Rhabdomyolysis – Go big or go home

ObjectiveTo evaluate the occurrence of renal injury in hospitalized patients with the diagnosis of rhabdomyolysis among a series of patients presenting to an urban emergency department.MethodsA retrospective chart review between January 2006 and February 2017 was conducted on patients aged 21–65 years old that were admitted with a diagnosis of Rhabdomyolysis. We included patients with an initial serum creatinine (Cr) level < 1.3 mg/dL and an initial serum creatine phosphokinase (CPK) level > 1000 U/L. We excluded patients with preexisting renal disease, hypertension, diabetes, patients currently on medications in the statin class, patients with muscular dystrophy and neuromuscular disorders.ResultsOne hundred and fifteen patients (100 men, 15 women) were enrolled, with a mean age of 36 years old. The mean CPK at presentation was 18,965 U/L and the highest CPK was 168,300 U/L. The mean Cr upon presentation was 0.95 mg/dL. The average length of stay of our patients was 4.6 days. The longest length of stay was 30 days and the shortest was 1 day. Seven patients had hospital stays longer than 10 days. None of the patients had prolonged admissions due to rhabdomyolysis alone. The patient admitted for 30 days had a protracted admission due to liver failure and sepsis thought to be unrelated to Rhabdomyolysis. No patients that fit our inclusion criteria developed renal insufficiency (Cr > 1.3 mg/dL) or failure regardless of their CPK upon presentation, peak CPK or therapies received during their hospitalization.ConclusionPatients in our data set that presented to the Emergency Department with a CPK of >1000 U/L and a Cr of <1.3 mg/dL that were hospitalized with a diagnosis of rhabdomyolysis are not at risk for developing renal insufficiency or failure if treated promptly with fluid rehydration, regardless of their initial CPK values.     

Musculoskeletal complications of neuromuscular disease in children

A wide variety of neuromuscular diseases affect children, including central nervous system disorders such as cerebral palsy and spinal cord injury; motor neuron disorders such as spinal muscular atrophy; peripheral nerve disorders such as Charcot-Marie-Tooth disease; neuromuscular junction disorders such as congenital myasthenia gravis; and muscle fiber disorders such as Duchenne's muscular dystrophy. Although the origins and clinical syndromes vary significantly, outcomes related to musculoskeletal complications are often shared. The most frequently encountered musculoskeletal complications of neuromuscular disorders in children are scoliosis, bony rotational deformities, and hip dysplasia. Management is often challenging to those who work with children who have neuromuscular disorders.     

Analysis of the nursing role in the care of patients with neuromuscular disorders

The nursing role in neuromuscular disorders has been shown as a promising solution in service organization. However, the role of neuromuscular nurses has scarcely been addressed in the literature. The present evaluation process was geared toward defining nursing role in relation to systematic follow-up of neuromuscular disorders and to assess its theoretical background.     

Diazepam prevents some adverse effects of succinylcholine.

Neuromuscular, circulatory, and adverse effects of intravenous succinylcholine (SCh), mg/kg, were compared in 3 groups of 40 patients each. Group I served as control; group II received diazepam, 0.05 mg/kg, 5 min before SCh; and group III was given d-tubocurarine (d-Tc), 0.05 mg/kg, for pretreatment. Diazepam pretreatment prevented muscle fasciculations, increases in serum potassium (K+) and creatinine phosphokinase (CPK) levels, increased heart rate and arterial pressure, and postoperative myalgia associated with SCh administration. The neuromuscular blocking action of SCh was not affected. Pretreatment with d-Tc did not abolish increases in serum K+ and CPK levels, was associated with a higher incidence of postoperative myalgia, and decreased the onset and magnitude of SCh-induced muscle paralysis. Our data demonstrate that diazepam, a predominant centrally acting muscle relaxant, is more effective than d-Tc in preventing the adverse effects of SCh, a peripherally acting muscle relaxant.     

The changing role of pediatric electrodiagnosis

Electrodiagnosis is one of several useful diagnostic tests in infants and children who have anterior horn cell disease, neuropathy, neuromuscular junction disorders, or myopathy. It is also used for intraoperative monitoring in children. For hypotonic infants and for older children with a nonspecific presentation of weakness, EDX may provide direction for more specific diagnostic testing, such as DNA testing with or without muscle biopsy. Genetic testing has an increasingly important role in the diagnosis of children with neuromuscular disorders. Future improvements in motor unit quantitation, which do not require active patient cooperation and require less time than current methodologies, may make EDX more specific and useful for diagnosing neuromuscular disease in children.     

