Spinal Muscular Atrophy (SMA) is a motor neuron disease. The motor neurons affect the voluntary muscles that are used for activities such as crawling, walking, head and neck control, and swallowing.
SMA affects muscles throughout the body, although the proximal muscles (those closest to the trunk of one’s body - i.e. shoulders, hips, and back) are often most severely affected. Weakness in the legs is generally greater than in the arms. Sometimes feeding and swallowing can be affected. The tongue may show atrophy, and rippling movements or fine tremors, also called fasciculation. Intellectual activity is normal and it is often observed that patients with SMA are unusually bright and sociable.
Type I SMA is also called Werdnig-Hoffmann Disease. The diagnosis of children with this type is usually made before 6 months of age and in the majority of cases the diagnosis is made before 3 months of age. Some mothers even note decreased movement in of the final months of their pregnancy.
Usually a child with Type I is never able to lift his/her head or accomplish the normal motor skills expected early on in infancy. Swallowing and feeding may be difficult and are usually affected at some point, and the child may show some difficulties managing their own secretions. There is weakness of the intercostal muscles (the muscles between the ribs) that help expand the chest, and the chest is often smaller than usual. The chest may appear concave (sunken in) due to the diaphragmatic (tummy) breathing.
Please bear in mind, that even though the diagnosis is set before the age of 6 months of the child, the course of the disease is not that acute in each patient.
The Diagnosis of Type II SMA is almost always made before 2 years of age, with the majority of cases diagnosed by 15 months. Children with this type may sit unsupported when placed in a seated position, although they are often unable to come to a sitting position without assistance. At some point they may be able to stand. This is accomplished with the aid of assistance or bracing and/or a parapodium/standing frame.
Swallowing problems are not usually characteristic of Type II, but vary from child to child. Some patients may have difficulty eating enough food by mouth to maintain their weight and grow, and a feeding tube may become necessary.
Children with Type II SMA frequently have tongue fasciculations and manifest a fine tremor in the outstretched fingers. Children with Type II also have weak intercostals muscles and are diaphragmatic breathers.
In Type I SMA swallowing and feeding may be difficult as the swallowing muscles are usually affected. Breathing is most often difficult, because the strength of the intercostal muscles is limited. We often see diaphragmatic breathing whereas the chest is sunken in. Because of the increasing overall weakness or because of repeated infections of respiratory system the prognosis is uncertain. In most of the children with Type I death occurs within the age of 2 years. Yet again it is important to remember, that Type I and Type II blend together.
Due to the variability of the possible progression observed in patients with Type II, it is hard to say, how quickly if at all, the weakness will increase in the patient. Some children can learn to walk with a help of a bodice or even they can survive to adulthood. However in others the overall condition worsens due to frequent respiratory system infections e.g. pneumonia. There are many cases, where the initial progressive weakness stabilised or where the period of worsening is taking turn with periods of stabilization. Therefore the age of decease varies. It can occur at the age of 3 like in Type I or then in adulthood.
Although not in all children with Type II the respiratory insufficiency occurs, it is the most common cause of death after pneumonia or other infections of the respiratory system.
Our first reaction, when the doctors told us that we can take our child home, was “home?!” How can they expect us to take home a child with a life threatening disease, when we came in with a healthy child before the determination of diagnosis? It is hard to accept, that with such progress in medicine, only a small help exists. Medicine did not yet find any treatment, therapy or surgical solution for SMA to be cured.
While most children diagnosed with Type I are still infants there are a myriad of things that can be done to assist in the cognitive, physical and emotional health of your child. Using balloons and feathers as toys makes for wonderful stimulation and allows them a feeling of independence and accomplishment. Reaching games are a form of physical or occupational therapy that can be very helpful. Instructions in range of motion and other physical/occupational therapy ideas by a licensed therapist are important no matter how young the child. Your physical/occupational therapist can also suggest ideal seating systems that will be most helpful in the comfort and maximum mobility of your child.
Because a child with SMA Type I has difficulty coughing, contacting a respiratory therapist is very important so you can be instructed in chest physiotherapy (CPT). CPT is a method of clearing the lungs of accumulated mucus by using positioning and clapping on the chest to assist in loosening secretions.
Saliva can settle in the nasopharynx causing a faint gurgling sound. Often the secretions or mucus need to be removed by the use of a suction machine. Blowing raspberries and bubbles encourages respiratory strength.
Water therapy can be very helpful as the buoyancy of the water allows movement of the arms and legs that may otherwise not be there. Be sure that the water temperature is at least 90°F and that the child’s head does not go under the water or into the water. You must watch so that the child has no possibility of aspirating (getting fluid into their lungs).
