Muscular dystrophy

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Muscular dystrophy

Muscular dystrophy is a group of hereditary diseases that affect the musculoskeletal system. As a result, it affects limb movement due to weakening of the muscles. Muscular dystrophy is characterized by progressive muscle weakness due to death of muscle tissue cells. The weakening may also occur as a result of defects in the muscle proteins.
Muscular dystrophy can be defined as a group of hereditary diseases with progressive degeneration and weakness of a specific group of muscles. Dystrophy actually means wasting away of a particular part, organ or tissue. So muscular dystrophy involves wasting of muscles due to slight alterations in the genetic makeup. The genes contain altered information about the muscles. These dystrophies are slow in onset and usually start showing by early childhood. The primary abnormality may be in the muscle membrane. But secondary effects are marked variation in size of individual muscle fiber. The effect also includes deposition of fat and connective tissue. Muscular Dystrophy is very rare in occurrence. People with this disorder tend to have restriction of movements and sooner or later, require a wheelchair.
The Muscular dystrophy definition covers a wide variety of dystrophies which vary due to different genes being affected.
Depending on the gene involved, the symptoms and age of presentation may vary slightly.
Duchene muscular dystrophy (DMD) is the commonest and is mostly limited to boys and presents itself between 2- 6 years of age.
There is gradual weakening of muscles of hips, arms and legs due to which they are unable to walk, run and climb stairs. Survival beyond 20 years is rare in this dystrophy.

Muscular_dystrophy_poster

Muscular_dystrophy
By The Library of Virginia from USA [see page for license], via Wikimedia Commons

In the year 1860, French neurologist Guillean Duchenne, described an illness in 13 boys who suffered progressive muscle weakness. These boys were unable to walk later. Most of them died. He described the disease in several forms, based on the symptoms and the causes.

Living with Muscular dystrophy
The main affected protein in case of Muscular dystrophy is “dystrophin”.

Reduced dystrophin

The tissue is disorganized in the right affected muscle. Dystrophin concentration shows marked reduction.
By Cbenner12 (Own work) [CC-BY-SA-3.0], via Wikimedia Commons


A severe form of muscular dystrophy, Duchenne muscular dystrophy was actually named after French neurologist Guillean Duchenne who first found these cases.

The types of muscular dystrophies are different and may vary in severity of the symptoms. Duchenne and Becker muscular dystrophies occur as a result of genetic mutations on the x chromosome.
DNA mutation

DNA mutation an important cause of Muscular Dystrophy


They commonly affect males. Although female cases have also been reported.

Muscular dystrophy, how it affects ?

Clinical manifestations for muscular Dystrophy ranges from disorders of the limbs to other organs. Following is the list of organs that can show the manifestation of Muscular dystrophy

  • Eyes
  • Face
  • Limbs
  • Gastrointestinal system
  • Endocrine glands
  • Nervous system
  • Heart
  • Brain

Muscle dystrophy symptoms

The symptoms of Muscular dystrophy vary but the basic symptoms remain more or less the same. The important trait of increasing weakness of muscles is a constant feature in all the types of muscular dystrophies. Other symptoms include difficulty in co-ordination and balance while walking. This leads to frequent falling. Muscle exhaustion and weakness are hallmark symptoms. As a muscle is attached to a joint, it leads to joint stiffness and immobility. Muscles of the chest and throat are also involved which results in difficulty in breathing and swallowing. As the disease progresses, muscles of various parts of the body get involved and ultimately organs too get affected. The progression and severity of symptoms differ from patient to patient.

Muscular dystrophy diagnosis

Muscle biopsy and an electromyogram (EMG) are done to diagnose the condition. Many genetic disorders can be detected by D.N.A analysis and a muscle biopsy nowadays is reserved when genetic tests are not conclusive.

EMG_for_muscular_dystrophy

Muscular Dystrophy diagnosis may need EMG to measure electrical activity produced by skeletal muscles
By D. Gordon E. Robertson (Own work) [CC-BY-SA-3.0-2.5-2.0-1.0 or GFDL], via Wikimedia Commons

Diagnosis of muscular dystrophy in a child is normally done through testing for the levels of an enzyme called creatinine kinase in the blood. Children with muscular dystrophy tend to have very high levels of this enzyme. Further diagnostic tests may include DNA testing to look out for genetic mutations. Muscle biopsies have also been done as a confirmation. In many cases, it is the overt symptoms such as loss of muscle mass that may prompt health care professionals to do a laboratory diagnosis.

Progressive Muscular dystrophy

Progressive muscular dystrophy, showing the enlargement of the calves and the atrophy of the shoulder muscles. Progressive muscular dystrophy, facio-scapulo-humeral type.

Muscular dystrophy treatment

There is currently no cure for muscular dystrophy but patients who get help early in life have a higher chance of survival and living a more fulfilling life. There are a variety of services d for patients with muscular dystrophies. Treatment options for muscular dystrophy vary depending on the symptoms manifested. Physical therapy is important. It helps a child with muscular dystrophy to maintain muscle tone and muscle strength. It is important to keep the joints flexible. Certain devices e.g. braces may be used to prevent contractures and stiffening of the muscles. Steroid prescriptions, in particular, prednisone, have been used over the years. These are believed to slow down the rate of muscle deterioration. The aim is to enable the children to be able to walk longer and live a more active life. The side effects that come along with prednisone should be closely monitored. Patients with severe muscular dystrophy may also undergo spinal fusion. This is a type of surgery which is aimed at reducing pain and lessening the severity of the spinal cord curvature. It helps the patient to sit upright and comfortably. Additional treatments include good health care and updated vaccinations.

Unfortunately, there is no cure for this condition other than supervised physical therapy and exercise which aims at improving the quality of life as well as course of the disease. Genetic counseling is very important for couples to analyze the risk of the child inheriting this condition.

As the Muscular Dystrophy definition implies, there is muscle breakdown over a course of time. The treatment cannot reverse it yet. The prognosis is poor as respiratory and other vital muscle groups get damaged leading to a life of dependency over time.

