Spinal Muscular Atrophy - SMA
definition
Spinal muscular atrophy (SMA) becomes the nerve-damaging diseases of the central nervous system (Brain and spinal cord) and is inheritable.
In its course, nerve cells and the muscles they innervate are damaged. The disease is kinda rare and shows a great variability. It can occur in the first few months of life as well as in adulthood.
Basically, there is one with the disease Weakening and regression of the muscles, which is why the disease is popularly known as "muscular dystrophy" referred to as.
to form
Basically are two forms to distinguish, namely the non-proximal muscular atrophy and the proximal muscular atrophies.
In the case of proximal muscular atrophies, the disease begins on the close to the hull (proximal) Muscle groups, for example in the area of the thigh and the pelvic and hip muscles.
The Non-proximal muscular atrophies are very rare and initially usually affect the muscles of the feet and hands or the muscles of the shoulders and lower legs. In addition, some rare forms are known that are associated with various functional restrictions.
Types of spinal muscular atrophy
The proximal muscular atrophies can be in 4 different types subdivide. These differ in terms of the onset of the disease, the learning of muscular skills and possible life expectancy.
Type I (Werdnig - Hoffmann = acute infantile SMA)
The type I of the SMA is Beginning the disease usually before the age of 6 months. For example, children with Type I cannot hold their heads on their own. Free sitting can never be learned and the Tod occurs within the first months of life a. Reasons for the rapid death can be infections or paralysis of the respiratory muscles.
Characteristic symptoms are pronounced muscle weakness, missing or decreased muscle reflexes and muscle twitchingn. The affected patient has good mental abilities.
Type II = intermediate type = chronic infantile SMA
The onset of the disease is type II within the first 18 months of life. The muscle wasting progresses more slowly here than in type I. Free sitting can be learned, free walking is not possible.
It is not uncommon for the muscles to be shortened considerably (Contractures) as well as changes in the shape of the spine (e.g. a Scoliosis). A Survive into adulthood is indeed possible, but must be with a decreased life expectancy be expected.
Type III = Kugelberg –Welander = juvenile SMA
This is where the disease begins often after the age of 2. Type III shows a significantly milder course. At the beginning there are above all one Poor gait and a Decrease in muscle reflexes to observe. Life expectancy is only slightly reduced.
Type IV = adult SMA
Type IV begins from the age of 30 and here the Get the ability to walk. The course and progression of the disease are very variable and can affect different muscle groups. Life expectancy is to be regarded as normal.
causes
The main cause of SMA is one progressive damage and destruction of specific nerve cells in the spinal cord (Motor neurons). These are responsible for the control and regulation of the muscles. Thus can Impulses from the brain no longer passed on to the corresponding muscles become.
This leads to a weakening and regression (atrophy) of the affected muscles.
The reason for the destruction of nerve cells lies in the change (mutation) of an important gene (SMN gene) in the genome (DNA). Under normal circumstances, this gene produces specific proteins that are supposed to protect the nerve cells from damage.
Is Spinal Muscular Atrophy Hereditary?
For the inheritance of the disease is crucial, whether the changed gene is on both hereditary carriers (Chromosomes) is present or whether the sole presence on one of the two hereditary carriers is sufficient to pass the disease on to the offspring. Many people carry a defective gene, but are not affected by the disease themselves. The genetic defect is compensated for by a second, intact gene copy on the hereditary carriers. The disease only emerges when a child receives the modified gene from both parents.
Concomitant symptoms
In addition to weakening and degradation of the muscles, paralysis (Paresis), decreased muscle tension and a decrease in muscle strength are among the accompanying symptoms. If nerves in the head area (cranial nerves) are also affected, this leads to an impairment in chewing, swallowing and speaking.
Fasciculations, i.e. involuntary twitching of the muscles, can also occur.
At the same time, pain can occur in the affected muscle groups.
If the respiratory muscles are damaged, shortness of breath occurs as an accompanying symptom. Problems with sight or hearing and a decrease in mental abilities are usually not observed.
Affected patients show severe restrictions of movement due to weakened leg, trunk and arm muscles. Changes in the shape of the spine also lead to restricted mobility.
You can learn more about other causes of this here Muscle twitching all over your body
diagnosis
First there is the thorough physical and neurological examination of the patient in the foreground. Various tests should be carried out to determine muscle strength, paying attention to the regression of certain muscle groups and changes in muscle reflexes. Various examinations are available to back up the diagnosis.
The function of nerve cells can be controlled by a Measurement of nerve conduction velocity be checked. The Determination of electrical muscle activity can provide information about the state of excitement of the muscles. A specific blood test can be used to detect genetic changes in the genetic make-up. Muscle reflexes can be triggered and checked by stimulating the respective muscles. For this purpose, a reflex hammer is used to tap lightly on special tendons, for example in the lower area of the kneecap.
Treatment / therapy
Treatment for spinal muscular atrophy is very difficult and complex, there one causal treatment not possible is. Therefore, the focus is primarily on one Improvement and maintenance of previous muscular abilities. If pain occurs, it should be alleviated and possibly in a special way Pain therapy be treated.
The greatest success of treatment is achieved through a Combination of treatments in a wide range of disciplines. These include the physical therapy, the Speech therapy and the Pain therapy. Through physiotherapy, the muscles can be strengthened by means of specific exercises and the use of devices for nerve and muscle stimulation. At the same time, the aim is to improve endurance. Speech therapy encourages children to learn to speak, but adults also benefit from speech therapy exercises. The targeted use of the respiratory muscles as well as the chewing and swallowing muscles is also trained.
Pain therapy should be carried out as an accompanying form of therapy. For very severe pain can a Treatment with medication may be necessary. In addition, special breathing and relaxation exercises are taught that can be used in the event of pain. All forms of treatment or therapies should carried out regularly and consistently become.
Operations, especially in the area of the spine, can be useful to improve mobility. To Support in everyday life aids such as orthopedic shoes, walking and standing aids, seat shells, wheelchairs or stair lifts can be used.
If you have difficulty breathing can be a nocturnal Ventilation be used with the help of face masks (breathing masks). Which aids are useful for the patient must be in Consultation with the attending doctors and therapists to be decided.
forecast
The spinal muscular atrophy is not curable. The prognosis depends on the type of disease. The course of the disease can be slowed down and the quality of life improved by means of different forms of treatment. There are currently no effective drugs, but drug treatment is still the subject of medical research.
Life expectancy
Life expectancy depends on the severity, the course and the type of disease. The later the disease occurs, the higher the life expectancy. With a mild course, life into adulthood can be achieved. To maintain mobility, a consistent, regular training of the muscles and the body.