Children with SMA who have difficulty swallowing are at risk for aspirating when eating. Sometimes the child may aspirate his/her own secretions. The child may choke while eating and may also experience weight loss as swallowing becomes more difficult. Assistive feeding may be necessary. Two possible options are:
It is necessary to monitor the respiratory distress by measuring the amount of oxygen in the organism and determine whether it is needed to supply oxygen from an external source. Respiratory distress can be monitored by measuring the level of oxygen saturation in the blood using a tool called a pulse oximeter. A small clip or tape with a red light and a sensor is placed on the patient’s finger or toe to determine the oxygen saturation.
To help a child with breathing, one can use a ventilator. There are several ways of support ventilation:For long-term ventilation a tracheotomy tube is placed (a tracheotomy is placement of a surgical hole in the neck to the large airway (trachea) that a tube can be inserted). There are several options to consider. Consult your physicians and respiratory therapists or contact Families of SMA for literature.
It is important to understand your rights when it comes to making life-sustaining decisions for your child. Be sure that both parents discuss their feelings about this very delicate topic. It is a decision that cannot be made lightly and all options should be covered. Talking to a counsellor in the department of social services at your hospital may be helpful. Once your decision has been reached be sure that you put it in writing, and that all necessary medical personal and family members are aware of your wishes. This is your decision, one you have reached with great care and anguish, and under no circumstances should you allow others to judge you or place their values upon you. You are never alone. Families of SMA are always just a phone call away.
Raising a child with SMA should be no different than raising a child who is not affected. Do as many things as possible that are age appropriate. Many times this means making adaptations. It is very important that children with SMA are assisted in reaching their utmost potential. It is important to get your child upright at the earliest possible age.
Standing is important in development. It allows for better respiratory function, improved bowel function, and encourages greater mobility. Getting your child in an upright position may sometimes require advocacy on the part of the parents to encourage the physician to write a prescription for standing aids. There are several options to consider when choosing the appropriate standing aid. One option is a standing frame and/or parapodium. For added mobility and independence a standing wheelchair is ideal. A child as young as 13 months can use this. Bracing is also an option. Reciprocating GaitOrthosis (RGO's) and weight bearing knee ankle foot orthoses (KAFO’s) have been found to work for children with Type II, and these children have been able to take some steps.
The use of a light-weight manual wheelchair can be an exciting addition for the SMA child. It can provide mobility, independence and a taste of adventure, while still allowing them to use some of their own strength. However, it should be understood that for true independence and mobility, a power wheelchair is necessary.
Scoliosis (curvature of the spine) occurs at some point in essentially all children with SMA Type I and II and some Type III. The degree of the scoliosis will be a factor in deciding how to treat it. Because scoliosis can restrict breathing and pulmonary function, necessary precautions should be taken early. Options for managing scoliosis are: custom seating systems, seating aids and a body jacket. Later, spinal fusion surgery may need to be considered.
If your child has frequent colds and difficulty coughing you may want to inquire about a cough assist machine. The cough assist machine helps with breathing and avoids stiffness of lungs (The CoughAssist™ achieves this by applying a positive pressure to the airways to inflate the lungs, and then rapidly shifts to negative pressure to pull the air out of the lungs). The CoughAssist™ clears the lungs of secretions. Everyday use of spirometer (device used to measure the amount of air inspired and expired) enables you to measure the lung capacity. When the levels are low, it shows retaining of secretions or higher production of secretion in the airways or building up of infection of respiratory system.
Diet, as with any growing child, is very important. Your child's diet deserves careful consideration. Excessive weight can make mobility more difficult. Constant contact with your physician and a nutritionist is very important in this aspect of care.
Spinal Muscular Atrophy is autosomal recessive disorder (disorder due to a defective gene is on an autosome and the disorder will develop when two chromosomes with a defective gene meet – one from the mother and one from the father), which means that both parents are carriers of the disorder. Both parents have to have corresponding genes and these genes have to be passed on to their child. When the child receives these genes from both parents, it will be affected with SMA. Even though both parents are the carriers, the possibility of carrying over of the genes to the child is 25% or scale 1:4.
Hereditary forms (affecting other members of the family) of spinal muscular atrophy in the older age group can occur as autosomally recessive, as mutations (developed on the base of mutation, where mutation = spontaneously developed error on chromosome) or as autosomally dominant. These disorders, subject to genetic disorders, force us to be very accurate in determining the hereditary way in the given family.
From www.fsma.org