Being a genetic condition, not much can be done to prevent muscular dystrophy. Recently, a lot of research and awareness has started. Many families with children suffering from muscular dystrophy are able to get help in terms of treatment and relevant information.

Another common muscular dystrophy is Becker Muscular Dystrophy. (BMD) is very similar to Duchene Muscular Dystrophy except that it occurs usually in adolescence and adulthood with slower degeneration of muscles.

Is muscular dystrophy contagious?

A muscular dystrophy is not contagious or infectious. It is acquired from parents right from birth. It is a genetic disorder in which some genes that contain information regarding muscles are altered. Different muscular dystrophies have different genetic alterations or mutations. Hence, they show slight variation in presentation of symptoms. Most important being that the proteins of the muscles are not produced or if produced do not perform their functions completely. These proteins are required for maintaining the strength and function of muscle fibers. As a result, wasting and degeneration occurs which results in ultimate death of the muscle fibers.

MDA.org provides good support information for muscular dystrophy patients.

Other good resource for reading is US National Library of Medicine

Muscular dystrophy causes

The main cause of muscular dystrophy is genetic defect of Dystrophin protein complex.
Muscular dystrophy is hereditary in nature and passed on in the family.

Dystrophin Protien.

Dystrophin Protien defect causes Muscular dystrophy. (PD)


Dystrophin, a protein, is normally present in the muscle fibers. This protein is deficient or absent in patients having a muscular dystrophy. There is genetic mutation of the dystrophin gene which causes muscular weakness leading to multiple problems in locomotion.
The main cause of Duchenne Muscular dystrophy (DMD) an X chromosome linked disorder is the impaired formation of the protein dystrophin by the muscle tissue.
X chromosome affected in Muscular dystrophyX chromosome affected in Muscular dystrophy (PD)

DMD is generally seen only in boys and is very characteristic since it is X linked. Becker Muscular Dystrophy (BMD) like Duchenne affects only boys but the variation is that there are partially complete forms of dystrophin protein seen in the muscles.

Myotonic muscular dystrophy is another variant in which the cause is autosomal dominant linkage. i.e. the autosomal type of chromosomes in the cells are affected. It is passed on to 50 % of the offspring.

Congenital muscular dystrophy could be caused by multiple gene linkages and hence very dangerous and rare.

The dystrophin protein is necessary for the movement of muscles and since this protein is lacking there is manifestation of the various symptoms.

A deeper understanding of the muscular dystrophy causes will help us understand how a patient presents with progressive muscular weakness which travels from the upper part of the body and then goes lower down. This weakness leads to difficulty in walking and limits mobility. Patients prefer to be static in one place. Even if they walk, they tend to fall often. This leads to bruising of joints and a waddling (penguin-like) gait.

Contractures of tendons leads to stiffness of joints. This is a common finding in this disorder. There is enlargement of calf muscles to help compensate for the inherent weakness but in reality the muscles are wasted. Extreme cases will display difficulty in breathing, drooping of eyelids and spasms of muscles. Difficulty in speaking and later, breathing often lead to becoming bedridden.

Drooping eyelids in muscular dystrophy Drooping eyelids in muscular dystrophy
Cumulus at nl.wikipedia [GFDL or CC-BY-SA-3.0], from Wikimedia Commons

Weakening of chest and back muscles could cause the spine to have a curve. This condition is called as Scoliosis. Scoliosis (abnormal sideways bending) of the spine leads to lack of appropriate posture habits.

Scoliosis due to weak chest and back muscles Scoliosis due to weak chest and back muscles.By Weiss HR CC-BY-2.0 via Wikimedia Commons

Gower’s sign is a very important diagnostic sign which helps in differentiating muscular dystrophy from other conditions. In Gower’s sign, the person finds it difficult to get up from sitting position and hence first raises the thighs and the hip such that the person is half bent over and then by putting all the pressure over the knees, pushes himself over the floor. It appears that the patient is ‘climbing over himself’.

Gower's sign important feature of Muscular dystrophy

A grasp of the muscular dystrophy causes have laid down the foundation for better treatment of the condition. Medical treatment of this disease has been tried with various drugs but prednisone (steroid) has shown the best results. A low dose of prednisone will palliate the symptoms initially.But later there tends to be complications due to long term therapy with prednisone. Creatine monohydrate supplementation has shown slight increase in muscle use and also in reduction of the weakness to some extent. Surgical therapy comes in the picture when there is severe weakness along with deformities. Orthopedic correction comes into play to correct the deformities of the foot and the contractures of joints. The foot deformities start off early and the joint deformities come at a later age. Scoliosis needs to be corrected with braces and a belt, as it is seen early in life and keeps progressing.

So it is important to note that Muscular dystrophy causes do not include the following-

  • Infection of any form from other patients.
  • Infection from Bacteria or virus
  • Any food or nutrients related deficiency
  • Lack of exercise or disuse of muscles

Is muscular dystrophy hereditary ?

Yes, Muscular Dystrophy is hereditary.
Muscular dystrophy is a group of chronic hereditary diseases characterized by progressive degeneration and weakening of muscles. As a result, the musculoskeletal system weakens and hinders the body movement.
It is believed that muscular dystrophy is more of a childhood disease. However the clinical onset may occur at any point in life. Different types of muscular dystrophy vary in age of onset, degree of muscle wasting and the groups of muscles affected.
Muscular dystrophy is certainly hereditary. This means that there is a genetic link to the cause of this disease. It comes about as a result of changes(mutations) in the genes that are responsible for structure and function of one’s muscles. These mutations cause changes in muscle fibers.
Muscles are made up of group of cells called fibers which appear in bundles. On the membranes surrounding these fibers are a group of proteins that aid in the functioning of the muscles. This happens mainly because of the largest gene called Dystrophin in humany body. This may be either absent, defective or partially present in cases of Muscular Dystrophy.
The changes(mutations) in muscle fibers are often inherited and hence the different Muscular Dsytrophy types follow different inheritance patterns. The genetic defect may be transmitted by one parent in some conditions and by both parents in others. However many cases are even seen for muscular dystrophy in families with no history of the disease. This is believed to be a result of a highly spontaneous mutation rate. The mutation may have existed in the family without being known or a new genetic mutation may actually take place in the mother’s eggs cells
Duchenne Muscular Dystrophy is inherited in a x-linked pattern since the gene that carries the mutation is on the X chromosome.

