Deglutition dynamics of patients with obstructive sleep apnea.

Objectives: In the present study, we performed a detailed analysis of deglutitive dynamics during sleep in patients with obstructive sleep apnea (OSA) using a methodology developed by Sato et al. We hypothesized that the frequency of deglutition would decrease with increasing severity of OSA. The aim of this study is to clarify the involvement of deglutitive dynamics during sleep in OSA by investigating the correlations between deglutition and sleep parameters. Methods: This study included 30 adult patients with OSA. To analyze deglutition dynamics during sleep, surface electromyography recordings of the suprahyoid and thyrohyoid neck muscles, which are involved in deglutition, were performed simultaneous with conventional polysomnography. The "index of deglutition" was defined as the frequency of deglutition per hour of sleep. We examined correlations between this index and sleep parameters (apnea-hypopnea index [AHI], apnea index, hypopnea index, and lowest blood oxygen saturation). Results: By analyzing the obtained polysomnography and electromyography waveforms, we identified two deglutition patterns with and without respiratory arousal during sleep. We found a significant negative correlation between the index of deglutition in sleep stage 1 and the AHI, with a correlation coefficient of -0.48. (p=0.02). Conclusions: In the current study, we distinguished deglutition during sleep with and without arousal. In addition we discovered a significant negative correlation between the index of deglutition in sleep stage 1 and the AHI. This new finding will provide a platform for future research on OSA in aspiration pneumonia.

Prevalence and outcome of pre-onset frailty in patients with acute stroke.

BACKGROUND: Frailty in older individuals is an underappreciated condition that affects the incidence and/or prognosis of stroke. OBJECTIVES: We evaluated the prevalence of pre-onset frailty in patients with acute first-onset and recurrent strokes and association between pre-onset frailty and functional disability at hospital discharge. METHODS: This prospective cohort study included 210 acute stroke patients admitted to the Stroke Unit of Nippon Medical School Hospital during November 2021-June 2022. The mean participant age was 79.2 ± 7.4 years. Age, sex, pre-onset frailty, body mass index (BMI), stroke type, medical history, and National Institutes of Health Stroke Scale (NIHSS) score at admission were evaluated. Frailty was defined as a clinical frailty scale (CFS) score ≥ 5. Frailty prevalence was calculated for all patients, and scores of functional disabilities at discharge were evaluated using modified Rankin scale. RESULTS: Overall frailty prevalence was 31% in all stroke patients, with 24% and 47% of first-onset and recurrent strokes, respectively. Pre-onset frailty, NIHSS score at admission, age, stroke type, previous stroke, sex, BMI, dyslipidemia, and atrial fibrillation were significantly associated with functional disability at discharge. Logistic regression analysis revealed that CFS score, NIHSS score at admission, and previous stroke were independent predictors of functional disability at discharge. CONCLUSIONS: Approximately one-fourth of patients with first-onset stroke had pre-onset frailty; the rate doubled in recurrent stroke; these rates appear to be much larger than rate in healthy individuals. Pre-onset frailty, a negative independent factor affecting functional disability at discharge, is important for pre-onset frailty evaluation and rehabilitation intervention in acute stroke patients.

[Rehabilitation Therapy for Acute Brain Disease].

Early mobilization and rehabilitation therapy are becoming more critical in acute stroke, traumatic brain injury, and neurological disorder. Better functional prognosis for patients are obtained by performing comprehensive early mobilization and rehabilitation by a multidisciplinary team, generally within 48 hours after the onset. Early and frequent mobilization and rehabilitation therapy are recommended unless systemic management is paramount, such as hemodynamic instability, increased intracranial pressure, or active bleeding. Future considerations to be verified include implementation of rehabilitation in the very early phase(e.g., within 24 hours after the onset), selection of patients(e.g., when to start rehabilitation for each disease type), amount of exercise load in the intensive care unit(ICU), and content of training at the early stage. In addition, there are still few established methods for evaluating motor activity that can be performed in bed. It is also necessary to consider the nature of the rehabilitation team and leadership that were poorly addressed.

Comparison of electromyography, sound, bioimpedance, and high-resolution manometry for differentiating swallowing and vocalization events.

OBJECTIVES: Non-invasive surface recording devices used for detecting swallowing events include electromyography (EMG), sound, and bioimpedance. However, to our knowledge there are no comparative studies in which these waveforms were recorded simultaneously. We assessed the accuracy and efficiency of high-resolution manometry (HRM) topography, EMG, sound, and bioimpedance waveforms, for identifying swallowing events. METHODS: Six participants randomly performed saliva swallow or vocalization of "ah" 62 times. Pharyngeal pressure data were obtained using an HRM catheter. EMG, sound, and bioimpedance data were recorded using surface devices on the neck. Six examiners independently judged whether the four measurement tools indicated a saliva swallow or vocalization. Statistical analyses included the Cochrane's Q test with Bonferroni correction and the Fleiss' kappa coefficient. RESULTS: Classification accuracy was significantly different between the four measurement methods (P < 0.001). The highest classification accuracy was for HRM topography (>99%), followed by sound and bioimpedance waveforms (98%), then EMG waveform (97%). The Fleiss' kappa value was highest for HRM topography, followed by bioimpedance, sound, and then EMG waveforms. Classification accuracy of the EMG waveform showed the greatest difference between certified otorhinolaryngologists (experienced examiners) and non-physicians (naive examiners). CONCLUSION: HRM, EMG, sound, and bioimpedance have fairly reliable discrimination capabilities for swallowing and non-swallowing events. User experience with EMG may increase identification and interrater reliability. Non-invasive sound, bioimpedance, and EMG are potential methods for counting swallowing events in screening for dysphagia, although further study is needed.

