Tongue pressure as a novel biomarker of spinal and bulbar muscular atrophy

High-density surface electromyography evaluation of the suprahyoid muscles in patients with Parkinson's disease

BACKGROUND AND PURPOSE

High-density surface electromyography (HD-sEMG) allows non-invasive analysis of motor unit (MU) activity and recruitment. This study examines MU recruitment features as well as action potential using HD-sEMG in the suprahyoid muscles of patients with Parkinson's disease (PD) and assesses alterations caused by cervical percutaneous interferential current stimulation.

METHODS

Electrical activity of the suprahyoid muscles during tongue elevation was measured using HD-sEMG. Maximum voluntary contraction (MVC) was measured, then the modified entropy, coefficient of variation, correlation coefficient, and root mean square (RMS) were examined. For comparison, HD-sEMG was also conducted on healthy controls. In addition, this study assessed the impact of cervical percutaneous interferential current stimulation on HD-sEMG in patients with PD (Hoehn-Yahr stages 2-4) over 8 weeks.

RESULTS

Twenty-two patients with PD (mean age 71.7 ± 6.0, 7 females) and 14 healthy controls (mean age 74.9 ± 6.1, 7 females) were included. The RMS at 60 % MVC was significantly lower in patients with PD than in healthy controls (p = 0.007). After cervical percutaneous interferential current stimulation, the correlation coefficients at 40 % and 60 % MVC significantly decreased (p = 0.040 and p = 0.048, respectively), and the RMS at 60 % MVC significantly increased (p = 0.035).

CONCLUSION

HD-sEMG of the suprahyoid muscles showed characteristic findings in patients with PD and was able to detect subtle changes due to electrical stimulation intervention. Thus, HD-sEMG could be a promising tool for evaluating swallowing-related muscle conditions and interventions.

Changes in brain functional connectivity between on and off states and their relationship with cognitive impairment in Parkinson's disease

Parkinson's disease (PD) is characterized by motor and non-motor symptoms. Cognitive decline is crucial in disease progression and affect quality of life; however, their underlying mechanisms in PD remain unclear. We explored the relationship between cognitive impairment and functional connectivity (FC) using resting-state functional magnetic resonance imaging in 26 patients with sporadic PD, focusing on the changes in FC between on and off states. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) score. The correlation between MMSE scores and changes in FC values during on and off states was assessed using Pearson's correlation coefficient. The correlation between changes in FC during the on and off periods and cognitive function differed for each cognitive function item. MMSE memory scores were positively correlated with FC between the brainstem and the left cerebral hemisphere. MMSE attention scores were positively correlated with FC between the bilateral thalamus and frontal lobes and negatively correlated with FC between the left cerebral hemispheres. These findings may facilitate our understanding of the neural correlates underlying cognitive impairment in PD and help develop treatment strategies to preserve cognitive function.

Oral functions in adult persons with spinal muscular atrophy compared to a healthy control group: a prospective cross-sectional study with a multimodal approach

BACKGROUND

Oral function tests have been shown to reliably detect impaired bulbar function in adults with spinal muscular atrophy (SMA). Although not routinely recorded, it is known that persons with SMA are affected to varying degrees. Detecting differences in bite and tongue force, endurance, and maximum mouth opening has become particularly promising since the introduction of causal therapy for SMA. This study aimed to compare oral function among adult persons with SMA with different SMA types, walking abilities, and treatment status to a healthy control group.

METHODS

Data from oral function tests conducted on 58 persons with SMA and 45 healthy individuals were analyzed. Differences in oral function between SMA subgroups were pairwise tested and compared to the healthy control group using Wilcoxon rank sum tests.

RESULTS

In an overall comparison, three out of five oral function tests revealed lower values for the SMA group compared to the control group. Subgroup analyses indicated lower scores for most oral function tests in non-ambulatory, untreated patients with SMA type 2 compared to controls. Ambulatory, treated patients with SMA type 3 achieved strength and endurance values comparable to those of healthy individuals.

CONCLUSIONS

The impairment of oral function varies across persons with SMA. Routine measurement of oral function is warranted to determine individual bulbar involvement stages. Further evaluation should be scheduled if indicators such as restricted maximum mouth opening arise. Trial registration DRKS, DRKS00015842. Registered 30 July 2019, https://drks.de/register/de/trial/DRKS00015842/preview .

Assessing the Swallowing Function in Children with Spinal Muscular Atrophy: An Easily Accessible and Objective Multidimensional Approach

Background

Spinal muscular atrophy (SMA), a genetic neuromuscular disease caused by lack of survival of motor neuron (SMN) protein, is characterized by muscular atrophy and respiratory and bulbar dysfunction. While swallowing disorders are common, they remain poorly studied.

Objectives

Our study aimed to explore 1) intraoral pressure measurements with the Iowa Oral Performance Instrument system and the reliability of a Swallowing Function Assessment Questionnaire (SFAQ) in healthy controls, and 2) evaluate their use as swallowing function biomarkers and the evolution of swallowing function over time in children with SMA.

Methods

We recruited 53 healthy children and 27 SMA patients all treated with SMN gene modulator therapy. Participants completed the SFAQ and underwent at least one measurement of maximal oral pressures (lingual, labial, and masseter).

Results

Mean oral normalized pressure index were lower (all sites p < 0.001) and mean SFAQ scores were higher (p < 0.001) in patients compared with healthy controls. Pressure evolution over 1 year in SMA patients for all three oral sites did not show significant differences. SFAQ scores correlated negatively with oral pressures at all three sites in patients.

Conclusions

Both tools provided new insights on the oral and pharyngeal phase of swallowing in SMA patients. In SMA patients, muscle strength in certain crucial anatomical regions during swallowing is weaker than in healthy children.

Improvements in Maximum Bite Force with Gum-Chewing Training in Older Adults: A Randomized Controlled Trial

No specific methods have been officially proposed for the prevention and improvement of oral hypofunction. Therefore, in this randomized controlled trial, we aimed to develop a gum-chewing training program and determine its effects in older adults. A total of 218 older adults, aged 65-85 years, were randomly allocated to the intervention or control groups. The intervention group chewed the experimental gum daily, whereas the control group consumed the experimental granular food daily. The outcome assessments measured the maximum bite force, occlusal contact areas, oral dryness, tongue pressure, tongue and lip functions, masticatory function, and gum-chewing time. The measured values for each outcome were compared between groups using the Mann-Whitney U test and within groups pre- and post-intervention using the Wilcoxon signed-rank test. A total of 211 participants completed the study. After 2 months, the intervention group had a significantly higher maximum bite force than the control group (p = 0.01), indicating that gum-chewing training improved maximum bite force in older adults. This was determined using one type of bite force measuring device. Therefore, it is suggested that gum-chewing training has a high potential to improve oral hypofunction.

Swallowing sound evaluation using an electronic stethoscope and artificial intelligence analysis for patients with amyotrophic lateral sclerosis

Background and purpose

Non-invasive, simple, and repetitive swallowing evaluation is required to prevent aspiration pneumonia in neurological care. We investigated the usefulness of swallowing sound evaluation in patients with amyotrophic lateral sclerosis (ALS) using our new electronic stethoscope artificial intelligence (AI) analysis tool.

Methods

We studied patients with ALS who provided written informed consent. We used an electronic stethoscope, placed a Bluetooth-enabled electronic stethoscope on the upper end of the sternum, performed a 3-mL water swallow three times, and remotely identified the intermittent sound components of the water flow caused at that time by AI, with the maximum value as the swallowing sound index. We examined the correlation between the swallowing sound index and patient background, including swallowing-related parameters.

Results

We evaluated 24 patients with ALS (age 64.0 ± 11.8 years, 13 women, median duration of illness 17.5 months). The median ALS Functional Rating Scale-Revised (ALSFRS-R) score was 41 (minimum 18, maximum 47). In all cases, the mean swallowing sound index was 0.209 ± 0.088. A multivariate analysis showed that a decrease in the swallowing sound index was significantly associated with a low ALSFRS-R score, an ALSFRS-R bulbar symptom score, % vital capacity, tongue pressure, a Mann Assessment of Swallowing Ability (MASA) score, and a MASA pharyngeal phase-related score.