Is Muscular Dystrophy hereditary?

Muscular Dystrophy is hereditary. [P.D]-Wikimedia Commons

 

How is Duchenne muscular dystrophy hereditary ?

An example of the genetic inheritance link for Duchenne muscular dystrophy is seen above .Based on the diagram, males have an XY chromosome while females have XX chromosome. Every boy inherits an X chromosome from the mother and a Y chromosome from his father. A girl gets one X chromosome from the mother and another X chromosome from the father.
When a boy is born to a woman with a Dystrophin mutation on one of her X chromosomes, he has a 50% chance of inheriting the gene and suffering from muscular dystrophy. Each of the daughters belonging to this woman have a 50% chance of also inheriting the mutation and being carriers. A carrier does not have any disease symptoms, but their child can be born with the mutation.
A male with Muscular dystrophy is unable to pass the flawed gene to his sons because he gives the Y chromosome and not an X. But he will certainly pass it to his daughters since girls inherit their father’s only X chromosome. They then become carriers and each of their sons develops a 50% chance of developing the disease and so on.

 

Girls usually do not get muscular dystrophy because when they inherit the flawed Dystrophin gene, they also get a healthy Dystrophin gene from the other parent and thus end up having enough Dystrophin to protect them from suffering from the disease. Boys who inherit the flawed gene get the disease because of lack of a second Dystrophin gene to make up for the faulty one.

REFERENCES

1. 1: Emery AE. The muscular dystrophies. Lancet. 2002 Feb 23;359(9307):687-95.Review. PubMed PMID: 11879882.

2. 1: Hsu YD. Muscular dystrophy: from pathogenesis to strategy. Acta Neurol Taiwan.2004 Jun;13(2):50-8. Review. PubMed PMID: 15478675.
3. http://www.mda.org.au/Disorders/Overview.asp
4. http://www.muscular-dystrophy.org/about_muscular_dystrophy/conditions

Muscular dystrophy Types

There are nine main types of Muscular dystrophy.
These are Becker, Facioscapulohumeral, Myotonic, Distal, Duchenne, Emily-Dreifuss, Limb Girdle, Oculopharyngeal, and Congenital Muscular Dystrophy.
But there are also some conditions that mimic muscular dystrophy and cause the same symptoms. Therefore extensive tests and investigations need to be done before coming to a conclusion of Muscular Dystrophy.

Duchenne Muscular Dystrophy

This is unfortunately the major life claimer of all the Nine Muscular Dystrophy types. It affects only boys. It usually shows up in toddlers. By the time child reaches teenage, he might be severely crippled. DMD is caused by the absence of a gene called Dystrophin. Severity of condition is directly proportional to the amount of Dystrophin absent. The lesser dystrophin a child has in his DNA, the lesser is his chances of surviving beyond adulthood.

What to expect as regards life span of Muscular dystrophy ?

Muscular Dystrophy type 2: Facioscapulohumeral Muscular Dystrophy (FSHMD, FSHD or FSH)

This Muscular Dystrophy type affects both males and females almost equally. As the name suggests, muscles of the face, shoulders and upper limbs are the first ones to be weakened. The prognosis is not that great, and it has been proved that the majority of affected population is in its teens . It leads to severe disability and failure of respiratory system, that may often cause death.

 G. Duchenne who discovered Duchenne muscular dystrophy. Later on other Muscular dystrophy types were discovered.

Duchenne Musculat dystrophy named after G._Duchenne
via Wikimedia Commons by PawełMM

Facioscapulohumeral muscular dystrophy - One of the Nine Muscylar Dystrophy types

Facioscapulohumeral muscular dystrophy

Main Symptoms of FSHMD

  • Weakness in muscle of face. This results ins drooping of eyelids poor expression of face and difficulty in pronouncing certain alphabets.
  • Heart beat/ rhythm is irregular.
  • Shoulders become weak. The patient cannot raise shoulders, they tend to droop.
  • Patient is unable to hear properly.
  • Sometimes even foot drop is seen in such cases.
  • Muscles of abdomen, lower arm, triceps, biceps and deltoids are weak.

 

Myotonic Muscular dystrophy

This condition is of two types, both of which present with Myotonia or a delayed muscle response specially when relaxing the muscle after contracting. Visualize it this way, the person can pick up a glass full of water, but his muscles would resist keeping the glass down swiftly, causing a much delayed and sometimes-painful reaction. Type 1 Myotonic Muscular dystrophy type is the most common of all such dystrophies and is caused due to repetition of an essential muscle protein twice in the DNA. On the other hand, the type 2 is much rarer and is caused when one muscle protein is expanded beyond its usual size in the Human DNA.

Emily-Dreifuss Muscular Dystrophy

The common population affected by this Muscular dystrophy type is often children or young toddlers. It has three subtypes that dictate the prognosis of the condition, but all have some or more mutations or defects in the EMD gene. Children often exhibit cardiac conditions along with muscular dystrophy like valve defects and arrhythmia. The cause of this change in gene structure remains unknown.

Congenital Muscular Dystrophy

This Muscular dystrophy type is one that is reported at birth itself. Or it may show up to an age of one year. The life span of the child is greatly reduced. The weakness starts from the legs and soon enough, takes over all the body. Sometimes the child may also exhibit neurological problems such as memory difficulties and lower IQ levels. These are also caused by defective muscle protein that is important in formation of Glycoprotein- dystrophin complex. This complex is essential for muscle health.

Limb girdle Muscular Dystrophy

This type of Muscular dystrophy covers a vast subgroup. It has many conditions as subtypes, but most of them exhibit the same symptoms of muscle weakness and progressive deformities in the legs. Usually both girls and boys are equally affected. This shows up mostly in the teenage years. Death is often associated in case complications from heart or respiratory system arise.