Effect of Tongue-Hold Swallow on Pharyngeal Contractile Properties in Healthy Individuals.

Tongue-hold swallow (THS) is a swallow exercise in which an individual swallows saliva while holding the anterior portion of the tongue between the front teeth. The effect of THS on pharyngeal contractile vigor is still unclear. The purpose of this study was to quantify THS using high-resolution manometry with a contractile integral analysis. Twenty-two healthy participants performed three different saliva swallow tasks: normal swallow, weak THS (in which the tongue was protruded 1 cm outside the upper incisors), and strong THS (in which the tongue was protruded 2 cm outside the upper incisors). The participants repeated each task twice randomly. Pharyngeal and upper esophageal sphincter metrics, including the pharyngeal contractile integral, were analyzed. Both weak and strong THS enhanced the velopharyngeal contractile integral and peak pressure compared with normal swallow (P < 0.01). THS also prolonged mesopharyngeal contraction (P < 0.01). Holding the tongue anteriorly during swallow requires significant biomechanical changes to pharyngeal contractile properties at the superior and middle pharyngeal constrictor levels; thus, it may serve as a resistance exercise for the muscles that are involved in bolus propulsion.

Neuronal intranuclear inclusion disease presenting with dysphagia: a report of three cases.

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease that is pathologically characterized by the presence of eosinophilic hyaline intranuclear inclusions in neurons, astrocytes, and specific somatic cells. Previously reported cases of NIID displayed various neurological symptoms, including dementia, muscle weakness, ataxia, etc. However, dysphagia associated with NIID have rarely been reported. Here, we report on three cases of NIID with dysphagia. Bolus mastication and transport were impaired in all three cases. Delay of the initiation of pharyngeal swallowing and silent aspiration was observed in two cases. Combined with the brain magnetic resonance imaging (MRI) findings, oropharyngeal dysphagia associated with NIID was suggested to be attributed to diffuse subcortical lesions.

Oropharyngeal Dysphagia and Aspiration Pneumonia Following Coronavirus Disease 2019: A Case Report.

Cranial nerve involvement is a finding often observed in patients infected with severe acute respiratory syndrome coronavirus 2 during the pandemic outbreak of coronavirus disease 2019 (COVID-19). To our knowledge, this is the first report of oropharyngeal dysphagia associated with COVID-19. A 70-year-old male developed dysphagia and consequent aspiration pneumonia during recovery from severe COVID-19. He had altered sense of taste and absent gag reflex. Videoendoscopy, videofluorography, and high-resolution manometry revealed impaired pharyngolaryngeal sensation, silent aspiration, and mesopharyngeal contractile dysfunction. These findings suggested that glossopharyngeal and vagal neuropathy might have elicited dysphagia following COVID-19. The current case emphasizes the importance of presuming neurologic involvement and concurrent dysphagia, and that subsequent aspiration pneumonia might be overlooked in severe respiratory infection during COVID-19.

Mstu1, an APSES transcription factor, is required for appressorium-mediated infection in Magnaporthe grisea.

The APSES protein family includes important transcriptional regulators of morphological processes in ascomycetes. We identified a deletion mutant of the APSES protein Mstu1 in Magnaporthe grisea that showed reduced conidiation and mycelial growth. Mstu1 formed a number of appressoria comparable to the wild type, although appressorium formation was delayed. In M. grisea, rapid transfer of conidial glycogen and lipid droplets to incipient appressoria is required for appressorial turgor generation, which the fungus uses to penetrate plant cuticles. Appressorial turgor was low in mstu1 and the mutant was deficient in appressorium-mediated invasion of rice leaves. The transfer of conidial glycogen and lipid droplets was remarkably delayed in mstu1, and a consequent delay in degradation of these conidial reserves was observed. Our results indicate that Mstu1 is required for appressorium-mediated infection due to its involvement in the mobilization of lipids and glycogen.

MgLig4, a homolog of Neurospora crassa Mus-53 (DNA ligase IV), is involved in, but not essential for, non-homologous end-joining events in Magnaporthe grisea.

In many eukaryotic organisms, the non-homologous end-joining (NHEJ) system is a major pathway for the repair of DNA double-strand breaks (DSBs). DNA ligase IV is a component of the NHEJ system and is strictly required for the NHEJ system in Saccharomyces cerevisiae and in Neurospora crassa. To investigate the functions of DNA Ligase IV in Magnaporthe grisea, we generated deletion mutants of MGLIG4, which encodes a homolog of N. crassa DNA Ligase IV. Mutants (mglig4) showed no defects in asexual or sexual growth, and were fully pathogenic. Compared to the wild-type, mglig4 exhibited weak sensitivity to a DNA-damaging agent, camptothecin. In addition, the frequency of targeted-gene replacement was relatively elevated in mglig4, although this varied in a gene-dependent manner. Surprisingly, non-homologous integration of DNA was frequently observed in mglig4 transformants. Our results demonstrate that MgLig4 is involved in, but not essential for, the NHEJ system in M. grisea.