Conclusion

Swallowing sound evaluation using an electronic stethoscope AI analysis showed a correlation with existing indicators in swallowing evaluation in ALS and suggested its usefulness as a new method. This is expected to be a useful examination method in home and remote medical care.

Objective measurement of oral function in adults with spinal muscular atrophy

BACKGROUND

Impairment of bulbar function in adult individuals with spinal muscular atrophy (SMA) usually is not assessed by established motor scores. Measurements of oral function including quantitative muscle and endurance tests are able to detect subtle changes. The aim of this study was to systematically evaluate the measurement of maximum bite force and endurance, maximum tongue pressure and endurance, as well as maximum mouth opening in adult individuals with SMA types 2 and 3.

METHODS

Data from oral function tests in 43 individuals were analyzed. Differences in oral function between individuals with different SMA types and numbers of SMN2 copies were tested. Spearman´s rho correlations among oral function measures themselves as well as with established clinical outcome scales were analyzed.

RESULTS

The absolute maximum measures of oral function (maximum bite force, maximum tongue pressure, maximum mouth opening) were able to discriminate between individuals with different SMA types, individuals with a different number of SMN2 copies and with different walking abilities. The pairwise correlations of the absolute maximum measures of oral function were fair to moderate in size; the same was true for their correlations with the established motor scores. All correlations assessing endurance measures of oral function were weaker and statistically insignificant.

CONCLUSIONS

Among the oral function tests maximum tongue pressure and maximum mouth opening are particulary promising as clinical and sensitive outcome measures for clinical trials. Oral function tests may supplement existing motor scores, in particular concerning specific questions about bulbar function or in severely affected non-ambulatory individuals where mild (treatment-related) changes would otherwise remain undetected. Trial registration DRKS, DRKS00015842. Registered 30 July 2019, https://drks.de/search/de/trial/DRKS00015842.

Influence of age and diet consistency on the oral muscle pressure of orthodontically treated and untreated subjects with normal occlusion and comparison of their 3D facial shape

OBJECTIVES

(1) To investigate the effect of age and diet consistency on maximum lips, tongue and cheek pressure of orthodontically treated and untreated subjects with normal, Class I dental occlusion, (2) to find out whether there is a muscle imbalance between anterior tongue and lip pressure in the same subjects at different ages and (3) to compare the 3D facial shape of treated and untreated individuals.

MATERIAL AND METHODS

Subjects with normal occlusion were prospectively grouped into orthodontically treated/untreated and in children/adolescents/adults. Iowa Oral Performance Instrument was used to record the maximum muscle pressure. Two-way ANOVA and Tukey post hoc test analysed age-specific differences in muscle pressure. Two-way ANCOVA analysed the effect of diet consistency on muscle pressure. Lips and tongue imbalance was analysed using z-scores and 3D faces using a generalized Procrustes analysis.

RESULTS

One hundred thirty-five orthodontically untreated and 114 treated participants were included. Muscle pressure was found to increase with age in both groups, except for the tongue in treated subjects. No differences in the balance between lips and tongue muscle pressure were found, but a higher cheek pressure in untreated adults (p<0.05) was observed. 3D facial shapes showed subtle differences. Untreated subjects with soft diet consistency showed lower lip pressure (p<0.05).

CONCLUSION

Oral muscle pressure of orthodontically treated patients without relapse does not differ from that of untreated patients with Class-I occlusion.

CLINICAL RELEVANCE

This study provides normative lip, tongue and cheek muscle pressure in subjects with normal occlusion, which can be used for diagnosis, treatment planning and stability.

Frictional behaviour of plant proteins in soft contacts: unveiling nanoscale mechanisms

Despite the significance of nanotribology in the design of functional biomaterials, little is known about nanoscale friction in the presence of protein-coated soft contact surfaces. Here, we report a detailed investigation of frictional behaviour of sustainable plant proteins at the nanoscale for the first time, using deformable bio-relevant surfaces that achieve biologically relevant contact pressures. A combination of atomic force microscopy, quartz crystal microbalance with dissipation monitoring, and friction force microscopy with soft polydimethylsiloxane (PDMS, 150 kPa) surfaces was employed to elucidate the frictional properties of model plant proteins, i.e. lupine, pea, and potato proteins at the nanoscale while systematically varying the pH and ionic strength. Interactions of these plant proteins with purified mucins were also probed. We provide the much-needed direct experimental evidence that the main factor dictating the frictional properties of plant proteins is their affinity towards the surface, followed by the degree of protein film hydration. Proteins with high surface affinity, such as pea and potato protein, have better lubricating performance than lupine at the nanoscale. Other minor factors that drive lubrication are surface interactions between sliding bodies, especially at low load, whilst jamming of the contact area caused by larger protein aggregates increases friction. Novel findings reveal that interactions between plant proteins and mucins lead to superior lubricating properties, by combining high surface affinity from the plant proteins and high hydration by mucins. We anticipate that fundamental understanding gained from this work will set the stage for the design of a plethora of sustainable biomaterials and food with optimum nanolubrication performance.

A clinical bulbar assessment scale (CBAS) for amyotrophic lateral sclerosis

INTRODUCTION/AIMS

Comprehensive and valid bulbar assessment scales for use within amyotrophic lateral sclerosis (ALS) clinics are critically needed. The aims of this study are to develop the Clinical Bulbar Assessment Scale (CBAS) and complete preliminary validation.

METHODS

The authors selected CBAS items from among the literature and expert opinion, and content validity ratio (CVR) was calculated. Following consent, the CBAS was administered to a pilot sample of English-speaking adults with El Escorial defined ALS (N = 54) from a multidisciplinary clinic, characterizing speech, swallowing, and extrabulbar features. Criterion validity was assessed by correlating CBAS scores with commonly used ALS scales, and internal consistency reliability was obtained.

RESULTS

Expert raters reported strong agreement for the CBAS items (CVR = 1.00; 100% agreement). CBAS scores yielded a moderate, significant, negative correlation with ALS Functional Rating Scale-Revised (ALSFRS-R) total scores (r = -0.652, p < .001), and a strong, significant, negative correlation with ALSFRS-R bulbar subscale scores (r = -0.795, p < .001). There was a strong, significant, positive correlation with Center for Neurologic Studies Bulbar Function Scale (CNS-BFS) scores (r = 0.819, p < .001). CBAS scores were significantly higher for bulbar onset (mean = 38.9% of total possible points, SD = 22.6) than spinal onset (mean = 18.7%, SD = 15.8; p = .004). Internal consistency reliability (Cronbach's alpha) values were: (a) total CBAS, α = 0.889; (b) Speech subscale, α = 0.903; and (c) Swallowing subscale, α = 0.801.

DISCUSSION

The CBAS represents a novel means of standardized bulbar data collection using measures of speech, swallowing, respiratory, and cognitive-linguistic skills. Preliminary evidence suggests the CBAS is a valid, reliable scale for clinical assessment of bulbar dysfunction.

Development of a functional composite for the evaluation of spinal and bulbar muscular atrophy

This study aimed to develop a functional measurement that combines quantitative motor evaluation index of various body regions in patients with spinal and bulbar muscular atrophy (SBMA). We assessed subjects with SBMA and healthy controls with quantitative muscle strength measurements and functional scales. We selected tongue pressure, grip power, % peak expiratory flow (%PEF), timed walking test, and % forced vital capacity (%FVC) as components. By combining these values with Z-score, we created a functional composite (SBMA functional composite: SBMAFC). We also calculated the standardized response mean to compare the sensitivity of SBMAFC with that of existing measurements. A total of 97 genetically confirmed patients with SBMA and 36 age- and sex-matched healthy controls were enrolled. In the longitudinal analysis, the standardized response mean of SBMAFC was larger than that of existing rating scales. Receiver operating characteristic (ROC) analysis demonstrated that the SBMAFC is capable of distinguishing between subjects with early-stage SBMA and healthy controls. SBMAFC is more sensitive to disease progression than existing functional rating scales and is a potential outcome measure in clinical trials of SBMA.

