Disabilities of the pharynx in amyotrophic lateral sclerosis as demonstrated by cineradiography

Trends in Research Literature Describing Dysphagia in Motor Neuron Diseases (MND): A Scoping Review

Dysphagia in motor neuron diseases (MNDs) is highly complex, affecting all stages of swallowing and leading to impaired swallowing safety and efficiency. In order to explore the degree to which research is capturing the symptom of dysphagia in MND, we conducted a scoping review of the existing literature. The primary aims of this review were to identify common themes within the literature on dysphagia in MND, explore patterns and trends in research focus, and identify if any imbalances exist between the research themes related to dysphagia description and management. A comprehensive search strategy yielded 1690 unique articles for review. Following relevance screening, a total of 157 articles were included in the synthesis. Relevant data and keywords were extracted from each article and grouped into themes. Frequency estimates were calculated for each theme to identify trends across research literature. Swallowing impairment in MNDs is described in a variety of ways across current research. The most commonly reported theme was Aspiration/Penetration, mentioned in 73.2% of all included articles; a significant imbalance was identified between reports of swallowing safety and efficiency (p = 0.008). The most frequently reported theme related to dysphagia management was Enteral Nutrition, and very few studies have reported on the efficacy of Rehabilitation/Compensatory recommendations. It is suggested that researchers and clinicians remain mindful of imbalances and gaps in research, and aim to characterize dysphagia in MNDs in a comprehensive manner. Further research investigating discrete, measureable changes in swallowing pathophysiology would be beneficial to delineate the key factors contributing to impaired swallowing safety and efficiency.

Digital cineradiographic study of swallowing in patients with amyotrophic lateral sclerosis

PURPOSE

This study was performed to evaluate the usefulness of digital cineradiography in detecting swallowing disorders in dysphagic patients affected by amyotrophic lateral sclerosis (ALS) with a view to planning an adequate therapeutic approach.

MATERIAL AND METHODS

From January 2005 to September 2006, 23 patients (10 men and 13 women; mean age 41.3+/-8.6 years) affected by ALS were evaluated with digital cineradiography to assess the grade of dysphagia. All patients were classified using the Hillel ALS Severity Scale (ALSSS). All examinations were performed with radiocontrolled equipment provided with a digital C-arm.

RESULTS

The cineradiographic technique enabled us to differentiate patients with disorders of the oral (17/23) and/or pharyngeal (19/23) swallowing phase from those without swallowing dysfunction (4/23). In 14/23 patients, passage of contrast medium into the upper airways was observed during swallowing, whereas in 5/23 cases, aspiration of contrast medium into the lower airways was recorded.

CONCLUSIONS

The videofluoroscopic swallowing study has high diagnostic capabilities in the evaluation of swallowing disorders, as it is able to identify the degree and causes of impairment. In addition, the study proved useful for planning speech therapy and for follow-up in patients with ALS.

Surface electromyographic activity of the submental muscles during swallow and expiratory pressure threshold training tasks

The use of expiratory muscle strength trainers improves parameters related to pulmonary function, speech, and cough in both healthy and patient populations. Recently, it has been speculated that expiratory strength training may alter the force generation of muscles used during the swallow process. Specifically, the use of the trainer may result in increased activation of the submental muscle complex. Support for this hypothesis was tested by examining the timing and amplitude of submental muscle activity obtained using surface EMG. These muscles are known to be important for normal swallow function. Twenty participants (10 males, 10 females; mean age = 29 years) were recruited to participate in a one-session study. Participants were asked to perform two swallows (saliva swallow and water swallow) and develop an expiratory pressure set at 25% and 75% of their maximum expiratory pressure (MEP) using an expiratory muscle strength trainer. These tasks allowed comparison of muscle activity during both the swallow and expiratory tasks completed with the trainer. Results indicated that the patterns of activation in the submental muscle group while training on the expiratory device had longer duration of activation with higher amplitude of EMG activity when compared with the swallowing condition. These findings indicate that expiratory muscle strength training (EMST) increases motor unit recruitment of the submental muscle complex. Discussion centers on the potential benefit of EMST as a treatment modality for dysphagia characterized by decreased amplitude of hyoid movement during swallowing.

Longitudinal analysis of progression of dysphagia in amyotrophic lateral sclerosis

OBJECTIVE

To investigate the progression of dysphagia in amyotrophic lateral sclerosis (ALS) using videofluoroscopy (VF), according to two different scales: the duration following bulbar symptom onset, and the ALS severity scale (ALSSS).

METHODS

Seventy-two VF examinations, on 50 ALS patients, were performed at various time points, and the change in VF findings in the oral and pharyngeal phases was analyzed over time following bulbar symptom onset. The change according to advancement of the ALS severity scale was also assessed.

