Diaphragm Ultrasound in Patients with Neuromuscular Disorders
Massimo Zambon in Ultrasound of the Diaphragm and the Respiratory Muscles, 2022
Neuromuscular disorders are a group of neurological diseases that can affect the muscles, the neuromuscular junction, the peripheral nerves, and the motor neurons. Respiratory function can be affected progressively in muscular respiratory. The diaphragm is particularly affected in late onset Pompe disease (LOPD). Clinical symptoms of NMD patients with diaphragm dysfunction can be subtle particularly in patients with peripheral skeletal disabilities. Patients may disclose dyspnea, morning headache, fatigue, nocturnal awakenings, and hypersomnia (1). Abnormal sleep disorders are frequent in NMD patients with diaphragm dysfunction (2). Diurnal hypoventilation may occur later with disease progression. Even if the introduction of non-invasive ventilation has improved survival in muscular dystrophy (3,4), NMD exposes patients to a risk of acute respiratory failure (5). The diaphragm is the main inspiratory muscle that accounts for more than 80% of forced vital capacity in healthy persons. An ultrasound is a non-invasive radiological technique that can be used to assess diaphragm morphology and function in neuromuscular disorders. A diaphragm ultrasound can be performed in outclinic patients but also in patients admitted in hospital because of acute respiratory distress.
Clinical and electrodiagnostic evaluations of the peripheral nervous system
James W. Albers, Stanley Berent in Neurobehavioral Toxicology: Neurological and Neuropsychological Perspectives, 2005
The preliminary information obtained from the patient with a suspected neuromuscular disorder is identical to that required for any neurological evaluation, and this information is independent of the cause or distribution of the underlying problem(s), that is, information is derived about the onset and temporal profile of motor, sensory, and autonomic complaints; the type and distribution of paresthesia, hyperesthesia, and hyperpathia; and the distribution of weakness. Industrial and medical histories for toxin or drug exposures are obtained, as is a family history, including questions about pes cavus or hammer toe deformities. The general information also includes questions about social habits, including recreational drug use, as well as antecedent illnesses or symptoms of underlying systemic disease. The following sections highlight the clinical and electrophysiological neuromuscular examinations, assuming that conventional historical and general neurological information is available to the examiner and has resulted in a peripheral nervous system localization.
Myositis
Rajan Madhok, Hilary Capell in The Year in Rheumatic Disorders Volume 4, 2004
BACKGROUND. AS discussed above, diagnostic and classification criteria for the IIM are in need of reassessment and improvement. Electromyography (EMG) and nerve conduction velocity (NCV) studies are useful in the differential diagnosis of a number of neuromuscular disorders. They are especially helpful in distinguishing neuropathies from myopathies and, according to some experts, can help in distinguishing among the myopathies. Nevertheless, false-positive findings are not uncommon, in part due to the subjective nature of the assessment and high interobserver variability. The sensitivity of EMG for the diagnosis of IIM has been estimated to be 80-90%, although this may vary with the stage or severity of the disease and among different muscle groups. In the IIM, NCV are usually normal and the EMG shows a characteristic triad that includes: (i) short, small, low-amplitude polyphasic motor unit potentials; (ii) fibrillation potentials, even at rest; and (iii) bizarre high-frequency repetitive discharges. A new approach that has been suggested to be useful in assessing myopathies is the measurement of muscle-fibre conduction velocity (MFCV). MFCV is an analysis of the propagation velocity of an electrical stimulus along muscle fibres. As both muscle-fibre diameter and sarcolemmal excitability are altered in IIM and influence MFCV, it is reasonable to evaluate MFCV as a way of distinguishing the IIM from other mimics.
Is it accurate to classify ALS as a neuromuscular disorder?
Published in Expert Review of Neurotherapeutics, 2020
Michael A. van Es, H. Stephan Goedee, Henk-Jan Westeneng, Tanja C.W. Nijboer, Leonard H. van den Berg
Diseases of the peripheral nervous system are categorized as neuromuscular diseases. There are over 600 distinct neuromuscular disorders, each with a unique set of signs and symptoms, depending on which part of the peripheral nervous system is (predominantly) affected (Figure 1)[4]. Also, the heterogeneity of underlying causes at specific anatomical sites results in variability in the age of onset (ranging from neonatal to late-onset), rate of progression, and disease severity. Nevertheless, most neuromuscular diseases converge to similar downstream effects, ultimately presenting with muscle weakness and atrophy, sensory disturbances, and/or reduced tendon reflexes. Other features that have been listed in subsets of patients with neuromuscular disorders, include marked bulbar signs, involvement of cranial nerves, and respiratory or cardiac dysfunction[4]. A detailed summary of all neuromuscular disorders falls outside the scope of this article.
Pearson syndrome
Published in Expert Review of Hematology, 2018
Piero Farruggia, Floriana Di Marco, Carlo Dufour
Pregnancy and birth are usually normal.Anemia, usually found at the first blood count, is generally transfusion dependent in the early months of life but transfusion independence is highly frequent at under 3 years of age.High levels of adenosine deaminase are found in about 1/2 of the PS patients.Throughout the course of the disease more than 1/2 of patients develop neurological and neuromuscular disorders.The prognosis remains poor.
Multicenter validation of [18F]-FDG PET and support-vector machine discriminant analysis in automatically classifying patients with amyotrophic lateral sclerosis versus controls
Published in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, 2018
Ludovic D’hulst, Donatienne Van Weehaeghe, Adriano Chiò, Andrea Calvo, Cristina Moglia, Antonio Canosa, Angelina Cistaro, Stefanie Ma Willekens, Joke De Vocht, Philip Van Damme, Marco Pagani, Koen Van Laere
A total of 175 ALS patients (ALS-BE), as previously described (13,14), was divided in two groups (a training set of 70 subjects and a second set of 105 ALS patients for within-center validation). The training set (n = 70; 62.1 ± 12.5 years; 44M/26F) was recruited at the tertiary neuromuscular clinic at the University Hospital Leuven (Belgium) between January 2011 and January 2013, whereas the second set patients (n = 105; 61.7 ± 12.0 years; 74M/31F) was recruited between October 2012 and January 2015. All patients had a negative history of other neurologic disorders, underwent neurological investigation, and were electro physiologically tested by an experienced specialist in neuromuscular disorders. Sixty patients had definite ALS diagnosis, 81 patients probable and 34 patients possible ALS diagnosis, based on both the revised El Escorial and Awaji-Shima criteria. (Table 1). The majority (>90%) of subjects underwent PET imaging within four months after their first visit to clinic (median = 1.2 months, range = 0–17 months). Time from first symptom to PET scan was 15.0 ± 12.3 months.
Related Knowledge Centers
- Autoimmunity
- Degenerative Disease
- Motor Unit
- Muscle Atrophy
- Neuromuscular Junction
- Peripheral Nervous System
- Toxin
- Skeletal Muscle
- Sense
- Genetic Disorder