Improvement in Tongue Pressure Precedes Improvement in Dysphagia in Dermatomyositis

Dysphagia is known to occur in patients with dermatomyositis. However, the sudden-onset dysphagia without other symptoms can make diagnosis and treatment challenging. Two patients who did not have a severe muscle weakness complained of the sudden inability to swallow solids and liquids. The muscle biopsy results showed the perifascicular atrophy, and the patients were diagnosed with dermatomyositis. Videofluoroscopy revealed an inadequate pharyngeal contraction and a decreased upper esophageal sphincter opening with silent aspiration. Both patients showed low tongue pressures. Patient 1 received intravenous and oral methylprednisolone, and patient 2 received intravenous immunoglobulin in addition to intravenous and oral methylprednisolone. Several months after the onset of the dysphagia, the swallowing function of both patients improved. The improvement in tongue pressure preceded an improvement in the subjective and objective measurements of dysphagia. In conclusion, tongue pressure may be useful for predicting early improvement in swallowing function.

Isolated bilateral hypoglossal nerve paralysis following an atlanto-occipital dislocation: A case report

The present report highlights a case of successful treatment of an 11-year-old male patient who presented with an atlanto-occipital dislocation and multiple fractures of the forearm, pelvis, and lower leg because of a fall. The patient experienced dysarthria and paralysis of the tongue, which became completely immobile and could not be moved from side to side, impeding speech. The patient also experienced dysphagia due to the inability to propel food toward the pharynx and chewing attempts resulted in scattering of food residue throughout the oral cavity. The lack of tongue mobility led to saliva accumulation, forcing the patient to swallow frequently, which was possible as larynx movement was unaffected. The other cranial and motor sensory nerves appeared normal. Our diagnostic examinations confirmed the presence of isolated bilateral paralysis of the hypoglossal nerve secondary to traction at the base of the skull. The patient was still unable to protrude his tongue and tongue gradually atrophied two weeks after admission. Electromyography revealed denervation of the tongue and minimal active contraction of the single motor units. Immobilization therapy and rehabilitation therapy were initiated to improve tongue movement, but this was unsuccessful and one month after the accident, the patient's tongue was still atrophied. The patient was placed on a soft food diet and experienced no difficulty in swallowing either saliva or food three months after admission. Tongue mobility was deemed normal. Electromyography six months after the initial episode revealed normal motor unit potentials during contractions. We postulate that compression and stretching of the bilateral hypoglossal nerves against the greater horn of the hyoid bone was a probable cause of the hypoglossal palsy. The use of immobilization and rehabilitation therapy likely supported the recovery of functionality and resulted in a good prognosis.

Relationships between cystatin C and creatinine‐based eGFR with low tongue pressure in Japanese rural community‐dwelling older adults

Background

Sarcopenia is prevalent in patients with chronic kidney disease (CKD), which is defined as a low estimated glomerular filtration rate (eGFR). It has been reported that oral hypofunction characterized by decreased tongue pressure is related to sarcopenia. Although there are several previous reports regarding the association of renal dysfunction with oral hypofunction characterized by low tongue pressure, the association between tongue pressure and renal function is not fully understood.

Methods

This cross‐sectional study included 68 men aged 79.0 ± 4.8 years and 145 women aged 77.3 ± 5.4 years from a rural area in Hyogo Prefecture, Japan. We examined the relationships between cystatin C‐based CKD (CKDcys), creatinine‐based CKD (CKDcre), ratio of cystatin C‐based GFR (eGFRcys) divided by creatinine‐based GFR (eGFRcre): eGFRcys/eGFRcre, and tongue pressure in community‐dwelling older adults.

Results

Tongue pressure was significantly lower in participants with CKDcys than in those without CKDcys in men and women. However, there were no significant differences in tongue pressure with or without CKDcre. Tongue pressure was significantly lower in participants with eGFRcys/eGFRcre <1.0, than in those with eGFRcys/eGFRcre ≧ 1.0 in men. According to the receiver operating characteristic analysis, the optimal cut‐off value of tongue pressure for the presence of CKDcys was 36.6kPa, area under the curve (AUC) 0.74 (specificity 54.8%, sensitivity 84.6%) in men and 31.8kPa, AUC 0.65 (specificity 67.3%, sensitivity 60.5%) in women.

Conclusions

CKDcys but not CKDcre is associated with low tongue pressure. In addition, a lower eGFRcys/eGFRcre ratio is a useful screening marker of low tongue pressure in community‐dwelling older adults.

Acoustic Change Over Time in Spastic and/or Flaccid Dysarthria in Motor Neuron Diseases

PURPOSE

This study aims to investigate acoustic change over time as biomarkers to differentiate among spastic-flaccid dysarthria associated with amyotrophic lateral sclerosis (ALS), spastic dysarthria associated with primary lateral sclerosis (PLS), flaccid dysarthria associated with spinal and bulbar muscular atrophy (SBMA), and to explore how these acoustic parameters are affected by dysarthria severity.

METHOD

Thirty-three ALS patients with mixed flaccid-spastic dysarthria, 17 PLS patients with pure spastic dysarthria, 18 SBMA patients with pure flaccid dysarthria, and 70 controls, all French speakers, were included in the study. Speakers produced vowel-glide sequences targeting different vocal tract shape changes. The mean and coefficient of variation of the total squared change of mel frequency cepstral coefficients were used to capture the degree and variability of acoustic changes linked to vocal tract modifications over time. Differences in duration of acoustic events were also measured.

RESULTS

All pathological groups showed significantly less acoustic change compared to controls, reflecting less acoustic contrast in sequences. Spastic and mixed spastic-flaccid dysarthric speakers showed smaller acoustic changes and slower sequence production compared to flaccid dysarthria. For dysarthria subtypes associated with a spastic component, reduced degree of acoustic change was also associated with dysarthria severity.

CONCLUSIONS

The acoustic parameters partially differentiated among the dysarthria subtypes in relation to motor neuron diseases. While similar acoustic patterns were found in spastic-flaccid and spastic dysarthria, crucial differences were found between these two subtypes relating to variability. The acoustic patterns were much more variable in ALS. This method forms a promising clinical tool as a diagnostic marker of articulatory impairment, even at mild stage of dysarthria progression in all subtypes.

Ratio of urinary N-terminal titin fragment to urinary creatinine is a novel biomarker for amyotrophic lateral sclerosis

OBJECTIVE

We aimed to investigate the validity of urinary N-terminal titin fragment as a biomarker for amyotrophic lateral sclerosis (ALS).

METHODS

We consecutively enrolled patients with ALS (n=70) and healthy controls (HC) (n=43). We assessed the urinary titin N-terminal fragment, urinary neurotrophin receptor p75 extracellular domain, serum neurofilament light chain (NfL), motor functional measurements and prognosis. We used urinary creatinine (Cr) levels to normalise the urinary levels of titin fragment.

RESULTS

Compared with HC, patients with ALS had significantly increased urinary levels of titin N-terminal fragment normalised with Cr (titin/Cr) (ALS, 27.2 pmol/mg/dL; HC, 5.8 pmol/mg/dL; p<0.001), which were correlated with the scores of the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (r=-0.422, p<0.001). A Cox proportional hazards model demonstrated that the high urinary level of titin/Cr was a survival predictor in patients with ALS. Multivariate analysis of prognostic factors showed that the urinary titin/Cr and serum NfL were independent factors for poor prognosis.

CONCLUSIONS

Our findings indicate that urinary N-terminal titin fragment is a non-invasive measure of muscle damage in ALS, which could be applied in disease monitoring and prediction of disease progression, in combination with serum NfL.

Correlation Between Maximal Tongue Pressure and Swallowing Function in Spinal and Bulbar Muscular Atrophy

Background: Spinal and bulbar muscular atrophy (SBMA) is an X-lined motor neuron disease characterized by progressive muscle weakness, bulbar palsy, and dysphagia. Dysphagia is associated with tongue weakness, which is a common manifestation of SBMA. This study aimed to investigate the correlations between tongue pressure and dysphagia in patients with SBMA.

