Erb-Roth myopathy: signs, diagnosis, treatment

Erb-Roth myopathy (the generally accepted scientific name for the disease Erb-Roth limb-girdle myodystrophy) belongs to a group of hereditary neuromuscular diseases. What does this mean? This group of diseases is characterized by genetically determined damage to nerve fibers, skeletal-striated muscles or anterior horns in the spinal cord.

The term “myodystrophy, or muscular dystrophy” is used to refer to a large number of diseases with different clinical pictures, but they are based on a primary lesion of the muscle fiber structure, and not motor neurons. Myodystrophies differ in symptomatic manifestations, timing of disease onset, rate of progression of symptoms, genetic nature and type of inheritance.

Erb-Roth muscular dystrophy is characterized by an autosomal recessive type of inheritance, so the disease manifests itself in children whose parents are carriers of the mutation. Currently, 15 genes have been identified whose mutations lead to the development of this pathology. The gene abnormality leads to disruption of the synthesis of proteins that are part of the structure of muscle cells (myocytes), causing the death of myocytes.

The disease was first described in 1885 by the German neurologist W. Erb. At the same time, V. Roth was studying pathology in Russia.

Symptoms

Symptoms of the disease are initially non-specific and include general weakness and weakness of the back muscles. Gradually the disease progresses. The patient stops holding his back in a normal position, and hyperlordosis develops - hyperextension of the lower back backwards.

The gait changes quite early. It becomes like a “duck” - waddling of the legs due to weakness of the muscles of the thigh and pelvic girdle. Muscle wasting of the upper shoulder girdle develops rapidly. General malnutrition and then muscle atrophy also gradually develop. Sometimes there is pseudohypertrophy of the legs - replacement of muscle mass with fat and connective tissue.

Over time, the patient stops performing many active movements. Getting up becomes significantly more difficult; patients have to get up on all fours and help with their hands when getting up. The patient's face becomes amicable, the eyelids do not close completely, the lips, on the contrary, turn anteriorly and often thicken (tapir lips). The facial expressions of such a patient are sometimes called the face of a myopath.

Sources

1. Grishina D.A., Suponeva N.A., Shvedkov V.V., Belopasova A.V. Hereditary progressive limb-girdle muscular dystrophy type 2A (calpainopathy): review of the literature. Neuromuscular diseases. 2015;5(1):25-34. https://doi.org/10.17650/2222-8721-2015-1-25-34
2. Sharkova I.V., Dadali E.L., Ryzhkova O.P., Evdokimenkov V.N. Comparative analysis of the characteristics of the phenotypes of limb-girdle muscular dystrophies of types 2A and 2I. Neuromuscular diseases. 2013;(2):39-44. https://doi.org/10.17650/2222-8721-2013-0-2-39-44
3. Muscular Dystrophy Association. Limb-Girdle Muscular Dystrophy (LGMD)
4. The Classification, Natural History and Treatment of the Limb Girdle Muscular Dystrophies. Alexander Peter Murphy and Volker Straub (J Neuromuscul Dis. 2015 Jul 22; 2(Suppl 2): ​​S7–S19)
5. Facts about Limb Girdle Muscular Dystrophy (LGMD) at lgmd-info.org
6. 229th ENMC international workshop: Limb girdle muscular dystrophies – Nomenclature and reformed classification Naarden, the Netherlands, 17–19 March 2021. Volker Straub, Alexander Murphy, Bjarne Udd (DOI: https://doi.org/10.1016/j.nmd. 2018.05.007)

Attention

For the site, I select materials from various sources, which I try to check as much as possible for accuracy and scientific significance. I place links to sources in parentheses after paragraphs or at the end of the page/post. However, the information provided cannot be considered an absolutely reliable medical source. Be sure to consult with specialists. I translate English/French texts myself. I am not a doctor or a professional translator. If you find an error, inaccuracy or want to supplement the information, please write to me by email [email protected] When using site materials, be sure to indicate an active link to the source - the site.

