Spinal muscular atrophy, or SMA as a medical abbreviation, is a hereditary disease that occurs as a result of a mutation in a gene that is involved in the process of human movement. As a result of the disease, the destruction of motor neurons occurs. These neuronal cells are found in the brainstem and spinal cord. Their main purpose is to control the basic movement functions such as pulling, squatting, pushing, breathing, rotation and others.
The disease is of four different types. At the same time, the first types are found in very young patients and the latter types in older people.
It has been established that the younger the patient, the more difficult the spinal muscular atrophy. Such a disease as SMA is serious and requires urgent treatment, especially in children.
Without proper treatment, small patients do not live up to three years due to the fact that they cannot fully breathe.
In this article, we figure out what is spinal muscle atrophy, including factors that provoke its development, types of diseases, symptoms, as well as what treatments a doctor can offer patients.
What is Spinal Muscle Atrophy Definition?
Let’s find out the muscle atrophy definition. Spinal muscular atrophy, or SMA as its medical abbreviation, is a genetic disorder that affects the central and peripheral nervous systems. A lot of nerve cells responsible for the muscles’ work are located in the spinal cord. The disease is called muscular because its main destructive effect is on muscles that do not receive the necessary signals from nerve cells.
Such a disease as SMA is directly linked to the loss of important cells in the nervous system called “motor neurons” in the spinal cord and is referred to as “motor neuron disease.“
The age at which a person may have the first symptoms of the disease is related to the degree of damage to the motor system. Thus, it is worth paying attention that the younger the person who has encountered a similar disease, the worse the consequences can be. Thus, if an infant has this problem, the chance of normal functioning is very low. While adults with this disease have a high chance of high functioning.
We have considered what spinal atrophy is, and now we should explain to you what are the common symptoms.
What are the Common Muscular Atrophy Symptoms?
The symptoms of SMA can be either mild or severe. Among the main muscular atrophy symptoms are:
- Weakness of voluntary muscles, especially those closer to the center of the body, such as the muscles of the shoulders, hips, and upper back;
- Loss of muscle control;
- Deterioration of movement up to immobility.
It must be said that the symptoms of this disease may depend on its type. Some patients with SMA hardly walk and cannot even sit.
What can Cause Spinal Muscular Atrophy Syndrome?
As a rule, the cause of spinal muscular atrophy syndrome is the absence of part of the CMH1 gene, or it is mutated. When a healthy person has the CMH1 protein and is intact, they produce the CMH protein. And motor neurons function precisely due to this protein. Accordingly, if a person does not have this protein or part of a gene, or a mutation of these elements occurs he can get a disease of spinal muscular atrophy. It will lead to a decrease in motor functions.
It is also important to say that a person has CMH2 genes that produce the CMH protein. So, a person can have about eight copies of this gene. In this case, this leads to fewer complications because copies of these genes replace the missing CMH1 protein.
What is the Range of Spinal Muscle Atrophy Types?
In fact, a wide range of types of this disease can be diagnosed in a patient.
So, a patient can have SMA of the following types:
- 1st type, called Werdnig-Hoffman disease or SMA with an infantile onset;
- 2nd type, which is an intermediate form;
- 3rd type, which is called Kugelberg-Welander disease;
- 4th type, which is called adult-onset SMA.
All of these types of diseases are caused by a mutation or absence of part of the CMH1 gene. This can be expressed both in a complex form in the birth of a child with difficulty breathing at birth or in a weak form, which is expressed in mild weakness in an adult.
Let’s take a closer look at each type of disease.
|SMA type 1 (Werdnig-Hoffmann disease or SMA with an infantile onset)||Usually, this form of the disease manifests itself in children who are less than six months old. If the disease has severely damaged the child’s health, he may have restrictions in movement while still in the womb. So, the baby can be born already with contractures and heavy breathing. In this case, without proper treatment, the death of the child occurs about a year after birth. Contact us to get the consultation.
Symptoms of this type in a child can be in the form of:
Children with spinal muscular atrophy type 1 will not be able to sit or stand on their own. And gradually, without treatment, a child with this type of disease dies at the age of 1-2 years. The reason is that he cannot fully breathe on his own, which leads to respiratory failure.
|SMA type 2 (Intermediate form)||This disease usually gives birth to a child between the ages of six months and one and a half years. Although the first symptoms of this disease may be noticeable to parents and doctors much earlier.
Children with spinal muscular atrophy type 2 cannot sit or stand without the help of an adult. Without proper serious treatment, the child will not be able to perform these functions on his own. Also, among the signs of this disease, it can be noted that the child has difficulty breathing, including hyperventilation during sleep. The deterioration of the condition occurs variably without proper treatment.
Children with spinal muscular atrophy type 2 live much longer than children with spinal muscular atrophy type 1. A patient with such a problem can live to adolescence, which is also negligible. If the child receives the necessary treatment, he may experience improvement in motor outcomes.
|SMA type 3 (Kugelberg-Welander disease)||If a child has it, the first signs may be noticeable in babies of the first years. Children can walk without additional help.
