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SMA stands for Spinal Muscular Atrophy, a genetic disease that is currently incurable and often fatal. One person in every forty is a carrier of the defective gene that causes SMA and if both parents are a carrier, their child has a 1 in 4 chance of having the disease. This would usually be due to the SMN1 (Survival of Motor Neuron) gene, on Chromosome 5, being "altered" or missing altogether.
The absence or abnormality of the SMN1 gene results in production of low levels of the SMN protein which is essential for the survival of motor neurons. SMA affects these motor neurons in the spinal cord, which are called anterior horns cells. Messages travel from the brain, down the spinal cord, through these horn cells and along motor neurons to the muscles, which are then told to move. In a person with SMA, these messages cannot get through as they should as the anterior horn cells cannot provide an effective link between the brain and the muscles. This means the ability to control the muscles gets less and less to the point where they get weak and waste away. In general the higher the level of SMN protein and later onset of symptoms the less severe the SMA is.
There are around 100 new SMA cases each year in the UK alone, and approximately 1 in 6,500 children are affected. SMA is autosomal recessive which means for a child to be affected BOTH parents must be a carrier of the faulty gene.
SMA Type 1, also known as severe Infantile SMA and Werdnigg Hoffman Disease, is the most severe form of the disease and is generally picked up by the time a child reaches 6 months old. It is also the biggest genetic killer of under 2's in the UK. Although a life expectancy of 2 years can be given, around 80% of babies die before their first birthday. A common cold can easily turn into pneumonia, this usually takes the lives of these babies, along with respiratory failure. Muscle weakness can result in problems with feeding, swallowing, breathing and moving. Children with this SMA are usually very floppy and this can be evident within a few weeks of birth. Many mothers recall their baby being less active in pregnancy.
There is significant weakness of the neck which makes it difficult for a child to hold its head up. Children with Type 1 are unable to sit unsupported and have difficulty in rolling over. Weakness in the chest muscle can be very noticeable by watching how the child breathes, many appear to breathe from their tummy rather than from their chest. Another noticeable sign is tongue fasciculations (flickering), although this can be so slight that a parent wouldn't notice it until they made a conscious effort to look for it as a symptom. Other possible symptoms include; recurrent chest infections, having a weak cry or cough, and having sweaty hands. Constipation can be a common problem along with excess drooling (secretions)
Although children with SMA have limited movement, their brains are completely unaffected and they communicate through their big beautiful eyes and beaming smiles. They are very alert and seem to make up for their physical disabilities with their facial expressions, and they love to play just like any other child. Playing includes sensory toys that are lightweight, brightly coloured and much easier to hold than many other toys. Looking at toys with bright lights and watching television programs are also among favourite activities. Babies can be sat up at a good position in a bean bag, a 30 to 40 degree angle seems the be the best position for most. This position allows them to look around freely and sit up enough to play with toys on an arch above them, whilst being able to breathe more easily. We have a variety of toys that may be available for loan.
Here is a short list of typical signs and symptoms of SMA Type 1:
These symptoms can vary in severity depending how advanced the SMA is in each child, some may not show up till later. Many of the symptoms listed above are also symptoms of other diseases so do not panic straight away if a child in your family shows many of these signs. If you are worried that a member of your family may have SMA, please visit the ACT for SMA contact page and get in touch to explain your concerns click here, or phone the ACT for SMA freephone number 0800 23 43 762. Although they do not have any medical training they can give you their opinion based on past experience and also offer advice on the best way to look into things further.
Although research into SMA is progressing everyday there is currently no known cure. There are, however, lots of things that can be done to help make life more comfortable and enjoyable;
Water Therapy
Water therapy is very good for SMA babies. The buoyancy of the water allows them to move their arms and legs freely which can be very enjoyable, however, extra care must be taken to ensure the child does not aspirate on the water.
Physiotherapy
Physiotherapy can help to shift secretions off the baby's chest. The exercises that are done are very important as they help to reduce the effects of chest infections. Also exercises on the arms and legs can help improve circulation which is important because of the lack of movement. Babies positions should also be changed regularly to help with their circulation.
Tube Feeding
Because babies are at risk of aspirating, due to the difficulty in swallowing, feeding may have to be done via a NG tube of a G tube. An NG tube is passed through the childs nose and goes down into the stomach, whereas a G tube is surgically placed through the skin and directly into the childs stomach. By feeding this way you can be sure of exactly what your baby is getting and massively reduce the risk of baby aspirating into their lungs.