Diagnostics

The diagnosis of the disease is usually made quite accurately. When diagnosing Erb-Roth dystrophy, attention is paid to the age at the onset of the disease, heredity, and the rate of progression of the process. A neurological examination reveals a decrease in reflexes up to loss, a decrease in muscle tone, and the presence of joint contractures (due to the uneven process of muscle atrophy).

Contrary to misconceptions, fascicular muscle twitches do not occur. When recording muscle biocurrents, the amplitude, but not the frequency, of discharges decreases. ENMG determines the shortening of the duration of action potentials and the polyphasic nature of the recording.

Biochemically, changes in the activity of creatinine kinase, AST and other enzymes are often detected. Sometimes changes in the composition of blood electrolytes are detected.

The diagnosis is considered reliable when conducting a histological examination of the muscles. The shape and size of muscle fibers change, the perception of their coloring with histological dyes changes, muscles degenerate, and the volume of muscle nuclei increases. Between the muscle fibers fat and connective tissue are determined. In this case, there is no bundle distribution of fibers, characteristic of neurogenic myopathies.

Types of limb-girdle muscular dystrophy

In 2017, a new classification of limb-girdle muscular dystrophy was agreed upon (read the entry for more details).
Genes are codes (or recipes) that cells use to build the various proteins our bodies need.
Genes associated with CMMD encode proteins that are essential for normal muscle function. If one of these genes has a mutation (a defect in the form of missing or incorrect information), the cells cannot produce the proteins to form healthy muscles. Attention! If your medical reports indicate Erb-Roth , then you have not been diagnosed . Achieve an accurate diagnosis with genetic confirmation! This will help you choose the right therapy and prevent or reduce the consequences of the disease.
Additionally: history of studying CPMD. Who are Erb and Roth?

Classifications KPMD 1995/2017

The currently known classification (nomenclature) of KPMD (for example, KPMD 2A, 2B) was developed in 1995. At that time, only a few genes responsible for the occurrence of CMMD were described.

According to the 1995 classification, the subtypes of CMMD are divided into two large groups: CMMD 1 and CMMD 2. CMMD type 1 is inherited in an autosomal dominant manner, i.e. It takes one defective copy of the gene for the disease to occur. CMMD type 2 is inherited in an autosomal recessive manner, in which the disease occurs when both copies of the gene are defective. Each of the subtypes has its own letter. Sometimes limb-girdle muscular dystrophy is called a specific name depending on the damaged protein, for example, LGMD 2A (calpainopathy), LGMD2B (dysferlinopathy). There are other names []. The letter in the 1995 classification was added to the contract for opening the KPMD form [].

Dominantly inherited types of CPMD are less common: about 5-10% of cases of the entire population of CPMD are registered. The worldwide prevalence of CMMD is estimated to be 1 case in 14,500 to 45,000 people. The most common subtype of reported cases is LGMD2A (26.5–30%), followed by LGMD2I (19%), although data varies widely among different populations. Subtypes of CPMD are often grouped based on the protein affected [].

At the moment, many new genes have been discovered, and for CMMD with a recessive type of inheritance there are no longer enough letters in the 1995 classification. In March 2021, an international meeting of CPMD specialists was held in the Netherlands at the European Neuromuscular Center (ENMC) to develop a new classification system (nomenclature) [].

Classification (nomenclature) of KPMD 2021

Below is a table with the new classification (nomenclature) of CPMD, agreed upon at the ENMC meeting in 2017. I also saved the 1995 nomenclature on this page (click to quickly jump to it). There is additional useful information in the old nomenclature (match old names). Someday I’ll make a general table to make it more convenient.

The proposed formula for the names of CPMD subtypes looks like this []:

CMMD (LGMD), type of inheritance “P” - recessive or “D” - dominant (R or D in English), number in order of discovery, damaged protein.

Attention: I have not yet seen the Russian translation of the new classification anywhere, so the translation is speculative.

Classification (nomenclature) KPMD 1995

Below is a table of types from the article “The Classification, Natural History and Treatment of the Limb Girdle Muscular Dystrophies” (Alexander Peter Murphy and Volker Straub). I did not duplicate the sources used by the authors. To view them, go to the site with the original article (the link to the article is attached to its title).