Among the other signs of this type include:
Despite the presence of the disease and the manifestation of symptoms, people diagnosed with spinal muscular atrophy type 3 can have approximately the same life expectancy as healthy people. Treatment of this type of disease helps to achieve good results in patients.
|SMA type 4 (or adult-onset SMA)||With this type of disease, symptoms may appear in patients as young as 21 years of age. Among the signs of this type of disease, doctors note the weakness of the proximal muscles of moderate severity and other symptoms that we talked about.|
How is SMA Disease Diagnosed?
Usually, if this disease is suspected, the patient is analyzed to look for mutations or the absence of part of the CMH1 gene. A similar diagnostic method helps to identify whether a given patient is a carrier of a disease such as spinal atrophy of muscle of any type. Also, such an analysis shows whether the patient is a carrier of this disease, which may not be expressed in the patient himself, but be transmitted to children. The analysis performed to diagnose spinal muscular atrophy can show results with an accuracy of up to 95%.
The patient’s CMH1 gene does not have pathologies or the results of the examination. So, diagnoses are not typical for a disease such as spinal muscular atrophy. Then the patient may follow other methods of examination such as:
- Electromyography, which is able to mark the electrical activity of the muscles during their contraction, as well as in a state of immobility;
- Nerve velocity study, which helps measure the ability of a nerve to send electrical signals;
- Muscle biopsy;
- Other blood tests at the discretion of the doctor.
What is the Treatment for SMA?
It must be said that spinal atrophy of a muscle cannot be completely cured. However, in some cases, the right treatment can help the patient survive. In the case of infants, treatment can alleviate the patient’s condition, stop the development of complications of the condition, and help maintain the necessary processes.
As we have said, without treatment, young patients quickly die of respiratory failure. The reason is the younger the patient, the more pronounced the symptoms and the sooner treatment are needed. Consider the treatment options that are used to maintain the necessary functions and increase life expectancy in patients:
- Science has approved nusinersen (Spinraza) as a drug. This drug is given to children by injection into the fluid that is in the spinal cord. This helps increase the production of the full-length CMH protein, which plays a major role in keeping motor neurons functioning. The benefit of this drug is quite large, especially in very young patients.
- In 2019, scientists isolated a gene therapy using the onasemnogene abeparvovec-xioi. This method is used for children with spinal muscular atrophy, whose age is about two years. It delivers a working SMN gene to human motor neurons, improving muscle function, movement, and lifespan.
- Physiotherapy and rehabilitation can also help the patient stop the decline in joint function and slow down the patient’s muscle weakness. A set of exercises designed by a doctor can help reduce the contracture and increase the range of motion, which will favorably affect the patient’s circulatory process.
- Therapy aimed at eliminating problems with speech and swallowing.
- Installation of supports, braces, orthopedic insoles, and wheelchairs can also help the patient begin to move independently.
- The transition to proper nutrition and getting enough calories to maintain normal weight and strength is another important point in the treatment of spinal muscular atrophy in patients.
- Insertion of special swallowing probes for patients who cannot do this on their own.
- Setting up non-invasive ventilation at night can normalize the breathing of patients during sleep.
Lone Star Neurology Clinic is Always Ready to Help Patients Occur Their Disease
If you or your relative has such a problem as spinal muscle atrophy, you must visit a neurologist. We can advise you on our clinic Lone Star Neurology. Call us at (214) 619-1910, and make an appointment.
Our high-quality specialists can help you to diagnose and treat different neurological disorders such as:
- Diabetic neuropathy;
- Peripheral neuropathy
- Alzheimer’s disease;
- Headaches and migraines;
- Parkinson’s disease;
- Multiple sclerosis.
Actually, it is not a complete list of our help. We deal with many diseases. We advise you to go to our website and read in more detail about our offers.
- How do you get spinal muscular atrophy?
A disease such as spinal muscular atrophy is a genetic disease and occurs as a result of a mutation in the CMH1 gene, which is responsible for the patient’s motor activity. The partial absence of this gene or its damage leads to the loss of normal function of movement, and respiration, and can lead to severe complications, especially in small children.
- Is spinal muscular atrophy painful?
The pain that is present in patients with spinal muscular atrophy is comparable to that of osteoarthritis or chronic low back pain. Patients who have received this disease at a sufficiently adult age have a lower tendency to pain than children with the same disease.
- Can you recover from spinal atrophy?
There is no cure for this condition. However, with the help of quality treatment, the patient may experience relief of symptoms, and his life expectancy can be significantly increased. Treatment is especially important for children, without treatment, a small child may not live to be a year old due to respiratory failure.
- What is the life expectancy of someone with spinal muscular atrophy?
Usually, infants with a disease such as spinal muscular atrophy have the first type of the disease and die in the first year of life due to respiratory failure. Children with type 2 or 3 can survive into adolescence or even become full adults with quality treatment. Adults with stage 4 SMA can function normally and live fulfilling lives despite the disease, and their life expectancy is no less than that of healthy individuals.