Motor neurone disease presenting as respiratory failure

Diagnostic delay in amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease, and the time from symptom onset to diagnosis remains long. With the advent of disease-modifying treatments, the need to identify and diagnose ALS in a timely fashion has never been greater.

METHODS

We reviewed the literature to define the severity of ALS diagnostic delay, the various factors that contribute to this delay (including patient and physician factors), and the role that site of symptom onset plays in a patient's diagnostic journey.

RESULTS

Diagnostic delay is influenced by general practitioners' lack of recognition of ALS due to disease rarity and heterogenous presentations. As a result, patients are referred to non-neurologists, have unnecessary diagnostic testing, and may ultimately be misdiagnosed. Patient factors include their illness behavior-which impacts diagnostic delay-and their site of symptom onset. Limb-onset patients have the greatest diagnostic delay because they are frequently misdiagnosed with degenerative spine disease or peripheral neuropathy.

CONCLUSION

Prompt ALS diagnosis results in more effective clinical management, with earlier access to disease-modifying therapies, multidisciplinary care, and, if desired, clinical trial involvement. Due to lack of commercially available ALS biomarkers, alternative strategies to identify and triage patients who likely have ALS must be employed. Several diagnostic tools have been developed to encourage general practitioners to consider ALS and make an urgent referral to ALS specialists, bypassing unnecessary referrals to non-neurologists and unnecessary diagnostic workup.

A Rare Case of Amyotrophic Lateral Sclerosis With Asymmetrical Phrenic Nerve Lesion Presenting With Acute Respiratory Failure as an Initial Manifestation

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that causes muscle weakness, disability, and eventually, death. Respiratory failure is the leading cause of death in ALS. It is common in the advanced stages of the disease. However, acute respiratory failure is a presenting symptom in only a small number of patients, such as in our case. Here, we present the case of a 54-year-old woman with ALS presenting with respiratory failure due to unilateral diaphragm paralysis as the first manifestation. Although rare, respiratory muscle function failure can be the first symptom of motor neuron disease. Therefore, a motor neuron disease such as ALS, which leads to respiratory muscle weakness and diaphragm paralysis, should be considered in cases of unexplained acute respiratory failure.

Respiratory Involvement in Patients with Neuromuscular Diseases: A Narrative Review

Respiratory muscle weakness is a major cause of morbidity and mortality in patients with neuromuscular diseases (NMDs). Respiratory involvement in NMDs can manifest broadly, ranging from milder insufficiency that may affect only sleep initially to severe insufficiency that can be life threatening. Patients with neuromuscular diseases exhibit very often sleep-disordered breathing, which is frequently overlooked until symptoms become more severe leading to irreversible respiratory failure necessitating noninvasive ventilation (NIV) or even tracheostomy. Close monitoring of respiratory function and sleep evaluation is currently the standard of care. Early recognition of sleep disturbances and initiation of NIV can improve the quality of life and prolong survival. This review discusses the respiratory impairment during sleep in patients with NMDs, the diagnostic tools available for early recognition of sleep-disordered breathing and the therapeutic options available for overall respiratory management of patients with NMDs.

Motor Neuron Disease Presenting With Acute Respiratory Failure: A Case Study

Motor neuron diseases (MNDs) refer to a heterogeneous group of progressive neurologic disorders caused by degeneration of motor neurons. The diseases affect either the upper motor neurons, lower motor neurons, or both, and are characterized by weakness, atrophy, fasciculation, spasticity, and respiratory failure. We report a case of a 61-year-old male patient with no past history of cardiovascular or pulmonary disease, who presented with only dyspnea, and no indication of any other symptom such as muscle weakness, atrophy, or bulbar dysfunction. Neuromuscular conduction study, including a study of the phrenic nerve, confirmed the diagnosis of MND. The patient greatly improved giving respiratory assistance at night, using a noninvasive ventilator. This case indicates that MNDs should be considered as differential diagnoses for patients showing acute respiratory failure of unknown causes. This report will aid in the prompt diagnosis and treatment of MNDs.