Since the table contains medical terms, I give the wording in English from the original article, and indicate the translation in parentheses. The table contains links to English and Russian Wikipedia (if I found relevant articles) - I linked them for my own convenience. There are no Wiki links in the original article. In many places I doubted the correctness of the translation of protein functions, so in particularly difficult (for me) places I left only the English description. If you know how to correctly translate the names and functions of proteins, or if I translated something incorrectly, please write to me by email.

You should be aware that patients with late-onset Pompe disease are often diagnosed with CPMD. At the same time, enzyme replacement therapy has been developed for Pompe disease. This is why it is extremely important to genetically confirm your type of neuromuscular disease. After all, if a person is misdiagnosed and instead of Pompe disease is given one of the forms of CPMD without genetic confirmation, the patient is deprived of treatment that can support muscle function, and in some cases, partially restore lost strength. To learn how to get tested for Pompe disease, read the entry “Diagnosis of Erb-Roth myopathy? There's no such thing. But there is Pompe disease with enzyme replacement therapy.”

Because the symptoms of Pompe disease are often similar to LGMD, diseases associated with alpha-1,4 glucosidase deficiency (which includes Pompe disease) were even included in the 1995 LGMD nomenclature under the designation LGMD2V. []. However, when revising the nomenclature of CPMD in 2017, Pompe disease was excluded from the limb-girdle muscular dystrophies [].

Treatment

Pathogenetic therapy has not been developed. Treatment is symptomatic and aimed at reducing the rate of progression. B vitamins, vitamin E, ATP, aloe extract intramuscularly, ATP are actively used. The anabolic hormone retabolil was used some time ago, but increased muscle breakdown was often noted. Also used are drugs such as thioctic acid, Riboxin, Actovegin.

An important role is given to non-drug methods of influence. Massage for patients with Erb-Roth dystrophy should be carried out at a light pace, aimed at combating muscle spasms and strengthening muscles. Exercise therapy also plays an important role. Exercise therapy for illness should be moderate but regular, ideally daily. All muscle groups are trained.

Consistency in carrying out preventive measures allows patients to maintain their ability to self-care for a long time. In my practice, I remember a patient who, at the onset of the disease at 25 years old, until she was 60, retained the ability to move independently and self-care, albeit with limitations.

Disease prognosis

Important components of the treatment of this disease are physical therapy and massage.
The rate of progression of Erb-Roth myopathy can vary greatly among different people. As a rule, death occurs from respiratory (congestive pneumonia) or cardiac complications (heart failure, arrhythmia, cardiomyopathy). With mild Erb-Roth myopathy, a person can retain the ability to move and self-care for many years.

For preventive purposes, genetic counseling is used for future parents and exclusion of consanguineous marriages.

Diet

With Erb-Roth muscular dystrophy, it is important to adhere to a special diet. A properly selected diet allows you to stop inflammatory processes in the body, remove toxins and provide tissues with the necessary nutrients. It implies adherence to the following principles:

• complete rejection of fatty, fried, salted and smoked foods;
• use of fresh vegetables and fruits, lean varieties of fish in the diet;
• absence of foods high in gluten and sugar;
• Only goat's milk is allowed to be consumed;
• carbonated drinks and alcohol are prohibited.

In general, such a diet contains the principles of proper nutrition. Therefore, you can stick to it throughout your life without fear of causing significant harm to your health.

Reasons for appearance

This disease occurs as an independent pathology, which is caused by a genetic or hereditary factor. The reason is changes at the gene level in the patient himself or in a parent, from whom the pathology can be passed on to the child.

In 30% of cases, the disorder occurs primarily, in all others there is a hereditary nature of the disease.

Intrauterine genetic developmental disorders that cause the disease can be triggered by:

• unhealthy lifestyle of the mother (addiction to alcohol, smoking, drugs);
• working in hazardous work during pregnancy;
• living in places with poor ecology;
• late birth (over 40 years);
• uncontrolled use of antibiotics;
• prolonged contact with chemicals.

Progressive muscular dystrophy of Erb in the presence of complications becomes fatal for the patient.

The following main deterioration of the condition is distinguished:

• paralysis;
• congestive pneumonia;
• difficulties in motor activity;
• disorders in the respiratory system;
• cardiac dysfunction;
• death.

