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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the mechanisms of muscle fatigue in ALS. In the muscles of ALS patients and healthy control subjects, we examined (1) fatigue using measurements of muscle force, (2) energy metabolism using phosphorus-31 magnetic resonance spectroscopy, and (3) activation using neurophysiologic measures and MRI. During 25 minutes of intermittent isometric exercise of the tibialis anterior muscle, both maximum voluntary and tetanic force declined more in patients than in controls, indicating greater fatigability in ALS. There was a similar decline of voluntary and tetanic force, suggesting that much of the fatigue was not central. Evoked compound muscle action potential amplitudes were preserved during exercise in both groups, indicating no failure of neuromuscular transmission; this result suggests that the source of fatigue was not at the neuromuscular junction or within the muscle membrane. In spite of greater fatigability, changes during exercise in energy metabolites and proton signal intensity tended to be less in ALS patients compared with controls, suggesting impaired muscular activation. We conclude that the greater muscle fatigue in ALS patients results from activation impairment, due in part to alterations distal to the muscle membrane.
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PMID:Physiology of fatigue in amyotrophic lateral sclerosis. 772 63

A 68-year-old man with severe dyspnea was admitted as an emergency case. He had no past history of any respiratory or neuromuscular diseases. Immediately after insufflation of oxygen, respiratory arrest occurred. The blood gas analysis showed hypoxemia and severe hypercapnia (PaO2; 32 mmHg, PaCO2; 127 mmHg). We diagnosed as CO2 narcosis, and he was treated with a respirator in the ICU. He showed nonflaccid bilateral diaphragmatic paralysis and muscle atrophy of the upper extremities. As the EMG showed giant spikes of neurogenic pattern, he was diagnosed as ALS. Weaning from the respirator failed because of his respiratory muscle fatigue. He was given rehabilitation during the day time and ventilatory support with the respirator during the night. We conclude that if we meet with an emergency patient with CO2 narcosis without any pulmonary disorder, we have to suspect neuromuscular diseases, e.q. ALS. In some of such cases, mechanical ventilation supports social rehabilitation.
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PMID:[A case of emergency admission for CO2 narcosis in a patient with amyotrophic lateral sclerosis]. 852 59

The defect of neuromuscular transmission is one of the important signs in ALS. The amplitude of a single motor unit potential from patients with ALS often decrease during tonic voluntary contraction. This phenomenon is closely correlated with fatigue seen in the patient. Overfunctioning of Ach release in the nerve terminal might cause the failure of neuromuscular transmission in ALS. Fasciculations is an another characteristic sign and considered mainly to be peripheral axons in origin. It is postulated that the dysfunction of potassium channel in ALS axons makes the hyperexcitability of the axon membrane, causing fasciculations. Magnetic cortical stimulation sometimes evokes the same potentials as fasciculations, implying the hyperexcitability might be present also in spinal motoneurons or even in pyramidal neurons in ALS. All of these findings lead to the hypothesis that hyperexcitability or overactivity of central and peripheral motoneurons is an essential feature in ALS.
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PMID:[Abnormal hyperexcitability in ALS]. 1037 5