RESULTS

Delayed bolus transport from the oral cavity to the pharynx, and bolus stasis at the pyriform sinus (PS), were seen in about half of the patients with no bulbar complaints. In contrast, upper esophageal sphincter (UES) opening was relatively well maintained in the late stage of dysphagia. The other parameters, such as bolus holding in the oral cavity, constriction of the pharynx, and elevation of the larynx, became worse over time following bulbar symptom onset. These parameters on VF examination also became worse as the ALSSS advanced; however, even patients in the group with normal eating habits showed disturbed bolus transport from the mouth to the pharynx, weak constriction of the pharynx, and bolus stasis at the PS. Generally, dysfunction had progressed dramatically, in most of the parameters, in the patients that required modification of food; however, UES opening and elevation of the larynx were relatively well maintained in advanced-ALSSS patients.

CONCLUSION

In this study, we clearly show the progression pattern of dysphagia in ALS, and we also emphasize that VF is a useful tool to follow swallowing function in ALS patients. From our results, it would be useful to perform VF by 6 months following bulbar symptom onset, because VF can contribute to rehabilitation or appropriate diet modification; and later, around 1 year following bulbar symptom onset, VF should again be performed, since ALS patients show wide-ranging nutrition intake patterns, and they need assessment to introduce intervention, such as tube feeding, according to their varying status of dysphagia, around at this time point.

Videomanofluorometric study in amyotrophic lateral sclerosis

OBJECTIVE

To elucidate the time-course changes of swallowing function in amyotrophic lateral sclerosis (ALS) by videomanofluorometry.

STUDY DESIGN

Videomanofluorometry was conducted on 21 patients with ALS, who were divided into five groups according to type of disease and according to the length of time following the appearance of bulbar symptoms.

METHODS

Videomanofluorometry, which is videofluoroscopic and manometric study conducted simultaneously, was performed on patients in the five groups, and swallowing function in each group was evaluated. Some of the patients were followed up by videomanofluorometry performed several times, and their swallowing function changes over time were investigated.

RESULTS

A decrease of swallowing pressure first appeared in the oropharynx, then the hypopharynx became involved. Oropharyngeal swallowing pressure had already decreased to approximately 50 mm Hg within 6 months after the appearance of bulbar symptoms; however, hypopharyngeal swallowing pressure was relatively maintained until 1 year after the onset of bulbar symptoms. Most of the patients with ALS maintained normal upper esophageal sphincter relaxation, but upper esophageal sphincter spasm was seen in some patients with ALS. Aspiration was seen in eight cases, five of which showed upper esophageal sphincter spasm.

CONCLUSIONS

Patients with ALS gradually face the danger of aspiration as decreases of oropharyngeal and hypopharyngeal swallowing pressure progress. Upper esophageal sphincter spasm occurs in some patients with ALS, and it is an important cause of aspiration. Both videofluoroscopic and manometric evaluation are necessary to assess these conditions, and they are quite useful for follow-up of swallowing function in patients with ALS.

Pathophysiological mechanisms of oropharyngeal dysphagia in amyotrophic lateral sclerosis

We investigated the pathophysiological mechanisms of dysphagia in amyotrophic lateral sclerosis. Forty-three patients with sporadic amyotrophic lateral sclerosis were examined by clinical and electrophysiological methods that objectively measured the oropharyngeal phase of voluntarily initiated swallowing, and these results were compared with those obtained from 50 age-matched control subjects. Laryngeal movements were detected by a piezoelectric sensor and EMG of submental muscles, and needle EMG of the cricopharyngeal muscle of the upper oesophageal sphincter of both the amyotrophic lateral sclerosis and control groups was recorded during swallowing. Amyotrophic lateral sclerosis patients with dysphagia displayed the following abnormal findings. (i) Submental muscle activity of the laryngeal elevators, which produce reflex upward deflection of the larynx during wet swallowing, was significantly prolonged whereas the laryngeal relocation time of the swallowing reflex remained within normal limits. (ii) The cricopharyngeal sphincter muscle EMG demonstrated severe abnormalities during voluntarily initiated swallows. The opening of the sphincter was delayed and/or the closure occurred prematurely, the total duration of opening was shortened and, at times, unexpected motor unit bursts appeared during this period. (iii) During voluntarily initiated swallows there was significant lack of co-ordination between the laryngeal elevator muscles and the cricopharyngeal sphincter muscle. These results point to two pathophysiological mechanisms that operate to cause dysphagia in amyotrophic lateral sclerosis patients. (i) The triggering of the swallowing reflex for the voluntarily initiated swallow is delayed and eventually abolished, whereas the spontaneous reflexive swallows are preserved until the preterminal stage of amyotrophic lateral sclerosis. (ii) The cricopharyngeal sphincter muscle of the upper oesophageal sphincter becomes hyper-reflexic and hypertonic. As a result, the laryngeal protective system and the bolus transport system of deglutition lose their co-ordination during voluntarily initiated swallowing. We conclude that these pathophysiological changes are related mainly to the progressive degeneration of the excitatory and inhibitory corticobulbar pyramidal fibres.