Oculopharyngeal Muscular Dystrophy

As the name suggests, the muscles of the eye, throat and face are the first ones to get affected in this Muscular dystrophy. The usual affected population is between 40 to 80 years. It is caused by the repetition and expansion of one gene in the otherwise normal chromosomal structure.

Becker’s Muscular dystrophy

This is a form of muscular weakness, which is considered less severe than other forms of Muscular dystrophy types. It affects only males. It exhibits formation of a distorted dystrophin gene that is slightly functional, unlike other conditions where there is no formation of dystrophin. The patients can survive up to old age after prompt diagnosis. Becker’s Dystrophy has a better prognosis than most of others.

Distal Muscular Dystrophy

This is the least life threatening of all Muscular dystrophy types. The usual affected population can be anywhere between 20-60 years of age. The wasting of upper limb muscles as well as small muscles of the foot is common. The cause of this muscular dystrophy is a defective gene. Thisis the same gene that is involved in Limb Girdle Dystrophy.

Muscular dystrophy life expectancy

Muscular dystrophy life expectancy is an very important aspect that the patient and their families need to understand and cope up with.
Almost 50,000 people are affected by Muscular dystrophy of one or the other type in US today.
Muscular dystrophy is a disease comprising of almost 20 different genetic disorders. This disease is seen more in males than females. It has no specific tendency towards race or ethnicity. However, the life expectancy completely depends on the condition, as well as the age at the time of diagnosis. In this disease, muscles are destroyed over a period.
The only unifying symptom of all forms of muscular dystrophy is the fact that over time, muscles degenerate and start atrophying. The people, mostly children, suffering from this disease cannot escape the muscle deterioration. This is one fact that those affected need to face. The life expectancy is totally dependent on the type of Muscular dystrophy and the time when it was first diagnosed. In some conditions, live expectancy is severely reduced like Duchenne’s while in others it remains fair and sometimes has a good outlook.

Muscular Dystrophy Life Expectancy for each type

Duchenne muscular dystrophy life expectancy

This condition is notorious for mostly affecting the boys. In specific rarities it may affect females too. In this case, the child becomes wheelchair borne, just years after the diagnosis.

The stats shown in the figure below have been adapted from

Duchenne Muscular Dystrophy - Life Expectancy

Duchenne Muscular Dystrophy – Life Expectancy

This happens often in the 10 to 11-year range. Not only they get restricted to wheel chair but they face heart and other respiratory problems due to an increase in muscle weakening. The predicted life expectancy is only 20 to 25 years from the time of birth. The quality of life is quite poor in the last few years.

Congenital muscular dystrophy life expectancy

This disorder causes weakening of muscles along with mental disabilities from the birth itself In this case, the life expectancy depends on how the patient is coping up and the sub type. It is a very variable condition with multiple types. In some, it may remain asymptomatic until adulthood, while in some it may cause behavioral and intellectual disabilities, making their life expectancy not so favorable.

Becker muscular dystrophy life expectancy

This disorder is less dangerous as compared to others because the limb movement is still there . In this case, the longevity of life is not much affected in some cases. At the same time, there could be cases of harsher prognosis too. The patient may continue to have health issues even if they live longer. The life expectancy depends on the progress of the disease. 50% of the deaths in case of BMD occur because of Cardiomyopathy.

Distal Muscular dystrophy life expectancy

As the name suggests, distal muscular dystrophy usually affects lower limbs. It is spread over a huge age group pattern, the age of diagnosed patients can be anywhere between 5 to 50 years. The prognosis is fair, and the life expectancy is favorable as long as respiratory muscles do not get affected. In case of respiratory involvement, the life expectancy would be considerably reduced.

Emily Dreifuss Muscular Dystrophy life expectancy

The classic feature of Emily Dreifuss is the presence of cardiological symptoms in the patient. These symptoms worsen the patient’s state. The muscles often develop contractures. These are adhesions that decreases joint motion. The patient requires a wheelchair by adulthood. Most of the adult patients have heart problems. Irregular electric signals in the heart could become serious. This could be the main reason of reducing Life expectancy in this dystrophy. The problems of heart rhythms could lead to sudden death or stroke.

Facioscapulohumeral Muscular dystrophy life expectancy

The disorder usually presents in adults and the prognosis is not very favorable. Within years of diagnosis, the patient can lose the ability and functions of facial and upper limb muscles. The usual life expectancy is favorable. Some patients may even survive beyond the age of 40. Again longevity is possible only if respiratory muscles are not involved early in the disease progression.

Limb girdle muscular Dystrophy life expectancy

This is one of the biggest subgroups, with more than 20 conditions classified under it. However, the total affected cases are relatively less. The life expectancy depends on the systems affected but is usually well into the late 60’s and 70’s. This is if cardio pulmonary system is not involved.

Myotonic Muscular Dystrophy life expectancy

This is the most common muscular dystrophy of all in grown ups. This condition is not too life threatening. But it is uncomfortable and distressing. Stiffening of muscles is a important indication of Myotonic muscular dystrophy. The condition becomes worse in cold climate. Muscular jerks and resisted movements are a classic sign. The prognosis is good, and with some muscle relaxants, the life expectancy is as good as normal. In the absence of accompanying complications the patient can go on living a normal life cycle.Life expectancy is reduced but not very bad.

Oculopharyngeal Muscular dystrophy life expectancy

This condition does not start showing symptoms unless the patient is in his late 40’s to 70’s. This makes it probably one of the least dangerous in terms of affected life expectancy. The patient may survive about two three decades after diagnosis.
Reference: Webmd

Improving muscular dystrophy life expectancy

Owing to the worsening muscle weakness, in some severe Muscular dystrophy types, life expectancy tends to be poor, especially beyond the age group of 20s. It is a genetic disorder that results from the faulty production of a gene called as ‘dystrophin’. This gene is responsible for a healthy build up of the muscular cells. Without this protein, the muscles cannot develop to their best and the affected child has difficulty in performing his everyday activities.