Principles of supporting the body during muscle dystrophy

Often, patients with Erb's pathology have a reluctance to fight the disease, which negatively affects the body as a whole. As a result of lack of physical activity, the progression of the pathology is aggravated and accelerated. Muscles must receive the required amount of load.

Experts recommend moderate stress on the body, as well as the use of special support bandages and other devices. For muscle dystrophy, going to the pool, yoga and stretching are good options.

Psychological support is a very important stage of patient support. Sometimes the support of family and friends is enough, but in some cases qualified help may be required. It is important for a person with a similar diagnosis to know that he is not alone and that there are people who support him, empathize and are always ready to help.

Treatment of Erb-Roth myopathy with medications

Therapy for muscle dystrophy is a complex and lengthy process. To date, no drugs have been developed that can completely cure the patient. All therapeutic techniques have the goal of improving the patient’s condition and restoring some functions suppressed by pathology.

To stop the progression of dystrophy, the following drugs are used:

1. Corticosteroid drugs.
2. Vitamin B1.
3. Adenosine triphosphate.

In addition, to slow down the development of the pathological process, the implantation of fetal stem cells is used.

Prognosis and complications

There is no precisely established course of muscular dystrophy. In some, myopathy quickly progresses and causes rapid disability. Others with Erb-Roth disease live for several decades and can care for themselves, but have physical limitations.

The severe course and rapid progression of the disease significantly reduces the life expectancy of patients. Death is more often recorded due to complications of myopathy. With Erb-Roth disease, myocardial failure or dystrophy, impaired gas exchange in the lungs, arrhythmia, congestive pneumonia, and other cardiac or respiratory disorders are possible.

Involvement of smooth muscles below the diaphragm impairs gastric motility, intestinal motility, bladder function, and uterine tone. Diseases of the genitourinary system develop, urinary incontinence, chronic constipation, and other disorders of the digestive and pelvic organs appear.

Prevention methods

There is no specific prevention for this disease, since in most cases it is hereditary. However, doctors offer several methods to minimize the risk of its occurrence.

First of all, even at the planning stage, both future parents must undergo a comprehensive examination of the body. As a rule, it also involves genetic testing to identify pathological genes. If necessary, consultation with specialized specialists may be required.

If a pathology is suspected, a study of cellular elements and blood in the fetus is prescribed to identify gene mutations. The procedure is performed early. Based on its results, the doctor offers parents several options for solving the problem.

If the disease manifests itself already at a conscious age, it is necessary to take measures to alleviate the patient’s condition and to prevent the development of possible complications. In this matter, each case is individual. Therefore, there are no universal recommendations.

Forecast

The survival prognosis depends on the type of disease, as well as complications that the pathology can lead to. Among the concomitant diseases and conditions of muscular dystrophy are the following:

• Violation of the heart.
• Curvature of the spinal column.
• Impaired motor activity.
• Decreased thinking abilities of the patient.
• Respiratory dysfunction.

Pathogenesis of the disease

What is muscular dystrophy? It is advisable to consider the causes and effective methods of treatment after studying the pathogenesis of the disease. It begins its development with pathological changes in muscle tissue, which are metabolic and structural in nature. This is myopathy. They arise against the background of mutations in genes. As a result, there is a deficiency or complete cessation of the synthesis of proteins, which are a necessary structural component of myocytes.

The disease may be descending in nature, with weakness observed in the proximal parts of the arms. However, most often it has an ascending type of distribution of muscle changes. As the disease progresses, the volume of muscle fibers decreases. They gradually cease to function fully and are destroyed. In their place, a fat layer is formed. Over time, muscle tissue is completely replaced by fat. The result is immobilization, followed by disability.

Description

Juvenile Erb-Roth myopathy is a disease of genetic origin that can affect children of completely healthy parents. Most often, the pathology begins to progress during adolescence. The vast majority of diagnoses occur between the ages of 14 and 18 years. Erb's pathology is also called tabes muscularis.

The disease was first mentioned in 1884 by the German neurosurgeon Heinrich Erb, which gave the name to the pathology he described.