Analysis of the Pharyngoesophageal Pressure Profile in Amyotrophic Lateral Sclerosis

Treatment of dysphagia resulting from bulbar amyotrophic lateral sclerosis has included cricopharyngeal myotomy for many years but is successful in only a minority of cases. The purpose of this study was to explore the rationale for this procedure with modern manometric techniques. The results of pharyngoesophageal manometry in 13 patients with amyotrophic lateral sclerosis were compared with 13 age- and sex-matched healthy volunteers by Mann-Whitney analysis. There was no significant difference between patients and control subjects in distal esophageal or lower esophageal sphincter motility nor any pressure parameter of pharyngoesophageal motility. Separate analysis of the seven significantly dysphagic subjects showed a significantly reduced upper esophageal sphincter after-contraction amplitude during water and bread swallows in patients than in control subjects. These data suggest that the dysphagia of amyotrophic lateral sclerosis is not due to upper esophageal sphincter spasm and that treatment by cricopharyngeal myotomy may be inappropriate.

Neurogenic dysphagia: what is the cause when the cause is not obvious?

The potential causes of neurogenic oropharyngeal dysphagia in cases in which the underlying neurologic disorder is not readily apparent are discussed. The most common basis for unexplained neurogenic dysphagia may be cerebrovascular disease in the form of either confluent periventricular infarcts or small, discrete brainstem stroke, which may be invisible by magnetic resonance imaging. The diagnosis of occult stroke causing pharyngeal dysphagia should not be overlooked, because this diagnosis carries important treatment implications. Motor neuron disease producing bulbar palsy, pseudobulbar palsy, or a combination of the two can present as gradually progressive dysphagia and dysarthria with little if any limb involvement. Myopathies, especially polymyositis, and myasthenia gravis are potentially treatable disorders that must be considered. A variety of medications may cause or exacerbate neurogenic dysphagia. Psychiatric disorders can masquerade as swallowing apraxia. The basis for unexplained neurogenic dysphagia can best be elucidated by methodical evaluation including careful history, neurologic examination, videofluoroscopy of swallowing, blood studies (CBC, chemistry panel, creatine kinase, B12, thyroid screening, and anti-acetylcholine receptor antibodies), electromyography, and magnetic resonance imaging (MRI) of the brain, plus additional procedures such as lumbar puncture and muscle biopsy as indicated. Little is known about aging and neurogenic dysphagia, specifically the relative contributions of natural age-related changes in the oropharynx and of diseases of the elderly, including periventricular MRI abnormalities, in producing dysphagia symptoms and videofluoroscopic abnormalities in this population.

Amyotrophic lateral sclerosis: Part 1. Clinical features, pathology, and ethical issues in management

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease of the motor system in adults that occurs in sporadic, familial, and Western Pacific forms. Involvement of non-motor pathways has been increasingly recognized, both clinically and pathologically. Although the usual course is relentlessly progressive with death in half the cases within three years from onset, it can sometimes be protracted. Degeneration and loss of large motor neurons in the cerebral cortex, brainstem, and cervical and lumbar spinal cord are characteristic. Marked reduction in the number of large myelinated fibers is notable in the cervical and lumbar ventral roots. Peripheral nerves show reduced numbers of large myelinated fibers, acute axonal degeneration at all levels, and distal axonal atrophy. Motor end-plates reveal small or absent nerve terminals. Subclinical non-motor system involvement includes neuronal loss in Clarke's nucleus and dorsal root ganglia, degeneration of non-motor tracts in the spinal cord, loss of receptors in the dorsal horns of the spinal cord, and myelinated fiber loss with segmental demyelination in sensory and mixed nerves. The serious implications of the diagnosis of ALS make it mandatory to exclude similar potentially treatable disorders. Management should be multidisciplinary, and discussions with the patient and family members should be frank and frequent. Discussions about ventilatory support should take place early in the disease so that death from respiratory failure can be prevented, when that is desired, and conversely to obviate the discontent and anger that accompany involuntary life on a ventilator.

Oropharyngeal dysphagia Manometric and cine esophagraphic findings

The manometric and cineradiographic features of 14 patients with oropharyngeal dysphagia are described. Failure of the upper-esophageal sphincter (UES) to relax completely and incoordination of UES relaxation with pharyngeal contraction were noted as was poor initiation of swallows and disorganization of pharyngeal contraction. The relative merits of cine esophagography and esophageal manometry in evaluating oropharyngeal dysphagia are assessed, and a functional classification for this disorder is proposed. Clinical improvement in 4 of 5 patients who underwent UES myotomy for severe intractable dysphagia did not always correlate with improvement in manometric and cine studies.