Adult motor neuron disease (amyotrophic lateral sclerosis [ALS]) is a neurodegenerative disorder characterized by loss of motor neurons in the cortex, brain stem, and spinal cord, manifested by upper and lower motor neuron signs and symptoms affecting bulbar, limb, and respiratory musculature. Clinically, the disease course is characterized by progressive weakness, atrophy, spasticity, dysarthria, dysphagia, and respiratory compromise, ultimately resulting in death or mechanical ventilation in the vast majority of patients. Patterns of presentation and pathological features of the disease, along with clinical and electrophysiologic criteria for diagnosis, are discussed in this review. Since 8% to 22% of patients survive more than 10 years without ventilator use, meticulous medical and rehabilitation management is extremely important to ensure optimal health and quality of life in these patients. Major issues in the care of individuals with ALS include weakness and spasticity, impairments in activities of daily living and mobility, communication deficits and dysphagia in those with bulbar involvement, respiratory compromise, fatigue and sleep disorders, pain, and psychosocial distress. Research in ALS changes rapidly, but is currently focused on potential etiologic factors such as glutamate excitotoxicity, role of oxidative stress, autoimmunity to calcium channels, and cytoskeletal abnormalities, as well as related treatment initiatives including glutamate modulators, neurotrophic factors, antioxidants, antiapoptotic factors, and gene therapy. Recently, mutations in the gene encoding Cu/Zn superoxide dismutase were identified in a subset of familial ALS patients. Riluzole, a glutamate antagonist and Na-channel blocker, became the only drug currently approved for treatment of ALS after studies showed a small positive effect on survival. Until a definitive treatment or cure for ALS is found, the multifaceted rehabilitation team approach remains the best hope for improving health and survival in this devastating illness.
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PMID:Evaluation and rehabilitation of patients with adult motor neuron disease. 1045 74

The detection of respiratory muscle weakness in ALS is necessary to plan initiation of noninvasive positive pressure ventilation and begin discussion of advanced directives. The authors measured the erect seated and supine forced vital capacity (FVC) in 38 patients with ALS and 15 controls. The supine FVC is significantly lower and the erect--supine FVC difference is significantly greater in patients with complaints of dyspnea, orthopnea, and daytime fatigue.
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PMID:Postural change of forced vital capacity predicts some respiratory symptoms in ALS. 1146 32

A 60-year-old man who has suffered dysarthria since 1999. He had noticed twitching of right upper extremity and orbicularis oris muscle since August 2000. The bulbar type of amyotrophic lateral sclerosis was diagnosed. He was admitted for evaluation of sleep disorder with respiratory distress on November 20, 2000. Arterial blood gas analysis on admission showed marked hypercapnea (PaCO2:51.6 Torr). Nocturnal hypoxia index, which was calculated using the nocturnal oximetry monitoring, was elevated. Non-invasive positive pressure ventilation started during sleep at night, although it was earlier than to start for mechanical ventilation. After one week, both hypercapnea and his nocturnal hypoxia index, together with symptoms, improved markedly. Respiratory insufficiency due to progressive fatigue of respiratory muscles, such as diaphragm and intercostal muscles, is a major cause of death in amyotrophic lateral sclerosis. In general mechanical ventilation is introduced when marked hypercapnea and dyspnea become clinically overt. However, the exact time to introduce noninvasive methods of ventilatory support for amyotrophic lateral sclerosis has not been established. Based on the observation in this patient, we would suggest that earlier introduction of non-invasive mechanical support for ventilation (nocturnal hypoxia index > 70) would be useful to improve the symptoms and to prolong the life of patients with ALS. The nocturnal hypoxia index is useful to decide the time of the introduction of non-invasive mechanical support for ventilation.
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PMID:[Early treatment with non-invasive positive pressure ventilation a successful case of bulbar type amyotrophic lateral sclerosis]. 1177 29

Twenty-five ALS subjects filled out five questionnaires: the ALS Functional Rating Scale, Multidimensional Fatigue Inventory, multidimensional McGill Quality of Life, Center of Epidemiologic Study--Depression Scale, and the Epworth Sleepiness Scale. Fatigue, depression, and excessive somnolence are more pronounced in ALS subjects than in normal controls. Both fatigue and depression are associated with poorer quality of life in subjects with ALS, and should be treated aggressively.
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PMID:Fatigue and depression are associated with poor quality of life in ALS. 1515 19