The life expectancy of a person with Duchenne muscular dystrophy type is generally about 28 years of age. This is the average age that researchers have concluded after years of study done on a large number of patients. There are multiple types of muscular dystrophies, of which Duchene muscular dystrophy is the commonest and results in poor life expectancy for muscular dystrophy. This disorder affects each and every muscle in the body. It starts with the skeletal muscles such as shoulders, hands, arms and gradually progresses to the lower limb muscles. The most important muscles such as of that of the heart and lungs are also affected as the age progresses. This determines the survival rate of an individual’s life and overall Life expectancy

Muscular dystrophy life expectancy factors

At a younger age, like in case of toddlers, the child experiences difficulty in walking, climbing and running. They develop delayed milestones. Usually, it progresses to a stage where the child can no longer walk. The muscles responsible to chew food are affected too. The child’s speech is often affected.

Non invasive ventilation

Cough assisted mechanically with oximetry and continuous NIV(Non Invasive Ventilation) can improve life expectancy in Duchenne muscular dystrophy. This will also avoid the use of Tracheotomy.
Various studies have shown some good results with ventilation of this mechanical type. This ventilation is particularly useful for patients with DMD.

Non invasive ventilation

Non invasive ventilation
By PruebasBMA (Own work) [CC-BY-SA-3.0], via Wikimedia Commons

A survival rate of about seventy five percent was observed in DMD patients provided with Home Mechanical ventilation.
Deaths occurrences were more because of bleeding in Trachea and Cardiomyapathy.
At the age of 20 and beyond, the muscles of the heart and lungs become weak.
Mask for Non Invasive Ventilation.

Mask for Non Invasive Ventilation.
By Timt775 [PD]


At this stage, the life expectancy is very poor. Studies have shown that patients on mechanical ventilator support for breathing have improved their survival rate. Mechanical nocturnal ventilator support i.e. ventilation provided at bed time, supports the breathing and reduces the load on the muscles responsible for breathing in the chest and lungs. Individuals monitored on nocturnal ventilation did not have to undergo tracheostomy, a surgical procedure where a hole is made in the wind pipe to aid breathing. Few patients reported to experience fatigue during the day. They were then advised to be ventilated once in the day and thereafter, they showed significant improvement. In these individuals, the life expectancy increases by a couple of years. Some of them have even survived for decades together without any complications.

Infections and muscular dystrophy life expectancy

The other factors affecting Life expectancy in Muscular Dystrophy are presence of any infections of the lungs or any cardiac diseases. Studies reveal that many patients treated with steroids have shown improvement, in a way that they have delayed the area of immobility and dependency. Also the lung dysfunction has been successfully prolonged. The supportive treatment useful in prolonging the life expectancy includes use of good nutritive and healthy food rich in proteins, vitamin D supplements, use of anti inflammatory meditations and vaccination to prevent chest infections such as flu and pneumonia.

muscular dystrophy life expectancy and Serum creatnine kinase

Serum creatnine kinase determines the level of muscle damage. This is tested by doing a simple blood test. This enzyme is released in the blood stream with the breakdown of the muscle fiber thus estimating the progress of the disease.
Thus, though it is a fatal disease in cases of muscular dystrophy, life expectancy can be on an average up to 28 to 30 years of age. The life expectancy can be as good as up to 48 years in individuals with no cardiac complications and proper medications and ventilator support. This is usually seen in Becker’s type of muscular dystrophy. Death with respiratory complications and infections such as pneumonia are more frequently seen than cardiac complications.

Myotonic Dystrophy Life Expectancy factors

Persons suffering from Myotonic dystrophy tend to have much varied Life expectancy. Some may even live a normal life thereby showing a better life expectancy. But when this dystrophy starts at a very early age say even from birth, being congenital type, the Life expectancy is not good. The child could die quite early or sometimes live for a couple of years.
Those showing myotonic dystrophy symptoms at early age also carry higher risk of poor life expectancy. It is observed that usually deaths in case of myotonic dystrophy occur more by pneumonia, respiratory issues or heart problems.
If a person is diagnosed with myotonic dystrophy, its a must for for him disclose this to any Doctor he visits for consultation.
It’s important to note that with this dystrophy, there are likely to be issues with child birth and general anesthetics.
Ref
Non-invasive ventilation and continuous positive pressure ventilation

Myotonic muscular dystrophy

Myotonic Muscular dystrophy is a group of disorders which are characterized by progressive muscular weakness. This may occur without an infection or inflammation. This disorder is also referred to as Myotonia Atrophica Muscular dystrophy. Myotonic Muscular dystrophy is a long term disease which affects many systems of the body.

Heart conduction myotonic

Heart conduction gets affected in myotonic dystrophy Heart conduction problems myotonic dystrophy / CFCF / CC A 3.0


The main symptoms of this muscular dystrophy are muscular weakness, cataract, defective conduction of the electrical impulses in the heart and loss of muscle tone.

Myotonic Muscular dystrophy Types

Myotonic Muscular Dystrophy is divided into two types. Type 1 is called as Steiner’s disease. This is a hereditary form of the disease. It is caused due to a defect of ‘myotonic dystrophin protein kinase’ gene (DMPK). This protein is located on chromosome 19. Type 2 is also called as proximal myotonic myopathy. This one is a result of a genetic defect of the ZNF9 gene situated on chromosome 3. Type 1 is seen more often than the type 2 form.

Symptoms of Myotonic muscular dystrophy

Symptoms for both the types generally start while attempting to execute functions. There is lack of concentration and difficulty in word-finding. There is a rapid tendency to have heart blocks. Hence an Electrocardiogram is advised every year. Other heart conditions which are involved in this disease are an altered electrical conduction system of the heart. The heart conduction may be slow or much faster than normal.

 

Bilateral cateract serioud

Bilateral cataracts Patho /

A cortical cataract in the lens of the eye having a bluish discoloration is a very important feature and diagnostic of this disease. This helps in diagnosing the disease faster. Bilateral cataracts should be treated at the earliest as they might completely blind the person.
Insulin resistance is also seen in many cases and hence, there is hormonal involvement too.