Materials and Methods: Thirty-nine genetically confirmed SBMA patients underwent a videofluoroscopic swallowing study (VFSS) and tongue pressure assessment. Then, we analyzed the maximal tongue pressure (MTP), oral transit time, penetration-aspiration scale (PAS), videofluoroscopic dysphagia scale (VDS), amyotrophic lateral sclerosis functional rating scale-revised (ALSFRS-R), and 6-min walk test (6MWT). Pearson and Spearman correlation coefficients were calculated to analyze the association of the MTP with clinical, swallowing, and functional parameters.

Results: In the correlation analysis, MTP was negatively correlated with disease duration (r = −0.396, p = 0.013) and VDS (r = −0.426, p = 0.007), and positively correlated with ALSFRS-R (r = 0.483, p = 0.002) and 6MWT (r = 0.396, p = 0.013). The bulbar (r = 0.367, p = 0.022) and gross motor (r = 0.486, p = 0.002) domains of the ALSFRS-R were correlated with MTP.

Conclusion: Tongue pressure assessment can be used as a safe and easy tool to assess swallowing function in SBMA patients. Moreover, MTP reflects functional states, including activities of daily living and gait performance, showing it to be a potential biomarker for physical performance in SBMA.

Dysphagia in adult myopathies

Dysphagia (impaired swallowing) is not a rare problem in various neuromuscular disorders, both in the pediatric and the adult patient population. On many occasions such patients are first presented to other medical specialists or health professionals. Disorders of deglutition are probably underrecognized in patients with a neuromuscular disease as a result of patient's and doctor's delay. This review will focus on dysphagia in adults suffering from a myopathy. Dysphagia in myopathies usually affects the oropharyngeal phases which rely mostly on voluntary muscle activity of the mouth, pharynx and upper esophageal sphincter. Dysphagia is known to contribute to a reduction of quality of life and may also lead to increased morbidity and mortality. The review includes an overview on symptomatology and tools of assessments, and elaborates on dysphagia in specific hereditary and acquired myopathies.

Disease mechanism, biomarker and therapeutics for spinal and bulbar muscular atrophy (SBMA)

Spinal and bulbar muscular atrophy (SBMA) is a hereditary neuromuscular disorder caused by CAG trinucleotide expansion in the gene encoding the androgen receptor (AR). In the central nervous system, lower motor neurons are selectively affected, whereas pathology of patients and animal models also indicates involvement of skeletal muscle including loss of fast-twitch type 2 fibres and increased slow-twitch type 1 fibres, together with a glycolytic-to-oxidative metabolic switch. Evaluation of muscle and fat using MRI, in addition to biochemical indices such as serum creatinine level, are promising biomarkers to track the disease progression. The serum level of creatinine starts to decrease before the onset of muscle weakness, followed by the emergence of hand tremor, a prodromal sign of the disease. Androgen-dependent nuclear accumulation of the polyglutamine-expanded AR is an essential step in the pathogenesis, providing therapeutic opportunities via hormonal manipulation and gene silencing with antisense oligonucleotides. Animal studies also suggest that hyperactivation of Src, alteration of autophagy and a mitochondrial deficit underlie the neuromuscular degeneration in SBMA and provide alternative therapeutic targets.

Relationship between tongue pressure and functional oral intake scale diet type in patients with neurological and neuromuscular disorders

INTRODUCTION

Patients with neurological and neuromuscular disorders (NNMD) frequently experience swallowing disorders that increase aspiration pneumonia risk and therefore require specialized diets or tube feeding. Diet type level usually is assessed by video fluoroscopic swallowing study (VFSS). To identify a simpler assessment method, we examined the association between diet type (based on the Functional Oral Intake Scale [FOIS]) diet type and maximum tongue pressure (MTP).

METHODS

From 2011-2020, FOIS diet type level and MTP were assessed in a sample of 927 patients. Of these patients, 186 had Parkinson's disease (PD), 69 had Parkinson-related disease (PRD), 61 had multiple system atrophy (MSA), 42 had spinocerebellar degeneration (SCD), 147 had amyotrophic lateral sclerosis (ALS), 180 had myotonic dystrophy type 1 (DM1), and 242 had Duchenne muscular dystrophy (DMD). VFSS was conducted while patients swallowed water and foods containing barium. MTP measurements were collected the same day. Participants' diet type level was adjusted based on the VFSS, with some participants requiring multiple examinations. Relationships between diet type level and MTP were tested using univariate and Spearman rank correlation analyses.

RESULTS

Mean MTP for the entire NNMD group (25.5 ± 13.1 kPa) was lower than that of healthy elderly individuals, as determined in previous reports. The highest MTP was found in the MSA group (32.2 ± 15.7 kPa) and the lowest in the DM1 group (19.1 ± 9.0 kPa). Diet type level was highest in the MSA group (5.8 ± 1.4) and lowest in the DMD group (5.2 ± 1.7). A significant correlation was observed between diet type level and MTP (R = 0.384, p < 0.001). The optimum MTP cutoff values-detected using ROC curves to predict a requirement to change to a dysphagia diet-was highest in the DMD group (29.0 kPa) and lowest in the ALS group (12.3 kPa).

CONCLUSIONS

The decision to change NNMD patients to a dysphagia diet can be made based on MTP. Modifying a patient's oral diet (FOIS level ≤ 5) should be considered for those with a MTP of 10-25 kPa, with the cutoff value varying by disease.

Improper sitting posture while eating adversely affects maximum tongue pressure

Background/purpose

Although many studies have examined the efficacy of neck and trunk positioning during eating, few studies have examined how the positioning of the lower extremities affects swallowing function. The purpose of this study was to examine how tongue pressure, which is an important factor during swallowing, is affected by eating postures in bed and wheelchair.

Materials and methods

A total of 43 healthy adults (13 men and 30 women; 29.0 ± 5.9 years) and 33 elderly individuals requiring long-term care (14 men and 19 women; 83.6 ± 7.8 years) participated.

In both healthy and elderly participants, tongue pressure was measured in four different postures: a good and poor postures in bed (postures 1 and 2, respectively), and a good and poor postures in a reclining wheelchair (posture 3 and 4, respectively).

Results

Among the healthy participants, the mean tongue pressure was significantly higher in posture 1 (40.2 ± 7.24 kPa) than in posture 2 (37.6 ± 8.68 kPa) or posture 4 (38.2 ± 8.14 kPa) (P < 0.05). Tongue pressure was also significantly higher in posture 3 (41.3 ± 7.75 kPa) than in either posture 2 or 4 (P < 0.05).

Among the elderly participants, the median tongue pressure in posture 1 (16.9 kPa; interquartile range [IQR], 9.4–21.6 kPa) was significantly higher than that in posture 2 (14.1 kPa; IQR, 9.2–21.6 kPa). Tongue pressure in posture 3 (18.5 kPa; IQR, 14.2–26.0 kPa) was significantly higher than that in either posture 1 or 2, and posture 4 (15.9 kPa; IQR, 10.6–22.9 kPa).

Conclusion

Posture during eating can potentially affect tongue pressure.

Tongue thickness measured by ultrasonography is associated with tongue pressure in the Japanese elderly

The term "oral frailty" reflects the fact that oral health is associated with physical frailty and mortality. The gold standard methods for evaluating the swallowing function have several problems, including the need for specialized equipment, the risk of radiation exposure and aspiration, and general physicians not possessing the requisite training to perform the examination. Hence, several simple and non-invasive techniques have been developed for evaluating swallowing function, such as those for measuring tongue pressure and tongue thickness. The aim of this study was to investigate the relationship between tongue thickness ultrasonography and tongue pressure in the Japanese elderly. We evaluated 254 elderly patients, who underwent tongue ultrasonography and tongue pressure measurement. To determine tongue thickness, we measured the vertical distance from the surface of the mylohyoid muscle to the tongue dorsum using ultrasonography. The results of the analyses revealed that tongue thickness was linearly associated with tongue pressure in both sexes. In male participants, dyslipidemia, lower leg circumference, and tongue pressure were independently and significantly associated with tongue thickness. In female participants, body mass index and tongue pressure were independently and significantly associated with tongue thickness. The optimal cutoff for tongue thickness to predict the tongue pressure of < 20 kPa was 41.3 mm in males, and 39.3 mm in females. In the Japanese elderly, tongue thickness using ultrasonography is associated with tongue pressure. Tongue thickness and tongue pressure, which are sensitive markers for oral frailty, decrease with age. We conclude that tongue ultrasonography provides a less invasive technique for determining tongue thickness and predicts oral frailty for elderly patients.

