Spinal Muscular Atrophy, Information on Types and Diagnosis

Spinal muscular atrophy affects is an recessive genetic disease that affects the voluntary muscles that are necessary for many types of movements including walking, swallowing and head control. Spinal muscular atrophy affects all the muscles in the body however the largest muscles needed for fundamental movements which are closest to the main section of the body such as the hips and back, are the muscles which have the most trouble. A person that suffers from spinal muscular atrophy can have trouble with all aspects of movement and often has trouble with swallowing of food, breathing and coughing, therefore causing severe problems with choking and lung infections such as pneumonia.

People who suffer from spinal muscular atrophy however do not have issues with the ability to feel and thinking, therefore they often are exceptionally bright but feel trapped in a body that won't work. In order for a child to be affected from the disease both parents must be carriers of the abnormal gene and as the child grows their bodies are are double affected not only by the disease itself causing severe muscular control issues but also by the demands that the nerves and muscles apply to the body as the body grows larger, therefore the lack of control of breathing and movement grows as the child grows severely affecting their life expectancy.

Spinal muscular atrophy sufferers are generally split into four different groups depending on their physical motor milestones or motor neuron dysfunction. The types of spinal muscular atrophy include: Types one, two, three and four, however the course the disease takes is generally different for each child.

Type one is commonly referred to as Werdnig Hoffmann Disease and children afflicted with this type are generally diagnosed before six months in age. As well as some third trimester mothers even notice a substantial decrease of fetal movements in their pregnancy. A child diagnosed with type one spinal muscular atrophy is usually never able to lift their head or accomplish any of the basic motor skills expected in normal infancy development. Babies exhibit poor head control, are unable to kick their legs as they should or apply weight to their legs. They also exhibit feeding and swallowing problems and often have trouble managing secretions. Babies also usually are afflicted with tremors and weakness of the chest muscles used to help expand the chest with breathing, making the child appear to use their stomach muscles in order to breath with can give the chest a sunken appearance. Breathing difficulties can therefore cause the lungs to be severely affected including causing severe breathing challenges with maintaining oxygen and carbon dioxide levels when sleeping and the ability to cough and clear air passages properly.

Type two of spinal muscular atrophy is commonly made before a child turns the age of two. Children with this type of spinal muscular atrophy may often be able to sit unsupported when helped, however they can not get into the seated position on their own without help. Type two children may also with time be able to stand with assistance such as bracing. Children with type two usually do not exhibit swallowing difficulties, however some children have problems with eating enough to maintain proper weight and development and a feeding tube maybe required. Type two spinal muscular atrophy also exhibit tremors, diaphragmatic breathing, coughing and deep breathing difficulties in order to maintain proper oxygen and carbon dioxide levels. Type two children also have scoliosis issues as they grow and often require bracing and even spinal fusion at over time as they grow. Bone density problems causing an increase in fractures are also a common problem with type two spinal muscular atrophy.

Type three spinal muscular atrophy is commonly referred to as Juvenile Spinal Muscular Atrophy or Kugelberg-Welander and is likely to present in children anywhere from one year of age to as late as childhood adolescence. Type three diagnosis however is commonly done at approximately three years of age. Type three spinal muscular atrophy children can usually stand and walk but over time commonly show increasing difficulty in walking. Type three sufferers however can lose the ability to walk with growth spurts or other illnesses. Tremors are often also common in type three, however children usually don't exhibit any swallowing or feeding problems.
Type four spinal muscular atrophy commonly presents in adulthood usually presenting after the age of 35, however adult onset of spinal muscular atrophy is consider rare compared to the other types of the disease. Typically people notice weakness after 18 years of age and the progression of the disease is slow, rarely effecting the breathing or swallowing muscles. Although there is no set time limit for loss of muscular control with type four spinal muscular atrophy however loss continues with age resulting in problems with walking and movement.

Spinal muscular atrophy is diagnosed by a blood test that looks for the whether the abnormal gene is or is not present. Diagnosis is also determined by performing a complete physical examination and medical history. In some cases physicians may order a muscle biopsy or an electromyography to confirm diagnosis. However since genetic blood tests have become more prevalent biopsies are almost never needed unless the blood work is inconclusive.

An electromyography measures the muscle electrical activity. In some cases the testing can help distinguish other nerve and muscle disorders that can appear as spinal muscular atrophy. An electromyography requires small electrodes to be inserted into the muscles and an electrical pattern is observed and documented. A nerve conduction velocity test is also conducted in order to assess how the nerves are functioning on application of electrical stimuli. Small electrical shocks are administered to evaluate nerve function and integrity.

If you have a child and have noticed any weakness or muscular irregularities you should immediately see a physician in order to properly evaluate and diagnosis the problem. It is also vital that if you have a child or adolescent with spinal muscular atrophy that you get involved with a support group as soon as possible. Spinal muscular atrophy is a debilitating disease that takes a heavy toll on families and sufferers and depending on the type of the disease can affect life expectancy. There are several helpful resources that can provide you assistance and support if you have a child or adolescent who suffers from spinal muscular atrophy, as well as if you are an adult afflicted with the disease.

References for this article include:

health.google.com/health/ref/Spinal+muscular+atrophy
www.smafoundation.org/
www.fightsma.org/index.php
www.nlm.nih.gov/medlineplus/spinalmuscularatrophy.html
emedicine.medscape.com/article/1181436-overview