Insulin resistance

Insulinresistance – symptom of myotonic dystrophy

Prognosis and Treatment for Myotonic muscular dystrophy

Myotonic Muscular Dystrophy is a genetic disorder. It passes to almost 50 % of the offspring from an affected parent. It is a life threatening condition and should be diagnosed during the pregnancy itself in families who are suffering from the disease. The genetic testing is the gold standard for diagnosing when the fetus is in the womb.

Genetic testing

Genetic testing


Proper care needs to be taken for kids. This should be done by a combined team of endocrinologists, cardiologists, ophthalmologists and pediatricians.
From the prognostic point of view, these children are in a state where years can be added only by extra support and care. This Muscular Dystrophy is as yet an incurable disease. But, the quality of life can be improved with appropriate medications, exercises and orthopedic or surgical measures. These children usually die by the age of 30 years. The cause of death is usually a heart failure.
Appropriate mobility exercises must be done regularly for Myotonic Muscular Dystrophy. This will help in releasing and reducing the contractures of the patient. Aerobic exercises must be done. These will improve the fitness and stamina levels.

A stationary bicycle, for example, will improve the cardiac health of the patient. Appropriate support belts will reduce the exertion of the muscles. They will also allow more independence for the patient. Patients should be given adaptive equipments. They should be taught to walk right. The cardiac evaluation must be done yearly.All co-morbid conditions should be prevented aggressively. Pacemaker insertion in the heart might help people with altered cardiac function tremendously. Sleep apnea i.e. a pause in the breathing while sleeping, may lead to daytime sleepiness;

Avoid sleep apnea

Avoid sleep apnea By Drcamachoent (Own work) [CC-BY-SA-3.0], via Wikimedia Commons

.
Sleep studies must be done. Taurine and clomipramine are the two drugs which improve the muscle tone of the patients slightly. They may be considered for long term use after consulting the physician

Myotonic dystrophy symptoms

are similar to other muscular dystrophies wherein there is increasing muscular weakness and degeneration. Apart from this, myotonic dystrophy also shows myotonia, which is an inability of the muscle to relax after contraction. As a result, the muscle remains in a prolonged state of spasm or contraction. Myotonic is an adjective of myotonia which means delayed relaxation, and sustained tonic spasm of muscles. Myotonic dystrophy is the commonest type of adult muscle dystrophy and affects about 1 in 8000 people globally. There is an equal prevalence for both males and females.

Myotonic dystrophy symptoms vary from individual to individual and are not only limited to muscles but can also affect other parts of the body. This condition is also known as Steiner’s disease. It is a genetically inherited disease with two types- Myotonic dystrophy 1 and Myotonic dystrophy 2. The difference between the two is that different genes are affected in both the variants.

Myotonic dystrophy onset

The onsets as well as symptoms vary in both the types, with Myotonic dystrophy 1 being more common than the other. Typical presentation is around 25 years of age. The earlier the onset of the disease the more severe is the presentation of this condition.

Myotonic dystrophy affecting muscles of face, hands and feet

One of the primary symptoms of Muscular dystrophy is muscle stiffness or Myotonia. Most commonly, the muscles affected are those of the face, hand, neck and feet. The other bigger muscles like that of the thigh and hips are rarely affected initially. Muscle wasting and weakness of the face give rise to a long thin haggard face which is very typical. There is shrinkage in the bulk of the muscles. The patient may not be able to shake hands properly or the grip of the hands will be very weak. These initial symptoms may go unnoticed initially.
Balding of the front of the scalp may also happen slowly. There will be drooping of eyelids and there will be difficulty in holding the head straight up.

Myotonic Dystrophy affecting muscles of respiration

Respiratory muscles are also affected which results in difficulty in breathing, poor lung function and reduced oxygen supply to the body. It can also lead to sleep apnea where a person stops breathing for a few seconds during his sleep. Difficulty in swallowing and speech can also occur as disease progresses.

Myotonic Dystrophy resulting in CARDIAC IMPAIRMENT

Cardiomyopathies is a common symptom of Myotonic Muscular Dystrophy. Basically, the part of the heart which conducts and regulates the heart beat and rhythm gets affected. Dizziness and fainting spells should not be neglected as this could be due to a block in the electrical conduction of heart. This can prove to be fatal if ignored.

CATARACTS in Myotonic dystrophy

Patients may also complain of blurring of vision that is worsening. This is due to cataracts which are common accompaniments in both the types of myotonic dystrophies.

HORMONAL ABNORMALITIES in Myotonic dystrophy

Abnormalities in the hormonal system occur mainly as insulin resistance, where a patient develops a condition of high blood sugar. This occurs more as the muscles require more amount of insulin to breakdown sugar. Atrophy or degeneration of ovaries and testes can also occur as a result of Myotonic dystrophy.

Myotonic dystrophy and its effect on internal organs

Lastly, other internal organs also get affected; mainly the digestive tract, uterus and blood vessels. Reason for this is that these internal organs are hollow and muscular. There is slow passage of food through the tract due spasms due to which food gets stuck. Muscles of the lower digestive tract are also affected leading to diarrhea and constipation. In women, there is difficulty in childbirth. Blood pressure tends to remain low due to slow flow of blood through blood vessels.

Myotonic dystrophy BRAIN IMPAIRMENT

Overall effects on the brain are not well documented but it can affect personality, cognition and alertness. Some level of mental impairment maybe noticed.
Severity of Myotonic dystrophy can be reduced but not the disease cannot be completely cured. Physical therapy, exercise and medication can improve the outcome of this disease. Most patients go on up to middle age. Genetic counseling is very important for couples with this condition.

Distal Muscular dystrophy

Distal Muscular Dystrophy or Distal Myopathy is a form of Muscular Dystrophy that effects people between the ages of 20 to 60 years, and has a fair prognosis. It is the rarest form of Muscular Dystrophy and is not considered particularly life threatening. It affects the muscles at the extremities like the hands, lower legs, feet, and lower arms. Distal Muscular Dystrophy diagnosis is extremely difficult. This is because it is caused by the mutation in any one of eight genes. It can be inherited from one or both the parents. The symptoms usually show up when the patient is in their 40s or 50s.