Comparison of the Iowa Oral Performance Instrument and JMS tongue pressure measurement device

Background/purpose

Tongue pressure measurement conveys important information about eating and swallowing function. The Iowa Oral Performance Instrument® (IOPI) and KAY Swallowing Workstation® are internationally used for tongue pressure measurement, but for legal reasons cannot be used in Japan; rather the JMS tongue pressure measurement device® has been approved for use in Japan. However, it is not clear whether measurement obtained with these devices are directly comparable.

Materials and methods

This study investigated the correlation between the maximum tongue pressure data measured by the IOPI and the JMS tongue pressure measurement device in young healthy participants (34 males; 23.2 ± 2.0 years old, and 40 females; 21.4 ± 1.3 years old).

Results

Measurements obtained with these two devices showed significant correlations in the total cohort, and in male and female participants, separately (P < 0.05).

Conclusion

These findings demonstrate that the measurements obtained with the JMS device is comparable to those obtained with the IOPI. In Japan, JMS tongue pressure measurement device is used not only in dysphagia research field, but also geriatrics field, and extensive and detailed investigations has been carried out.

The Maximum Bite Force for Treatment Evaluation in Severely Affected Adult SMA Patients-Protocol for a Longitudinal Study

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder characterized by the degeneration of motor neurons in the spinal cord, and comprises a broad clinical spectrum. With the advent of new therapies (e.g., Nusinersen) for patients of all ages and disease stages, sensitive clinical measures are needed to detect slight changes in muscle force even in immobilized, severely affected patients often unable to move limbs. As for these patients, well-established outcome scales set out to evaluate motor function do not work properly, we propose measurement of maximum bite force which is able to detect subtle changes of bulbar function. Requirements for this approach are mentioned, challenges are discussed, and first insights from a pilot study are presented. Finally, a study design is proposed to evaluate the measurement of maximum bite force during the follow up of SMA patients with and without a disease modifying therapy.

Screening and evaluation tools of dysphagia in adults with neuromuscular diseases: a systematic review

Background:

The purpose of this systematic review was to summarize the different dysphagia screening and evaluation tools, and to identify their measurement properties in adults with neuromuscular diseases (NMDs).

Methods:

A systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search strategy was conducted across three databases (PubMed, CINAHL and ScienceDirect). Measurement properties of each tools and the Quality Index, developed by Downs and Black, were considered for the different investigated studies.

Results:

The search strategy produced 2221 articles. After removal of duplicates and full-text analysis, 19 studies were included. Most of the publications focused on amyotrophic lateral sclerosis (ALS; n = 10) and Duchenne muscular dystrophy (DMD; n = 4). A total of 12 tools, listed as instrumental and noninstrumental examinations, were retrieved. A total of five of them used videofluoroscopic swallow study (VFSS). Measurement properties of the tools are not completely described in detail in many studies. The neuromuscular disease swallowing status scale, a noninstrumental tool, is the only one that assessed all measurement properties in ALS patients. The median score reported for the Quality Index was 16.

Conclusions:

This systematic review identified 12 different tools for the screening and evaluation of dysphagia in adults with NMD. Majority of the studies presented VFSS as a valid and reliable examination to assess dysphagia in ALS and DMD. Other tools were mainly evaluated in ALS patients, but further studies are needed to complete their measurement properties. In other NMDs, no firm conclusion can be made because of insufficient data and heterogeneity of NMDs.

Assessment of Oral Function and Proper Diet Level for Frail Elderly Individuals in Nursing Homes Using Chewing Training Food

OBJECTIVES

We aimed to investigate the relationship between the ability to press Process Lead (PL) in the oral cavity and the tongue pressure and recommended diet form for elderly individuals in nursing homes, using PL normalized physical properties.

DESIGN

Cross-sectional observation study.

SETTING

Geriatric facilities.

PARTICIPANTS

A 100 elderly individuals aged between 67-96 years.

MEASUREMENTS

PL was pressed between the tongue and palate to evaluate its deformation. The thickness was set at 6, 9, and 18 mm. The tongue pressure was measured with a JMS tongue pressure manometer. The number of chewing cycles until an 18-mm thick PL was first swallowed was measured (PL chewing test). The diet was set to level 4, and the recommended form was evaluated by video endoscopic evaluation of swallowing (VE). The results of the PL pressing test and correlations between PL chewing test, tongue pressure, and diet level were statistically examined.

RESULTS

The tongue pressure was significantly decreased in groups that could not press the PL. The PL pressing test and recommended diet form showed a significant correlation, and the elderly with difficulty in pressing the PL had a lower diet level. In addition, the diet level decreased with decreased PL chewing test performance in those without molar occlusion.

CONCLUSIONS

The PL pressing and chewing tests may aid in ascertaining the appropriate diet level. In the future, we would like to verify the usefulness of these tests in determining the diet level of elderly people requiring long-term care at the time of entering the facility.

Positive Effects of "Textured Lunches" Gatherings and Oral Exercises Combined with Physical Exercises on Oral and Physical Function in Older Individuals: A Cluster Randomized Controlled Trial

OBJECTIVES

Proper nutrition and physical exercises are essential to prevent frailty in older adults. Proper masticatory performance and oral function may influence on physical activities as well since the mouth is the entrance of nutrition and digestion. Thus, the present study aimed to test the combined program of specially devised lunch gatherings containing textured foods with oral and physical exercises on the improvement of oral and physical function in community-dwelling older adults.

DESIGN

A Cluster randomized controlled trial; Setting and Participants: Eighty-six community-dwelling older adults in Daito city, Japan, were randomly assigned into control (n = 43) or intervention (n = 43) groups.

INTERVENTION

The control group performed the physical exercise regimen only. The intervention group participated in a 12-week physical and oral exercise program and ate a so-called "munchy lunch" that introduced textured foods with proper nutrients together after performing the physical exercise twice a week following brief dietary instruction at the intervention onset. Physical training and lunch gatherings were held at local public centers.

MEASUREMENTS

The differences in measured variables for physical and oral function between baseline and 12 weeks of intervention were statistically tested.

RESULTS

Oral function as measured by tongue pressure increased significantly in the intervention group (p=0.031), but not in the control group. Physical properties and activities, including body fat percentage and results of the timed up and go test, decreased more significantly in the intervention group than in controls (p<0.05).

CONCLUSIONS

Our findings suggest that a combined program of textured lunch gatherings with oral and physical exercises may improve physical and oral function as a preventative approach for frailty in community-dwelling older adults.

Tongue pressure distribution of individual normal occlusions and exploration of related factors

Background

Tongue plays an important part in oral and maxillofacial system. Measurement of tongue pressure helps to evaluate the performance of tongue movement.

Objectives

To establish a system for measuring tongue pressure against hard palate and to preliminarily explore pressure distribution of individual normal occlusions and the relationship with dental arch form.

Methods

A total of 19 volunteers of individual normal occlusions out of 189 dental students met inclusion criteria (nine males, ten females, aged 25.53 ± 0.96 years). A force‐sensing resistor device was used to measure tongue pressure at rest and functional state (swallowing). We observed tongue pressure of four channel (anterior, posterior and lateral sides of hard palate) in sitting, supine position and swallowing. We analysed pressure differences according to gender and explored correlation relationship between tongue pressure and dental arch width and length using 3D digital maxillary image.

Results

In rest, tongue pressure against hard palate increased from front to back in both sitting and supine position, without gender differences. When swallowing saliva, the pressure at lateral sides of females was found significantly higher than that of males. Bivariate correlation analysis revealed duration of swallowing was positively correlated with BMI and weight at posterior region and positively correlated with palatal length at anterior palate. The greater the dental arch width, the smaller the pressure of swallowing in the anterior and lateral region.

Conclusion

In rest, there was consistent pressure of tongue against hard palate. The pressure increased significantly during swallowing, especially in females. Tongue pressure was related to dental arch length, width, BMI and weight.