Amyotrophic Lateral Sclerosis Presenting Respiratory Failure as the Sole Initial Manifestation

It is rare that amyotrophic lateral sclerosis (ALS) presents with respiratory failure as the sole initial manifestation. A 72-year-old man with mild chronic obstructive pulmonary disease developed exertional dyspnea for 13 months. He then progressed to limb weakness that led to the diagnosis of ALS. Although rare, ALS can present with respiratory failure as the sole initial manifestation more than 1 year prior to limb weakness.

Survival and quality of life after tracheostomy for acute respiratory failure in patients with amyotrophic lateral sclerosis

BACKGROUND

Acute respiratory failure (ARF) is a common event in the advanced stage of amyotrophic lateral sclerosis (ALS) and may be rarely a presenting symptom. Frequently, such patients require intubation and mechanical ventilation (MV) and, in a large proportion, receive tracheostomy, as a consequence of weaning failure. In our study, we investigated postdischarge survival and quality of life (QoL) after tracheostomy for ARF in patients with ALS.

METHODS

DESIGN

This study is a retrospective chart review combined with prospective evaluation of QoL and degree of depression.

SETTING

The study was conducted in an adult, respiratory intensive care unit in a university hospital.

PATIENTS

Amyotrophic lateral sclerosis patients with tracheostomy for ARF between January 1, 1995 and April 30, 2008 were investigated.

INTERVENTION AND MEASUREMENTS

(a) A retrospective chart review was used and (b) prospective administration of the 11-item short-form Life Satisfaction Index (LSI-11) and Beck Depression Inventory (BDI) questionnaires to survivors, at least 1 month after discharge from hospital, was performed.

RESULTS

Sixty patients were studied retrospectively. None of the patients died in the hospital after tracheostomy. Forty-two patients (70%) were discharged completely MV dependent, and 17 patients (28.3%) were partially MV dependent. One patient (1.6%) was liberated from MV. The median survival after tracheostomy was 21 months (range, 0-155 months). The survival rate was 65% by 1 year and 45% by 2 years after tracheostomy. Survival was significantly shorter in patients older than 60 years at tracheostomy, with a hazard ratio of dying of 2.1 (95% confidence interval, 1.1-3.9). All 13 survivors completed the LSI-11 and BDI. The mean (SD) cumulative score on the LSI-11 was 9.3 (3.6; range, 0-22; higher values indicating better QoL), similar to that obtained from a control group consisting of individuals with ALS who had not received tracheostomy (9.3 ± 4.3) and to that reported for persons in the general population. Only 15% of the tracheostomized patients (2/13) were severely depressed, according to BDI; 11 of 13 patients reported a positive view of tracheostomy and said that they would want to undergo this procedure if they could make the decision again.

CONCLUSIONS

Patients with ALS have a high chance of long-term survival after tracheostomy for ARF. Although administered at the time of a respiratory crisis without being discussed in advance, tracheostomy shows good acceptance and results in acceptable QoL.

Patterns of mortality in patients with motor neurone disease

OBJECTIVE

Motor neurone disease (MND) is a rapidly fatal condition with survival of less than 4 years. Patients can deteriorate quickly in the preterminal stages resulting in inappropriate resuscitation or admission to intensive care units (ICU) or accident and emergency (A & E).

MATERIAL AND METHODS

We looked at patterns of mortality with emphasis on the place of death. A retrospective study was performed of all patients attending an MND clinic, who had died within a 10-year period.

RESULTS

Of 179 patients (63 female), 81 patients (45%) died at home, in a hospice or in a nursing home. Sixty-five patients (36%) died in hospital (11 in ICU or A & E). Nine of the latter were previously known to have MND and six admissions were probably avoidable. Most ward patients died of respiratory causes and were treated conservatively.

CONCLUSION

The proportion of patients dying in A & E or ICU was small but could have been reduced further. A number of those who died on the wards could probably have been managed conservatively at home. Older patients and those with bulbar disease had a poorer prognosis.