Distal Muscular dystrophy

Distal Muscular Dystrophy Diagnosis

To diagnose distal muscular dystrophy, physicians carry out extensive tests. First step is a thorough family history and physical examination. Eventually blood serum analysis, CT scans and MRIs may be advised. Genetic studies in the form of gene mapping may be ordered to understand the level of mutation better. Once the level of mutation and its severity has been identified, the patient can then be classified as one of the many types of Distal Muscular dystrophies.

A serum protein assay could very often show elevated serum Creatine Kinase (often referred as CK). A number of tests and lab visits may be needed to judge the source causing elevated CK. Sometimes a muscle biopsy is recommended. The Biopsy is when a small fragment of muscle is cut and visualized under a microscope. This helps to find out the muscle protein that is actually lacking. A biopsy can sometimes prove to be a definitive diagnostic tool.

Distal Muscular Dystrophy types

There are eight different types of Distal Myopathy:

  1. Body myositis type 1-Hereditary inclusion
  2. Nonaka Distal Myopathy
  3. ZASP-related myopathy
  4. Miyoshi Distal Myopathy
  5. Welander’s Distal Myopathy
  6. Finnish Distal Myopathy, which affects the tibia
  7. Gower- Laing Distal Myopathy
  8. Distal myopathy along with vocal cord and pharyngeal weakness

Distal Muscular Dystrophy Symptoms and Progression

The first symptoms of Distal muscular Dystrophy appear in the distal muscles. These are the muscles farthest from the hips and shoulders. These are the muscles in the hands, lower hands, feet, and lower limbs. However, as the time progresses, it affects other groups of muscles as well. Finally, the patient loses the ability to function normally. Daily tasks such as walking, sitting up etc become almost impossible.

Some forms of Distal Muscular Dystrophy affect the muscles in the neck. This restricts swallowing and speaking. The heart muscles are also affected in some cases. However, this disease does not affect the intellect, thereby giving the patient a much better life. At times, the muscles are affected so severely that the muscles may become visibly weak and the limbs of the patient could even shrink inwards.

Distal Muscular Dystrophy causes

The causes of Distal muscular dystrophy are difficult to determine.This is because it is a genetic disorder that can be a result of a mutation in any one of eight different genes. The disease can be inherited either from a single parent or from both the parents.In this condition, it can be dominant or recessive. The latter means that the person will not exhibit any symptoms. It can be a result of a dominant or a recessive gene present in one or both the parents.
It is therefore advisable to get oneself checked before planning a child in case the parents have a history of muscular disorders in the family.
Read more about SMA type 1

Distal muscular dystrophy Treatment & support

A large number of treatment options are available for the patients. Some of these procedures include physical therapy, surgery, occupational therapy, better nutrition, respiratory care, and cardiac care. The treatments does not ensure complete cure.But it helps improve the quality of patient’s life. A lively and enthusiastic family participation has often shown tremendous results in the lives of those suffering from Distal Muscular dystrophy.

Congenital Muscular Dystrophy

Congenital Muscular Dystrophy or CMD is a type of Muscular dystrophy that is present in the children since birth. And hence the name Congenital Muscular dystrophy This disease affects the joints and gives rise to many deformities. The disease progresses slowly. The life expectancy of the patient varies. In some cases, Congenital Muscular dystrophy does not affect the duration of life at all. The infants born with this disease have poor muscle rigidity and appear to be ‘floppy’. With age, the muscle rigidity and strength may improve or worsen. Affected children may start walking later than other children. They may lose the ability to walk.

Congenital Muscular Dystrophy diagnosis

Usually diagnosed in a newborn child, this condition is usually hard to miss. The limbs appear flail and floppy and a mere physical examination usually is enough to diagnose or form a preliminary diagnosis. As the child grows older, the confirmation may be received thorough gene mapping tests. These can help get a better clinical picture. It would also help visualize the form of mutations and severity. It is important to note that early blood tests and even complete blood counts would not be much helpful. This is because blood serum markers essential for making a definitive diagnosis for Congenital Muscular dystrophy are not present in the early stages of disease. Later on, when the child is above 5 years old, bone scans, and x-rays would be advisable.
These would help identify bony changes if any occurring due to fragility of muscles.

How is the life span of muscular dystrophy ?

Congenital Muscular Dystrophy types

1. Congenital Muscular Dystrophycaused by Laminin-α2–deficiency
2.Congenital Muscular Dystrophy affecting muscle, eye and brain (MEB)
3. Rigid spine with muscular dystrophy Type 1
4. Congenital Muscular Dystrophy plus type 1 due to secondary laminin deficiency
5. CMD with mental retardation and pachygyria
6. Congenital Muscular Dystrophy plus type 2 due to secondary laminin deficiency
7. Walker Warburg Syndrome
8. Ullrich congenital muscular dystrophy
9. Fukuyama CMD

Congenital Muscular Dystrophy causes

Congenital Muscular Dystrophy is inherited due to the presence of a mutation in one of the genes of one or both the parents. The mutated gene lacks one or more of the proteins thus leading to the disease. The offspring of an individual with this disease has a 50% chance of inheriting the disease and a 25% chance of being the carrier of this condition. A carrier is usually asymptomatic but passes on the condition to his or her offspring, in whom the condition may chose to be dominant or be recessive again making them a carrier.

Congenital Muscular Dystrophy symptoms and prognosis

Congenital Muscular Dystrophy is present in infants at birth and hence the symptoms appear right at the birth of the child. The child appears to be less rigid than other infants are. The children with this type of muscular Dystrophy might not walk at all. Children with CMD might lose the ability to walk during early childhood in which case they might need crutches or wheelchairs.

Since the disease is cognitive, it affects the brain and its functions the most. The disease may lead to complete failure of any cognitive abilities.

Seizures as well as structural deformities of the eyes or even brain are very common in most of the cases of Congenital Muscular Dystrophy.

White matter abnormalities that present with little or no effect on cognitive abilities have been seen in the Laminin-α2–deficient type of dystrophy.