Biomarkers of Spinal and Bulbar Muscle Atrophy (SBMA): A Comprehensive Review

Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy's disease, is a rare, X-linked, late onset neuromuscular disorder. The disease is caused by a CAG trinucleotide repeat expansion in the first exon of the androgen receptor gene. It is characterized by slowly progressive lower motor neurons degeneration, primary myopathy and widespread multisystem involvement. Respiratory involvement is rare, and the condition is associated with a normal life expectancy. Despite a plethora of therapeutic studies in mouse models, no effective disease-modifying therapy has been licensed for clinical use to date. The development of sensitive monitoring markers for the particularly slowly progressing pathology of SBMA is urgently required to aid future clinical trials. A small number of outcome measures have been proposed recently, including promising biochemical markers, which show correlation with clinical disability and disease-stage and progression. Nevertheless, a paucity of SBMA-specific biomarker studies persists, delaying the development of monitoring markers for pharmaceutical trials. Collaborative efforts through international consortia and multicenter registries are likely to contribute to the characterization of the natural history of the condition, the establishment of disease-specific biomarker panels and ultimately contribute to the development of disease-modifying drugs.

Study protocol for the MEXiletine hydrochloride administration trial: a placebo-controlled, randomised, double-blind, multicentre, crossover study of its efficacy and safety in spinal and bulbar muscular atrophy (MEXPRESS)

INTRODUCTION

Spinal and bulbar muscular atrophy (SBMA) is a slowly progressive neuromuscular disease. Cold exposure often leads to worsening of motor symptoms including paresis. Although mexiletine hydrochloride administration has been shown to be effective for the treatment of several muscular diseases, its effectiveness in SBMA has not been validated to date. The trial will test it as a symptomatic drug for cold paresis. This study is the first trial to evaluate the efficacy and safety of mexiletine hydrochloride administration in patients with SBMA.

METHODS AND ANALYSIS

A placebo-controlled, randomised, double-blind, multicentre, crossover clinical trial will be conducted to assess the safety and efficacy of mexiletine hydrochloride in patients with SBMA. The eligible patients will be assigned randomly in a 1:1 ratio to two groups in a double-blind manner. Participants will take mexiletine hydrochloride (300 mg/day) or a placebo orally three times a day for 4 weeks (period 1). After a 1-week washout period, participants will take the other drug for 4 weeks (period 2). The primary endpoint is the difference in distal latencies between room temperature and cold exposure conditions.

ETHICS AND DISSEMINATION

This study will be conducted in compliance with the Helsinki Declaration and the Ethical Guidelines for Medical and Health Research Involving Human Subjects by the Japanese government and has been approved by the ethics committee of Nagoya University Graduate School of Medicine, as a central institutional review board, and by each facility. The results will be disseminated in peer-reviewed journals and at scientific conferences.

TRIAL REGISTRATION NUMBER

UMIN000026150; Pre-results.

Reproducibility assessment of an instrument for measuring the axial force of the tongue

PURPOSE

Evaluate the reproducibility of Forling, a portable instrument for measuring axial tongue force.

METHODS

Axial force of the tongue was measured in 49 individuals (30 women and 19 men) aged 18-25 years using the Forling portable instrument. Measurements were performed in three days at intervals of 7±2 days. On each day, three 7-second measurements were performed with one-minute intervals between them. The coefficient of variation, Wilcoxon paired test, and intraclass correlation coefficient were used in the statistical analysis of the data. Maximum and mean tongue force values were analyzed, and comparison between them was performed using three approaches: the mean of the three values; the mean of the two highest values; the highest value of each measurement.

RESULTS

In the analysis of mean tongue force, the coefficient of variation was considered desirable and the intraclass correlation coefficient was acceptable. Significant differences were observed regarding the maximum value between the second and third days, mean of the two highest values and mean of the three values between the first and second days and the second and third days. In the analysis of maximum tongue force, the coefficient of variation and the intraclass correlation coefficient were acceptable. Significant difference was found only in the comparison between the second and third days.

CONCLUSION

Good reproducibility of the data obtained with the use of the Forling portable instrument was observed.

Oral hypofunction in the older population: Position paper of the Japanese Society of Gerodontology in 2016

BACKGROUND

There is growing international interest in identifying the effects of ageing on oral health and on appropriate strategies for managing oral disorders. The Japanese Society of Gerodontology (JSG), as the official representative of researchers and clinicians interested in geriatric dentistry in Japan, makes several recommendations on the concept of "oral hypofunction."

AIMS

This study proposes diagnostic criteria and management strategies to reduce the risk of oral hypofunction among older people.

CONCEPTUAL FRAMEWORK

We define oral hypofunction as a presentation of 7 oral signs or symptoms: oral uncleanness; oral dryness; decline in occlusal force; decline in motor function of tongue and lips; decline in tongue pressure; decline in chewing function; and decline in swallowing function. The criteria of each symptom were determined based on the data of previous studies, and oral hypofunction was diagnosed if the criteria for 3 or more signs or symptoms were met.

CONCLUSIONS

We recommend that more evidence should be gathered from clinical studies and trials to clarify our diagnostic criteria and management strategies.

Treatment with Creatine Monohydrate in Spinal and Bulbar Muscular Atrophy: Protocol for a Randomized, Double-Blind, Placebo-Controlled Trial

Background

Although spinal and bulbar muscular atrophy (SBMA) has been classified as a motor neuron disease, several reports have indicated the primary involvement of skeletal muscle in the pathogenesis of this devastating disease. Recent studies reported decreased intramuscular creatine levels in skeletal muscles in both patients with SBMA and transgenic mouse models of SBMA, which appears to contribute to muscle weakness.

Objective

The present study aimed to examine the efficacy and safety of oral creatine supplementation to improve motor function in patients with SBMA.

Methods

A randomized, double-blind, placebo-controlled, three-armed clinical trial was conducted to assess the safety and efficacy of creatine therapy in patients with SBMA. Patients with SBMA eligible for this study were assigned randomly in a 1:1:1 ratio to each group of placebo, 10 g, or 15 g daily dose of creatine monohydrate in a double-blind fashion. Participants took creatine or placebo orally 3 times a day for 8 weeks. Outcome measurements were results of neurological assessments, examinations, and questionnaires collected at baseline and at weeks 4, 8, and 16 after a washout period. The primary endpoint was the change in handgrip strength values from baseline to week 8. The secondary endpoints included the following: results of maximum voluntary isometric contraction tests of extremities; tongue pressure; results of the 15-foot timed walk test and the rise from bed test; modified quantitative myasthenia gravis score; respiratory function test results; activities of daily living assessed with the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale and the Spinal and Bulbar Muscular Atrophy Functional Rating Scale; skeletal muscle mass measured with dual-energy X-ray absorptiometry; urinary 8-hydroxydeoxyguanosine levels; and questionnaires examining the quality of life, swallowing function, and fatigue.

Results

Participant enrollment in the trial started from June 2014 and follow-up was completed in July 2015. The study is currently being analyzed.

Conclusions

This is the first clinical trial evaluating creatine therapy in SBMA. Given that creatine serves as an energy source in skeletal muscles, recovery of intramuscular creatine concentration is expected to improve muscle strength.

Trial Registration

University Hospital Medical Information Network Clinical Trials Registry UMIN000012503; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000014611 (Archived by WebCite at http://www.webcitation.org/6xOlbPkg3).

Quantitative Assessment of Swallowing Dysfunction in Patients with Spinal and Bulbar Muscular Atrophy

Objective This study aimed to evaluate swallowing dysfunction in patients with spinal and bulbar muscular atrophy and to identify the most appropriate method of assessing swallowing dysfunction using a videofluoroscopic swallowing study. Methods In the videofluoroscopic swallowing study, patients were instructed to swallow 3 mL of 40% weight/volume barium sulfate twice, and the pharyngeal residue was measured. We used three different methods to quantify the pharyngeal barium residue and an eight-point scale to evaluate the laryngeal penetration leading to aspiration pneumoniae. Patients We assessed 111 patients with spinal and bulbar muscular atrophy who weren't undergoing disease-specific treatment. Results Our results showed that the pharyngeal barium residue after initial swallowing correlated better with the bulbar-related functional rating scales than that after multiple deglutition. This correlation was vague when the data from patients whose barium residue was >50% were eliminated. In addition, evaluating the pharyngeal residue after initial swallowing proved to be the most sensitive method with regard to laryngeal penetration. Conclusion This study showed that the pharyngeal barium residue after initial swallowing was the most appropriate parameter for quantitatively assessing the degree of dysphagia using a videofluoroscopic swallowing study and suggests that this method may predict laryngeal penetration and aspiration in patients with spinal and bulbar muscular atrophy.