A practical approach to molecular diagnostic testing in neuromuscular diseases

Molecular diagnosis is an important aspect in the care of patients with neuromuscular disorders. Because of the rapidly evolving nature of the field, the approach to obtaining a molecular diagnosis may be challenging. This article provides a general approach to molecular diagnostic testing while reviewing the principles of genetics and genetic disorders and the indications and limitations of testing methods in common hereditary neuromuscular disorders.     

Genetics of neuromuscular disorders

Neuromuscular disorders affect the peripheral nervous system and muscle. The principle effect of neuromuscular disorders is therefore on the ability to perform voluntary movements. Neuromuscular disorders cause significant incapacity, including, at the most extreme, almost complete paralysis. Neuromuscular diseases include some of the most devastating disorders that afflict mankind, for example motor neuron disease. Neuromuscular diseases have onset any time from in utero until old age. They are most often genetic. The last 25 years has been the golden age of genetics, with the disease genes responsible for many genetic neuromuscular disorders now identified. Neuromuscular disorders may be inherited as autosomal dominant, autosomal recessive, or X-linked traits. They may also result from mutations in mitochondrial DNA or from de novo mutations not present in the peripheral blood DNA of either parent. The high incidence of de novo mutation has been one of the surprises of the recent increase in information about the genetics of neuromuscular disorders. The disease burden imposed on families is enormous including decision making in relation to presymptomatic diagnosis for late onset neurodegenerative disorders and reproductive choices. Diagnostic molecular neurogenetics laboratories have been faced with an ever-increasing range of disease genes that could be tested for and usually a finite budget with which to perform the possible testing. Neurogenetics has moved from one known disease gene, the Duchenne muscular dystrophy gene in July 1987, to hundreds of disease genes in 2011. It can be anticipated that with the advent of next generation sequencing (NGS), most, if not all, causative genes will be identified in the next few years. Any type of mutation possible in human DNA has been shown to cause genetic neuromuscular disorders, including point mutations, small insertions and deletions, large deletions and duplications, repeat expansions or contraction and somatic mosaicism. The diagnostic laboratory therefore has to be capable of a large number of techniques in order to identify the different mutation types and requires highly skilled staff. Mutations causing neuromuscular disorders affect the largest human proteins for example titin and nebulin. Successful molecular diagnosis can make invasive and expensive diagnostic procedures such as muscle biopsy unnecessary. Molecular diagnosis is currently largely based on Sanger sequencing, which at most can sequence a small number of exons in one gene at a time. NGS techniques will facilitate molecular diagnostics, but not for all types of mutations. For example, NGS is not good at identifying repeat expansions or copy number variations. Currently, diagnostic molecular neurogenetics is focused on identifying the causative mutation(s) in a patient. In the future, the focus might move to prevention, by identifying carriers of recessive diseases before they have affected children. The pathobiology of many of the diseases remains obscure, as do factors affecting disease severity. The aim of this review is to describe molecular diagnosis of genetic neuromuscular disorders in the past, the present and speculate on the future.     

The Potential of Disease Management for Neuromuscular Hereditary Disorders

Neuromuscular hereditary disorders require long‐term multidisciplinary rehabilitation management. Although the need for coordinated healthcare management has long been recognized, most neuromuscular disorders are still lacking clinical guidelines about their long‐term management and structured evaluation plan with associated services. One of the most prevalent adult‐onset neuromuscular disorders, myotonic dystrophy type 1, generally presents several comorbidities and a variable clinical picture, making management a constant challenge. This article presents a healthcare follow‐up plan and proposes a nursing case management within a disease management program as an innovative and promising approach. This disease management program and model consists of eight components including population identification processes, evidence‐based practice guidelines, collaborative practice, patient self‐management education, and process outcomes evaluation ( Disease Management Association of America, 2004 ). It is believed to have the potential to significantly improve healthcare management for neuromuscular hereditary disorders and will prove useful to nurses delivering and organizing services for this population.     

Evaluation of the phrenic nerve in patients with neuromuscular disorders

Twenty-six patients suffering from neuromuscular disorders underwent electrodiagnostic studies of the phrenic nerve as well as lung function and fluoroscopic evaluations. Fourteen (53.8%) out of the 26, manifested uni- or bilateral phrenic nerve involvement. Of these, only 5 (35.7%) showed a correlation between clinical complaints of shortness of breath and the pathological findings in the electrodiagnostic studies of the phrenic nerve and in the lung function and fluoroscopic evaluations. Another 5 (35.7%) patients had normal lung function and fluoroscopic evaluations, in spite of complaints of shortness of breath and pathological phrenic nerve conduction findings. It is recommended, therefore, that electrodiagnostic evaluation of both phrenic nerves be part of the evaluation of patients with neuromuscular disorders.     

