX-PK-105 study, participants (N = 36) received three treatments: intact FDC taken while fasting or after a high-fat meal, or FDC contents sprinkled on applesauce while fasting. Standard pharmacokinetic parameters for memantine and donepezil were calculated from the plasma concentration time-curve using non-compartmental analyses. Linear mixed-effects models were used to compare: (a) FDC versus co-administered individual drugs; (b) FDC fasted versus with food; and (c) FDC sprinkled on applesauce versus FDC intact, both fasted. Safety parameters were also evaluated.

RESULTS

The FDC capsule was bioequivalent to co-administered memantine ER and donepezil. There was no significant food effect on the bioavailability of the FDC components. There were no clinically relevant differences in time to maximum plasma concentration or safety profiles across treatments.

CONCLUSIONS

An FDC capsule containing 28 mg memantine ER and 10 mg donepezil is bioequivalent to commercially available memantine ER and donepezil, and bioavailability is not affected by food intake or sprinkling of capsule contents on applesauce.

Compensatory recombination phenomena of neurological functions in central dysphagia patients

We speculate that cortical reactions evoked by swallowing activity may be abnormal in patients with central infarction with dysphagia. The present study aimed to detect functional imaging features of cerebral cortex in central dysphagia patients by using blood oxygen level-dependent functional magnetic resonance imaging techniques. The results showed that when normal controls swallowed, primary motor cortex (BA4), insula (BA13), premotor cortex (BA6/8), supramarginal gyrus (BA40), and anterior cingulate cortex (BA24/32) were activated, and that the size of the activated areas were larger in the left hemisphere compared with the right. In recurrent cerebral infarction patients with central dysphagia, BA4, BA13, BA40 and BA6/8 areas were activated, while the degree of activation in BA24/32 was decreased. Additionally, more areas were activated, including posterior cingulate cortex (BA23/31), visual association cortex (BA18/19), primary auditory cortex (BA41) and parahippocampal cortex (BA36). Somatosensory association cortex (BA7) and left cerebellum in patients with recurrent cerebral infarction with central dysphagia were also activated. Experimental findings suggest that the cerebral cortex has obvious hemisphere lateralization in response to swallowing, and patients with recurrent cerebral infarction with central dysphagia show compensatory recombination phenomena of neurological functions. In rehabilitative treatment, using the favorite food of patients can stimulate swallowing through visual, auditory, and other nerve conduction pathways, thus promoting compensatory recombination of the central cortex functions.

Differential psychophysiological interactions of insular subdivisions during varied oropharyngeal swallowing tasks

Abstract The insula is a highly integrated cortical region both anatomically and functionally. It has been shown to have cognitive, social-emotional, gustatory, and sensorimotor functions. Insular involvement in both normal and abnormal swallowing behavior is well established, yet its functional connectivity is unclear. Studies of context-dependent connectivity, or the connectivity during different task conditions, have the potential to reveal information about synaptic function of the insula. The goal of this study was to examine the functional connectivity of specific insular regions (ventral anterior, dorsal anterior, and posterior) with distant cortical regions during four swallowing conditions (water, sour, e-stim, and visual biofeedback) using generalized psychophysiological interactions (gPPI). In 19 healthy adults, we found that the visual biofeedback condition was associated with the most and strongest increases in functional connectivity. The posterior insula/rolandic operculum regions had the largest clusters of increases in functional connectivity, but the ventral anterior insula was functionally connected to a more diverse array of cortical regions. Also, laterality assessments showed left lateralized increases in swallowing functional connectivity. Our results are aligned with reports about the insula's interconnectivity and extensive involvement in multisensory and cognitive tasks.

Tracking cognitive change over 24 weeks with longitudinal functional magnetic resonance imaging in Alzheimer's disease

BACKGROUND

Previous studies have revealed that functional magnetic resonance imaging (fMRI) blood oxygen level-dependent (BOLD) signal in specific brain regions correlates with cross-sectional performance on standardized clinical trial measures in Alzheimer's disease (AD); however, the relationship between longitudinal change in fMRI-BOLD signal and neuropsychological performance remains unknown.

OBJECTIVE

To identify changes in regional fMRI-BOLD activity that tracks change in neuropsychological performance in mild AD dementia over 6 months.

METHODS

Twenty-four subjects (mean age 71.6) with mild AD dementia (mean Mini Mental State Examination 21.7, Global Clinical Dementia Rating 1.0) on stable donepezil dosing participated in two task-related fMRI sessions consisting of a face-name paired associative encoding memory paradigm 24 weeks apart during a randomized placebo-controlled pharmaco-fMRI drug study. Regression analysis was used to identify regions where the change in fMRI activity for Novel > Repeated stimulus contrast was associated with the change scores on postscan memory tests and the Free and Cued Selective Reminding Test (FCSRT).

RESULTS

Correlations between changes in postscan memory accuracy and changes in fMRI activity were observed in regions including the angular gyrus, parahippocampal gyrus, inferior frontal gyrus and cerebellum. Correlations between changes in FCSRT-free recall and changes in fMRI were observed in regions including the inferior parietal lobule, precuneus, hippocampus and parahippocampal gyrus.

CONCLUSION

Changes in encoding-related fMRI activity in regions implicated in mnemonic networks correlated with changes in psychometric measures of episodic memory retrieval performed outside the scanner. These exploratory results support the potential of fMRI activity to track cognitive change and detect signals of short-term pharmacologic effect in early-phase AD studies.