Tongue strength in patients with subacute myelo-optico-neuropathy

Subacute myelo-optico-neuropathy (SMON) is a neurodegenerative disease that may be caused by overdose or prolonged oral administration of clioquinol. Recently, dysphagia has attracted attention as a complication of SMON. To investigate lingual control in SMON, we examined patients with SMON using assessments of maximum tongue pressure, compared with dysphagia-related diseases, such as sporadic inclusion body myositis (sIBM) and amyotrophic lateral sclerosis (ALS), and healthy volunteer. The mean maximum tongue pressure (P_max) in patients with SMON was 14.7 ± 5.8 kPa, while it was 33.6 ± 4.4 kPa in the controls. In contrast, the mean P_max for patients with ALS with or without bulbar involvement was 7.8 ± 2.7 kPa and 34.4 ± 5.7 kPa, respectively, while it was 29.4 ± 8.2 kPa in patients with sIBM. P_max values correlated with lower limb weakness in SMON patients. Decreases in P_max may be involved in the development of dysphagia in patients with SMON.

Characteristics of tongue and pharyngeal pressure in patients with neuromuscular diseases

Background

Tongue and pharyngeal pressure is an essential factor associated with the swallowing function; however, little is known about the difference in tongue and pharyngeal pressure between neuromuscular diseases. This study aimed to characterize tongue and pharyngeal pressure in myotonic dystrophy type 1 (DM1), Duchenne muscular dystrophy (DMD), and amyotrophic lateral sclerosis (ALS) patients.

Methods

This study recruited 17 DMD patients, 32 DM1 patients, and 26 ALS patients. They underwent separate measurements of tongue and pharyngeal pressure under videofluoroscopy, swallowing 5 mL of barium water. We measured the largest change in pharyngeal pressure in the hypopharynx and the upper esophageal sphincter (UES) over several swallows.

Results

The mean tongue pressure (TP) was greatest in the DMD group than in the other groups (p<0.01). There was a significant difference in pressure changes in the hypopharynx and UES between the DM1 group and other groups (p<0.01). Significant correlations were observed between pressure change in the UES and the patient’s age in the DMD group (R=–0.500, p=0.045) and between pressure change in the hypopharynx and TP in the DM1 group (R=0.421, p=0.016). There was a significant correlation between pressure change in the hypopharynx and disease severity in the ALS group (R=0.435, p=0.030).

Conclusion

Patients with DMD, DM1, and ALS have weakness in the muscles involved in swallowing; however, the results of this study suggested that each disorder has a distinctive profile of impairment in the swallowing function.

Swallowing markers in spinal and bulbar muscular atrophy

OBJECTIVE

We examined the characteristics of dysphagia in spinal and bulbar muscular atrophy, a hereditary neuromuscular disease causing weakness of limb, facial, and oropharyngeal muscles via a videofluoroscopic swallowing study, and investigated the plausibility of using these outcome measures for quantitative analysis.

METHODS

A videofluoroscopic swallowing study was performed on 111 consecutive patients with genetically confirmed spinal and bulbar muscular atrophy and 53 age- and sex-matched healthy controls. Swallowing of 3-mL liquid barium was analyzed by the Logemann's Videofluorographic Examination of Swallowing worksheet.

RESULTS

Of more than 40 radiographic findings, the most pertinent abnormal findings in patients with spinal and bulbar muscular atrophy, included vallecular residue after swallow (residue just behind the tongue base), nasal penetration, and insufficient tongue movement (P < 0.001 for each) compared with healthy controls. Quantitative analyses showed that pharyngeal residue after initial swallowing, oral residue after initial swallowing, multiple swallowing sessions, and the penetration-aspiration scale were significantly worse in these patients (P ≤ 0.005 for each) than in controls. In patients with spinal and bulbar muscular atrophy, laryngeal penetration was observed more frequently in those without subjective dysphagia.

INTERPRETATION

Dysphagia of spinal and bulbar muscular atrophy was characterized by impaired tongue movement in the oral phase and nasal penetration followed by pharyngeal residues, which resulted in multiple swallowing sessions and laryngeal penetration. Although major limitations of reproducibility and radiation exposure still exist with videofluoroscopy, pharyngeal residue after initial swallowing and the penetration-aspiration scale might serve as potential outcome measures in clinical studies.

Kennedy disease (X-linked recessive bulbospinal neuronopathy): A comprehensive review from pathophysiology to therapy

Kennedy's disease, also known as spinal and bulbar muscular atrophy (SBMA), is a rare, adult-onset, X-linked recessive neuromuscular disease caused by expansion of a CAG repeat sequence in exon 1 of the androgen receptor gene (AR) encoding a polyglutamine (polyQ) tract. The polyQ-expanded AR accumulates in nuclei, and initiates degeneration and loss of motor neurons and dorsal root ganglia. While the disease has long been considered a pure lower motor neuron disease, recently, the presence of major hyper-creatine-kinase (CK)-emia and myopathic alterations on muscle biopsy has suggested the presence of a primary myopathy underlying a wide range of clinical manifestations. The disease, which affects male adults, is characterized by muscle weakness and atrophy localized proximally in the limbs, and bulbar involvement. Sensory disturbances are associated with the motor phenotype, but may be subclinical. The most frequent systemic symptom is gynecomastia related to androgen insensitivity, but other abnormalities, such as heart rhythm and urinary disturbances, have also been reported. The course of the disease is slowly progressive with normal life expectancy. The diagnosis of SBMA is based on genetic testing, with 38 CAG repeats taken as pathogenic. Despite several therapeutic attempts made in mouse models, no effective disease-modifying therapy is yet available, although symptomatic therapy is beneficial for the management of the weakness, fatigue and bulbar symptoms.

Kennedy's disease 1234 scale: Preliminary design and test

Kennedy's disease (KD), also known as spinal and bulbar muscular atrophy (SBMA), is a rare x-linked genetic disorder which is characterized by muscle weakness and atrophy. In previous clinical trials, KD patients had been assessed using the ALSFRS scale, which was specifically designed for ALS patients. However, the progression of KD is very slow, and thus, the ALSFRS does not accurately reflect changes in the clinical condition of KD patient. Here, we developed the KD 1234 scale which designed specially for KD. We evaluated KD 1234 and ALSFRS in 81 KD patients and 100 healthy age-matched male participants. Of 81 cases, 52 were followed up after 32months. Scale reliability was assessed using inter-rater reliability, split-half reliability and internal consistency reliability (Cronbach's α coefficient). Scale validity was evaluated using content and structure validity. Longitudinal analysis was performed. The results showed the KD 1234 scale was simple and easy to operate, with good reliability, validity and reactivity. We think this new scale can quantitatively evaluate the clinical condition of KD patients and any changes in this condition, and is thus suitable for clinical studies.

Phonologic and Acoustic Analysis of Speech Following Glossectomy and the Effect of Rehabilitation on Speech Outcomes

PURPOSE

Changes in acoustic features in the perioperative phase for elucidating the mechanisms of articulation disorder and the effect of perioperative rehabilitation were studied prospectively.

MATERIALS AND METHODS

Sixty-two patients with 62 tongue cancer were divided into a partial glossectomy group (n = 40) and a reconstruction group (n = 22). Acoustic characteristics were analyzed during the preoperative and postoperative periods and after rehabilitation using the first and second formants of the vowels /a/, /i/, and /u/; the triangular vowel space area (tVSA); and the slopes of formant transitions.