Assessment of nonspeech tongue function is common in speech-language pathology. This paper reviews techniques used to determine tongue strength and endurance, and describes a constant-effort task. These techniques are intended to reveal and quantify the presence of weakness or fatigue of the tongue. The consequences of performing these tasks with and without a bite block, used to fix jaw position, are considered. Whether nonspeech tongue impairment is associated with speech dysfunction in Parkinson's disease is another topic of interest. Past studies indicated reduced tongue strength and endurance in Parkinson's disease, but these measures did not correlate with speech measures. It was hypothesized that weakness and fatigue need to be impaired to a "critical" level before speech is perceptibly affected. To examine whether experimentally induced tongue fatigue affects speech, normal speakers performed prolonged strenuous tongue exercise. Speech deteriorated following these exercises. A new investigation examines whether 1 hour of speech-like tongue exercise (rapid syllable repetitions) affects dysarthric speech. Preliminary data from 6 participants with Parkinson's disease, 1 person with bulbar ALS, and 6 neurologically normal control subjects indicate that sentences sound more precise but less natural after the exercises. Surprisingly, results did not differ significantly between the groups. Continued collection of data and refinement of tasks will contribute to our understanding of the potential relationships between weakness, fatigue, and speech.
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PMID:Assessment of tongue weakness and fatigue. 1583 58

Prevalence of malnutrition in ALS ranges between 16 and 53 p. 100. The percentage of loss of weight greater than 10 p. 100 or, in a more inconstant way, body mass index lower than 18.5, are relevant criteria of malnutrition because predictive of survival. Arm muscle circumference and bioelectrical impedance analysis can assess body composition, but their impact on disease progression has not been evaluated. Measurement of serum albumin levels is of no interest. NUTRITIONAL REQUIREMENTS: Considering that energy expenditure is increased 10 to 20 p. cent in the majority of patients, energy needs can be estimated to be approximately 35 kcal/kg/d. In order to limit the accumulation of fat mass in the sub-group of patients with decreased energy expenditure, monitoring of triceps skin fold or impedance could be proposed, but their interest remains to be evaluated. In the absence of available data on protein requirements in ALS, an intake ranging between 1 and 1,5 g/kg/d seems reasonable, knowing that there is a risk of deficiency when intake is less than 1 g/kg/d and that an increase to 1,5 g/kg/d, considered as harmless, could be useful in the event of hypercatabolism. Supplementation with creatine, antioxidants or amino acids has not proven to be effective. These nutrients being provided by a balanced diet, specific supplementations have no proven utility provided that the patient receives sufficient proteins and energy. Systematic supplementation with vitamin D is however warranted to prevent osteoporosis due to the known risk related to a common state of deficiency. RELEVANCE OF GASTROSTOMY: Studies with good methodological quality evaluating percutaneous endoscopic gastrostomy (PEG) in ALS are not available. Because of the impact of malnutrition on survival, PEG must be considered when oral intake becomes insufficient. Retrospective studies suggest that the PEG tube is usually inserted too late during the disease course, minimizing expected benefits. Criteria useful for making the decision to installation a PEG tube should be the subject of randomized controlled studies. Mortality in the month which follows PEG, approximately 10 p. cent, is primarily due to respiratory failure. It occurs more frequently among patients having a forced vital capacity<50 p. cent. To avoid a degradation of pulmonary function in this sub-group of patients, several approaches are suggested in the literature: earlier PEG, peri-operative noninvasive ventilation, and radiological gastrostomy which does not require a general anesthesia. Whatever the technique used for gastrostomy, it should be carried out in an expert centre, because patients with ALS are more exposed to complications than others.
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PMID:[Nutritional approach for patients with amyotrophic lateral sclerosis]. 1712 8

ALS is a progressive, fatal, degenerative motor neuron disease of unknown cause. Although advances in understanding pathophysiology of ALS have stimulated the development of new therapies, most of them remain few efficient or ineffective and the main management of ALS patient, to improve quality of life by alleviating symptoms, is symptomatic treatment. This article discusses the approaches now in use to manage some of the most common symptoms of ALS including the following: spasticity, cramps, pain, laryngospasm, pseudobulbar syndrome, salivation and drooling, sleep disorders and fatigue, constipation and trophic troubles.
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PMID:[Symptomatic treatments in amyotrophic lateral sclerosis]. 1712 16


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