Motor neuron disease presenting with respiratory failure

Respiratory failure accounts for the majority of deaths in amyotrophic lateral sclerosis (ALS) but only rarely is ALS diagnosed on the basis of respiratory insufficiency. We report four ALS patients presenting with acute respiratory failure. In three patients we have performed EMG needle examination of both hemidiaphragms which showed severe denervation. We reviewed 25 patients previously described presenting with respiratory failure. Almost all patients showed upper limbs weakness and diaphragm involvement; few patients had bulbar dysfunction. The prognosis of these patients is not always in permanent ventilator dependence. Rapidly progressive ventilatory failure may be a striking initial sign of ALS; the main reason is a weakened diaphragm. There are possibilities of significant improvement after a period of rest with ventilatory assistance. In the initial phase of the disease, bulbar dysfunction is not the more common reason of acute respiratory failure.

Motor neuron disease presenting as acute respiratory failure: a clinical and pathological study

Respiratory failure is rarely a presenting symptom of motor neuron disease. Seven patients with motor neuron disease who presented with acute respiratory failure of unknown cause and required mechanical ventilation were studied. They all had symptoms and signs suggestive of diaphragmatic weakness. Respiratory involvement seemed disproportionately severe, as six were ambulatory and only three noted limb weakness. Only one had tongue weakness and none had swallowing difficulty. Electrophysiological studies showed widespread denervation and, in particular, diaphragmatic involvement to explain the severe respiratory failure. Weaning from the ventilator was unsuccessful in all cases. The four patients examined at necropsy showed severe loss of anterior horns cells in the cervical cord, with only minimal upper motor neuron involvement. Motor neuron disease should be recognised as a cause of acute respiratory failure, secondary to diaphragmatic paralysis from involvement of phrenic motor neurons.

Pulmonary Manifestations of Neurological Disease

Breathing is a complicated act that requires sophisticated control mechanisms. The nervous system coordinates 3 fundamentally important components of respiration. The central nervous system has a central pattern generator that, along with appropriate feedback mechanisms, establishes both the resiratory rate and the depth of respirations. The peripheral nervous system facilitates transmission of these respiratory commands to the ventilatory muscles. The nervous system also contributes to the control of airway size. Laryngeal function is coordinated with inspiration, and local nerves in the lung have a major role in determining bronchial patency. Finally, the nervous system acts in incompletely understood ways to regulate perfusion of the lungs and to match local pulmonary blood flow with ventilation. Failure of the nervous system to adequately control these 3 different aspects of respiration may result in lifethreatening illness. Understanding how the nervous system affects control of ventilation, airway patency, and pulmonary perfusion therefore will enable intensivists to recognize and manage the pulmonary complications of neurological disease.

Effects of alterations in pulmonary function and sleep variables on survival in patients with amyotrophic lateral sclerosis

Breathing abnormalities and nocturnal hypoventilation occur in patients with amyotrophic lateral sclerosis (ALS). A prospective study was undertaken to determine the relationship of pulmonary function test abnormalities with quality of sleep and survival in 21 patients with ALS. Results of spirometry including determination of maximal respiratory pressures and arterial blood gases were compared with several formal polysomnographic variables and then also with 18-month survival. The patients had mild to moderate pulmonary function deficits, but the quality of sleep was best related to age (mean age, 58.5 years). The results of pulmonary function tests and arterial blood gas measurements did not correlate well with the presence of nocturnal breathing events or survival time, but the maximal inspiratory pressure was 86% sensitive for predicting the presence of a nocturnal oxygen saturation nadir of 80% or less and 100% sensitive for predicting 18-month survival. Although obstructive breathing events occurred, the primary explanation for the decline in nocturnal oxygen saturation was hypoventilation. We conclude that routine pulmonary function tests may be useful for screening for reductions in nocturnal oxygen saturation and also may have prognostic value. Further studies may determine whether treatment of nocturnal hypoventilation will have an effect on survival in patients with ALS who have breathing impairment.

[Diaphragmatic paralysis disclosed by acute respiratory failure. Apropos of a case of amyotrophic lateral sclerosis and review of the literature]

A case of acute respiratory failure revealing amyotrophic lateral sclerosis is reported. The other neurological diseases with diaphragmatic paralysis are recalled.