RESULTS

In the 2 groups, decreases in the tVSA and formant slopes were found from the preoperative to the postoperative period, and the acoustic characteristics of the reconstruction group especially improved to preoperative values after rehabilitation. Analysis of the postoperative period showed that acoustic characteristics were altered at the site of surgical resection.

CONCLUSION

Changes of acoustic variables are related to excision size and site, suggesting the distinctive tongue portion for the articulation of each speech sound. Perioperative rehabilitation could activate the articulators and increase the range of movement of the remaining tongue, especially the preserved anterior tongue.

Prediction of Pneumonia in Acute Stroke Patients Using Tongue Pressure Measurements

Swallowing dysfunction caused by stroke is a risk factor for aspiration pneumonia. Tongue pressure measurement is a simple and noninvasive method for evaluating swallowing dysfunction. We have hypothesized that low tongue pressure may be able to predict pneumonia occurrence in acute stroke patients. Tongue pressure was measured using balloon-type equipment in 220 acute stroke patients. The modified Mann Assessment of Swallowing Ability (MASA) score was evaluated independently on the same day. Tongue pressure was measured every week thereafter. An improvement in tongue pressure was observed within the first 2 weeks. Receiver operating curve analysis was performed to determine the ability of tongue pressure to predict modified MASA score <95, which suggests swallowing dysfunction. The optimal cutoff for tongue pressure was 21.6 kPa (χ2 = 45.82, p<0.001, sensitivity 95.9%, specificity 91.8%, area under the curve = 0.97). The tongue pressure was significantly lower in patients with pneumonia than in those without pneumonia. Using a Cox proportional hazard model for pneumonia onset with a cutoff tongue pressure value of 21.6 kPa and adjustment for age, sex, and National Institutes of Health Stroke Scale score at admission, the tongue pressure had additional predictive power for pneumonia onset (hazard ratio, 7.95; 95% confidence interval, 2.09 to 52.11; p = 0.0013). In the group with low tongue pressure, 27 of 95 patients showed improvement of tongue pressure within 2 weeks. Pneumonia occurred frequently in patients without improvement of tongue pressure, but not in patients with improvement (31/68 and 2/27, p<0.001). Tongue pressure is a sensitive indicator for predicting pneumonia occurrence in acute stroke patients.

Impaired muscle uptake of creatine in spinal and bulbar muscular atrophy

Objective

The aim of this study was to explore the pathomechanism underlying the reduction of serum creatinine (Cr) concentrations in spinal and bulbar muscular atrophy (SBMA).

Methods

We evaluated blood chemistries, motor function, and muscle mass measured by dual‐energy X‐ray absorptiometry in male subjects with SBMA (n = 65), amyotrophic lateral sclerosis (ALS; n = 27), and healthy controls (n = 25). We also examined the intramuscular concentrations of creatine, a precursor of Cr, as well as the protein and mRNA expression levels of the creatine transporter (SLC6A8) in autopsy specimens derived from subjects who had SBMA and ALS and disease controls. Furthermore, we measured the mRNA expression levels of SLC6A8 in cultured muscle cells (C2C12) transfected with the polyglutamine‐expanded androgen receptor (AR‐97Q).

Results

Serum Cr concentrations were significantly lower in subjects with SBMA than in those with ALS (P < 0.001), despite similar muscle mass values. Intramuscular creatine concentrations were also lower in with the autopsied specimen of SBMA subjects than in those with ALS subjects (P = 0.018). Moreover, the protein and mRNA expression levels of muscle SLC6A8 were suppressed in subjects with SBMA. The mRNA levels of SLC6A8 were also suppressed in C2C12 cells bearing AR‐97Q.

Interpretation

These results suggest that low serum Cr concentration in subjects with SBMA is caused by impaired muscle uptake of creatine in addition to being caused by neurogenic atrophy. Given that creatine serves as an energy source in skeletal muscle, increasing muscle creatine uptake is a possible therapeutic approach for treating SBMA.

The relationship between physical symptoms and health-related quality of life in oculopharyngeal muscular dystrophy

INTRODUCTION

Oculopharyngeal muscular dystrophy (OPMD) causes ptosis, dysphagia, and limb weakness. Health-related quality of life (HRQoL) and its relationship to physical symptoms was investigated.

METHODS

The 36-item Short Form (SF-36) was completed by 89 participants in the U.S. OPMD Registry. Multiple hierarchical regression was used to determine the relative contributions of dysphagia severity and lower extremity functional impairment to the physical (PCS) and mental (MCS) components of the SF-36.

RESULTS

HRQoL was reduced in OPMD compared with population norms. Lower extremity functional impairment explained a significant proportion of variance in PCS and MCS. Dysphagia symptom severity explained a moderate amount of variance only in MCS. Dysphagia symptom severity had the strongest associations with general health perception and social functioning domains.

CONCLUSIONS

Lower extremity functional impairment in OPMD deserves attention due to its large influence on HRQoL. Both generic and dysphagia-specific measures are necessary to assess HRQoL in OPMD.

Wet, volatile, and dry biomarkers of exercise-induced muscle fatigue

Background

The physiological background of exercise-induced muscle fatigue(EIMUF) is only poorly understood. Thus, monitoring of EIMUF by a single or multiple biomarkers(BMs) is under debate.

After a systematic literature review 91 papers were included.

Results

EIMUF is mainly due to depletion of substrates, increased oxidative stress, muscle membrane depolarisation following potassium depletion, muscle hyperthermia, muscle damage, impaired oxygen supply to the muscle, activation of an inflammatory response, or impaired calcium-handling. Dehydration, hyperammonemia, mitochondrial biogenesis, and genetic responses are also discussed. Since EIMUF is dependent on age, sex, degree of fatigue, type, intensity, and duration of exercise, energy supply during exercise, climate, training status (physical fitness), and health status, BMs currently available for monitoring EIMUF have limited reliability. Generally, wet, volatile, and dry BMs are differentiated. Among dry BMs of EIMUF the most promising include power output measures, electrophysiological measures, cardiologic measures, and questionnaires. Among wet BMs of EIMUF those most applicable include markers of ATP-metabolism, of oxidative stress, muscle damage, and inflammation. VO₂-kinetics are used as a volatile BM.

Conclusions

Though the physiology of EIMUF remains to be fully elucidated, some promising BMs have been recently introduced, which together with other BMs, could be useful in monitoring EIMUF. The combination of biomarkers seems to be more efficient than a single biomarker to monitor EIMUF. However, it is essential that efficacy, reliability, and applicability of each BM candidate is validated in appropriate studies.

Onset Manifestations of Spinal and Bulbar Muscular Atrophy (Kennedy's Disease)

Spinal and bulbar muscular atrophy (SBMA) is regarded as a disorder with adult onset between third and fifth decade of life. However, there is increasing evidence that SBMA may start already before adulthood. The present study investigated the following: (1) Which clinical manifestations have been described so far in the literature as initial manifestations? (2) Which was the age at onset of these manifestations? and (3) Is age at onset dependent on the CAG-repeat length if non-motor manifestations are additionally considered? Data for this review were identified by searches of MEDLINE using appropriate search terms. Onset manifestations in SBMA can be classified as frequent, rare, motor, non-motor, or questionable. Frequent are muscle weakness, cramps, fasciculations/twitching, tremor, dysarthria, dysphagia, or gynecomastia. Rare are myalgia, easy fatigability, exercise intolerance, polyneuropathy, hyper-CKemia, under-masculinized genitalia, scrotal hypospadias, microphallus, laryngospasm, or oligospermia. Questionable manifestations include sensory disturbances, cognitive impairment, increased pituitary volume, diabetes, reduced tongue pressure, elevated creatine-kinase, or low androgens/high estrogens. Age at onset is highly variable ranging from 4-76 years. Non-motor manifestations develop usually before motor manifestations. Age at onset depends on what is considered as an onset manifestation. Considering non-motor onset manifestations, age at onset is independent of the CAG-repeat size. In conclusion, age at onset of SBMA depends on what is regarded as onset manifestation. If non-motor manifestations are additionally considered, age at onset is independent of the CAG-repeat length. Since life expectancy is hardly reduced in SBMA, re-investigation of patients from published studies with regard to their initial disease profiles is recommended.