Muscle ultrasound in children: normal values and application to neuromuscular disorders

In this study, 105 healthy children (45 to 156 months old, 57 girls) were examined using ultrasound (US) imaging to obtain reference values of muscle dimensional and aspect parameters. We measured biceps and quadriceps sizes and subcutaneous tissue thickness. To quantify muscle aspect, we calculated muscle density, inhomogeneity and white-area index by digital image analysis. Age-, weight- and gender-dependencies were discussed. We demonstrated earlier that the complete set of parameters allows for differentiation between myopathies and neuropathies in adults, with high sensitivity. In this study, we investigated if these parameters have additional value in the diagnostic evaluation of 36 children with proven neuromuscular disease (20 Duchenne muscular dystrophy, 16 neuropathies). We found that density analysis provides a sensitive method for distinguishing between healthy children and children with neuromuscular disorders. We have also found that more detailed aspect analysis is necessary to further distinguish between these types of neuromuscular disorders in children. In conclusion, this set of normal muscle parameters can be used to help diagnose neuromuscular disorders in children. It will also facilitate follow-up in disease progression and therapy.     

Serum positive botulism with neuropathic features

A 32-year-old man presented with multiple cranial neuropathies and his serum was positive for botulism type B. However, serial electrodiagnostic studies were consistent with a primarily neuropathic process, such as Fisher syndrome, rather than a neuromuscular junction disorder. Electrodiagnostic study findings in patients with presumed neuromuscular junction disorders may mimic findings suggestive of a neuropathic process, or the bioassay for botulism may be falsely positive in patients with Fisher Syndrome.     

Intensive-care-unit-acquired muscle weakness

Neuromuscular abnormalities culminating in skeletal-muscle weakness occur very commonly in critically ill patients. Intensive-care-unit (ICU) acquired neuromuscular abnormalities are typically divided into 2 discrete classes: polyneuropathy and myopathy. However, it is likely that these 2 entities commonly coexist, with myopathy being the most common cause of weakness. Major risk factors for ICU-acquired neuromuscular abnormalities include sepsis, corticosteroid administration, and hyperglycemia, with other associated factors including neuromuscular blockade and increasing severity of illness. The pathogenesis of these disorders is not well defined, but probably involves inflammatory injury of nerve and/or muscle that is potentiated by functional denervation and corticosteroids. ICU-acquired neuromuscular abnormalities are associated with multiple adverse outcomes, including higher mortality, prolonged duration of mechanical ventilation, and increased length of stay. The only intervention proven to reduce the incidence of ICU-acquired neuromuscular abnormalities is intensive insulin therapy. Additional research is necessary to better delineate the causes and pathogenesis of these disorders and to identify potential preventive and therapeutic strategies. In addition, consensus guidelines for its classification and diagnosis are needed.     

Immunotherapies in neurologic disorders

Therapy for autoimmune demyelinating disorders has evolved rapidly over the past 10 years to include traditional immunosuppressants as well as novel biologicals. Antibody-mediated neuromuscular disorders are treated with therapies that acutely modulate pathogenic antibodies or chronically inhibit the humoral immune response. In other inflammatory autoimmune disorders of the peripheral and central nervous system, corticosteroids, often combined with conventional immunosuppression, and immunomodulatory treatments are used. Because autoimmune neurologic disorders are so diverse, evidence from randomized controlled trials is limited for most of the immunotherapies used in neurology. This review provides an overview of the immunotherapies currently used for neurologic disorders.     

神经肌病的CT研究（附30例分析）

目的 研讨CT对神经肌病的诊断价值。方法 收集经临床检查及肌肉活检证实的神经肌病患30例,正常对照10例,对其骨骼肌的CT表现进行了对照分析。结果 神经肌病的基本表现为肌肉的萎缩、肌肉密度的减低、肌间隙的增宽、选择性受累及真、假性肥大等。结论 CT有利于鉴别诊断神经源性及肌源性疾病,并根据CT表现将肌变性的范围及程度分为4期。     

Classroom Evaluation of the Arlyn Arm Robotic Workstation

High school and junior high school students with neuromuscular weakness and other disorders of the arms evaluated a recently commercialized robotic workstation, the Arlyn Arm, to carry out art projects and science experiments. These tasks were designed for independent execution with the workstation using standard or custom-designed tools. Each task was divided into subtasks, and the execution time of each subtask was determined as a measure of efficiency. Special attention was given to the causes of required experimenter intervention. While subjects easily accomplished some subtasks, others required considerable intervention. Most of these interventions could be avoided by further customizing accessories. It is concluded that the Arlyn Arm workstation could be of considerable benefit in a classroom setting to persons with severe neuromuscular disorders.     