Oxygen
There may become a time when oxygen is needed. This could just be at night time, or it could be permanent. The hospital will arrange, if needed, for oxygen to be installed in your home. You will also be provided with smaller oxygen bottles to allow freedom to go out as you like.
Suction
If your baby is in hospital and it is felt there is a need for suctioning this will be done by the physiotherapist or nurses using a suction machine. A small tube is passed through the nose which then suctions secretions off the chest. It is possible to have a portable suction machine for use within the home but it is very important that this is used to remove secretions from within the mouth only.
SMA Type 2, otherwise known as Intermediate SMA, is usually diagnosed before the age of 2. Every child is different and so lifespan can vary greatly from early childhood through to adulthood dependant of severity, but weakness does increase over time. There is a generalised weakness of muscles with the proximal muscles (those closest to the body) usually being more affected. The legs tend to be more impaired than the arms. Children with SMA Type 2 can sit unsupported and some are able to crawl and stand, but as the child grows these abilities can reduce over time as the weakness to the muscles in the legs and trunk become more apparent. Children with SMA Type 2 are often unable to walk.
The muscles of the chest wall can be affected causing poor breathing function and susceptibility to respiratory infections. Although feeding and swallowing problems are not common they are possible later on. tongue fasciculations are less often found in Type 2 children, but a fine tremor may be seen in outstretched fingers.Type 2 children often have above average intelligence and should be encouraged to reach their upmost potential, they are not mentally affected in anyway and are very bright and alert. Their physical growth develops at a normal pace though scoliosis (curvature of the spine) can become a big problem, especially when wheelchair bound. This is caused by a weakness in the muscles supporting the bones of the spinal column. As this becomes worse it can cause problems with breathing and may be uncomfortable. A spinal fusion surgery may need to be considered. As well as scoliosis some children suffer from deformities to their hands and feet. Where joints are affected this can result in reduced movement of the limbs. Motorised wheelchairs can be considered as early as the age of 3, until then an appropriate buggy should be used.
Physiotherapy is very important to improve good posture, this will enable the child to breathe much easier and exercises will also help to maintain muscle strength. Respiratory exercises and breathing techniques may help to reduce the effects of chest infections. Swimming is a very good form of exercise that enables the child to move all limbs with ease.
SMA Type 3
SMA Type 3, also known as Mild SMA and Kugelberg-Welander Disease, is usually diagnosed between 18 months and early adolescence. This is the mildest form of child onset SMA and prognosis is very good with people living a typically normal life span, however, weakness gets progressively worse over time. They can stand and walk at the beginning but usually with difficulty. Balance and climbing stairs can both be problems, and getting from sitting to standing may prove difficult. They are usually wheelchair bound in time.
Tongue fasciculations are rarely seen in SMA Type 3 patients but a fine tremor may be seen in outstretched fingers. Respiratory complications and problems with swallowing are also rare.
Scoliosis (curvature of the spine) occurs in some children, this is due to a weakness in the muscles supporting the bones of the spinal column. An operation can be done to straighten the spine and prevent further deterioration. They should be regularly monitored so problems can be picked up and dealt with early on. There will become a time when the decision has to be made to use a wheelchair.
Respiratory infections should be dealt with quicklly. SMA Type 3 patients may tire very easily and excess weight will add to their problems. A dietician can help give advice and support as a sensible diet is very important as unnecessary weight puts strain on the muscles, which makes moving more difficult.
Physiotherapy is very important as regular exercise helps to maintain muscle strength. Therre are some neuromuscular centres across the UK that have specially trained physiotherapists and occupational therapists.
SMA Type 4
SMA Type 4, also known as Adult Onset SMA is not life threatening. Typically symptoms begin after the age of 35 and can have a very slow progression with muscle weakness getting worse over time.
The effects of Adult Onset SMA depends on the muscles affected. The muscles used for respiratory functions and swallowing are very rarely affected. In most cases weakness only shows on one side at onset, but may progress over time to both sides of the body. There is often no pain but tired aching muscles, along with the feeling of heaviness, numbness, tingling and cramp are possible. Fatigue is very common.
As with the other types of SMA physiotherapy and regular exercise are very important to maintain mobility, and there are some neuromuscular centres across the UK that have specially trained physiotherapists and occupational therapists
This information was taken from www.actsma.co.uk