Classroom evaluation of the Arlyn Arm robotic workstation

High school and junior high school students with neuromuscular weakness and other disorders of the arms evaluated a recently commercialized robotic workstation, the Arlyn Arm, to carry out art projects and science experiments. These tasks were designed for independent execution with the workstation using standard or custom-designed tools. Each task was divided into subtasks, and the execution time of each subtask was determined as a measure of efficiency. Special attention was given to the causes of required experimenter intervention. While subjects easily accomplished some subtasks, others required considerable intervention. Most of these interventions could be avoided by further customizing accessories. It is concluded that the Arlyn Arm workstation could be of considerable benefit in a classroom setting to persons with severe neuromuscular disorders.     

Mechanisms of ventilator dependence in children with neuromuscular and respiratory control disorders identified by monitoring diaphragm electrical activity

Objectives

To report on the monitoring of diaphragm electrical activity (Edi) using neurally adjusted ventilator assist (NAVA) technology to investigate the mechanisms of ventilator dependence in children with neuromuscular and respiratory control disorders.

Patients and methods

Using NAVA technology, electrical activity of the diaphragm (Edi) was monitored at the lowest achievable level of respiratory support in six ventilator-dependent patients with neuromuscular and respiratory control disorders, aged 6?weeks to 12?years, admitted to a tertiary paediatric intensive care unit between 2009 and 2011.

Results

Edi monitoring identified markedly abnormal respiratory dynamic patterns that were not always apparent clinically. These were associated with disorders of central respiratory control, muscle weakness and diaphragm pathology.

Conclusions

Edi monitoring using NAVA technology is a valuable, minimally invasive, diagnostic adjunct in children with neuromuscular and respiratory control disorders who are ventilator-dependent.     

Echocardiography in storage and neuromuscular disorders

Storage disorders and neuromuscular disorders may lead to cardiac involvement which can be visualized by echocardiography. In storage disorders like hypothyroidism, haemochromatosis, amyloidosis, mucopolysaccharidosis and Fabry's disease, myocardial thickening and systolic dysfunction can be found. In amyloidosis, atrial enlargement and abnormal texture of the myocardium are additional findings. In advanced haemochromatosis all cardiac chambers may be dilated. In hypothyroidism and amyloidosis, a pericardial effusion can be present. In haemochromatosis and amyloidosis, a restrictive filling pattern may be detected using Doppler-sonography. Mucopolysaccharidosis and Gaucher's disease may lead to aortic and mitral stenosis. In neuromuscular disorders like glycogenosis, mitochondriopathy and myotonic dystrophy, myocardial thickening and systolic dysfunction are found, in spinal muscular atrophy myocardial thickening and in muscular dystrophy Becker/Duchenne systolic dysfunction. An abnormal myocardial texture may be present in glycogenosis, isolated left ventricular abnormal trabeculation (ILVAT) in mitochondriopathy, myotonic dystrophy and muscular dystrophy Becker/Duchenne. Using Doppler-sonography an impaired relaxation of the left ventricle may be detected in mitochondriopathy, myotonic dystrophy and spinal muscular atrophy. Most of these echocardiographic findings are unspecific and may be overlooked, especially if the storage or neuromuscular disorder is yet unknown. Establishing a correct diagnosis is important, since healing or functional improvement is possible in many of these disorders.     

Neuromuscular disorders in the intensive care unit

Neuromuscular disorders encountered in the ICU can be categorized as muscular diseases that lead to ICU admission and those that are acquired in the ICU. This article discusses three neuromuscular disorders can lead to ICU admission and have a putative immune-mediated pathogenesis: the Guillian-Barré syndrome, myasthenia gravis, and dermatomyositis/polymyositis. It also reviews critical care polyneuropathy and ICU acquired myopathy, two disorders that, alone or in combination, are responsible for nearly all cases of severe ICU acquired muscle weakness.