Congenital Muscular Dystrophy treatment

Although no treatment can completely cure an affected individual. Some treatments are required to help the patient lead a better life. Nutrition and proper feeding is one of the important steps. Physiotherapy, use of cough devices, surgeries, splints, braces, mechanical ventilators etc. are some of the other ways that help to improve the quality of life of the patient. Since Congenital Muscular Dystrophy affects the patient ever since their birth, the quality of life remains poor throughout their life.
The use of external devices only help to relieve some of the pain, and such patients remain dependent on their families and loved ones for supportive care and proper rehabilitation.

alpha2 chain-deficient congenital muscular dystrophy

A pharma venture called Merozyne Therapeutics AB has started working on a medical treatment to combat alpha2 chain-deficient congenital muscular dystrophy.

MDC1A is a aggressive uncommon form of muscular dystrophy that happens due to mutations in a gene.
This gene is the one which encodes the alpha2 chain relating to extracellular matrix protein laminin (merosin).

At present, there is no treatment for MDC1A and those affected have a very bad life expectancy

What is Oculopharyngeal muscular dystrophy ?

Oculopharyngeal muscular dystrophy is a neuromuscular muscular dystrophy that mainly affects muscles of face, and throat. It also affects the ability of speech. Hence it affects parts of brain as well as muscles. It is usually autosomal dominant. This means that there is only one copy of the faulty gene causing the condition. It can also be recessive. As these condition may require both parents to pass on one faulty gene copy.

It is very difficult to diagnose this condition. This is because the symptoms are quite similar to Myasthenia gravis. Myasthenia gravis is an autoimmune condition, that affects the muscles in the same pattern as OMD. Myasthenia gravis can be verified by presence of blood serum antibodies in blood test. These antibodies are absent in OMD. This dystrophy is not a life threatening condition on its own. Death only ensues when there are severe complications.

Oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy diagnosis

New advancements like blood genetic testing for PLABPN1 gene, offer quick diagnosis. A muscle biopsy is required to make this diagnosis. In this test, a small sample of muscles from the affected site is taken. This is tested for lack of specific muscle proteins. This helps to differentiate it from other similar conditions. Mitochondrial myopathy is another condition that resembles OMD. Once Myasthenia Gravis and Mitochondrial Myopathy are ruled out, diagnosis of OMD becomes obvious.

Types of Oculopharyngeal Muscular Dystrophy

There are only 2 types of Oculopharyngeal Muscular Dystrophy. They are distinguished based on inheritance.

• Autosomal Dominant OMD
• Autosomal Recessive OMD

Both the types have completely different severity of symptoms. They also dictate, whether the person will be truly symptomatic or not. When this condition is dominant, the person shows characteristic symptoms. In recessive, the person remains a carrier not displaying any true symptoms at all.

Oculopharyngeal Muscular Dystrophy Symptoms and progression

The characteristic symptom is the presence of droopy eyelids at first. This is the first feature to be seen. Once this phase starts, swallowing becomes a little difficult. It is usually at this phase that the patient reports to the doctor’s office. The difficulty in the beginning is only limited to swallowing solid food. With the severity and progression of the disease, soon enough swallowing liquids also becomes difficult.

After this phase, patients start complaining about muscular weakness in tongue and some part of the face. The altered muscular strength makes it difficult to consume food. This starts malnutrition and weakness in the patient. Weakness is not just limited to face, some patients even report losing strength in their legs and lower limbs.

Oculopharyngeal Muscular Dystrophy Causes

There is only one cause, that has been proven until date and that is genetic. Inheriting faulty defective genes, which have mutations, can eventually lead to a patient having this condition. The severity and type of his condition will depend on the number of copies of the defective gene he has received from his parents.

Oculopharyngeal Muscular Dystrophy treatment

The condition is not considered particularly life threatening unless the respiratory passage is blocked. It is however essential, in this condition to manage the symptoms patients have. Initially, anti-inflammatory medicines are prescribed to keep the swelling of esophagus to a minimum. If this fails, intubation may be necessary to keep the air passage intact.

Intubation for oculopharyngeal dystrophy

Intubation for oculopharyngeal dystrophy
By PhilippN [Public domain], via Wikimedia Commons

This is done to provide proper nutrition to the patient to keep immunity up.

Oculopharyngeal muscular dystrophy Diet

A balanced healthy diet is necessary to manage the condition. Physical therapy is a great place to start. The services of a speech therapist may also be needed due to speech problems. Some surgeries like Crico-pharyngeal myotomy may be required to manage condition effectively. In this surgery, muscle layers are cut, to keep the windpipe free from muscular blockages. Prompt medical care and attention, can successfully help manage this condition effectively in Oculopharyngeal Muscular Dystrophy.

Oculopharyngeal Muscular Dystrophy is prominently seen in French Canadians and Jews living in Uzbekistan from Bukhara sect. The disease is less heard off amongst in Asians.

Duchenne muscular dystrophy

Duchenne muscular dystrophy is a form of muscular dystrophy that is linked to the X chromosome. It is the most common fatal inherited disorder that affects about 1 in every 3600 boys. It is characterized by muscle degeneration and weakness leading to impaired body movements. It almost always results in death.
Duchenne muscular dystrophy was named after a French neurologist Guillean Duchenne. It is also commonly referred to as DMD. He described a certain illness among a group of 13 boys who happened to have progressive muscle weakness.

G. Duchenne

Duchenne Muscular dystrophy named after G._Duchenne
via Wikimedia Commons by PawełMM

He observed that these boys were unable to walk later on. Most of them died. Guillean Duchenne described many forms of muscular dystrophy and the most severe form was actually named after him thus ‘Duchenne muscular dystrophy’.

Duchenne Muscular Dystrophy Inheritance

This disease is caused by a mutation or changes in the dystrophin gene. Dystrophin gene is the largest gene in the X chromosome of a human being. This gene codes for the protein dystrophin. This is a very important membrane protein that aids the structural stability of a muscle tissue. The changes occur in muscle fibers resulting in impaired muscle function. The defect may be transmitted by one parent in some conditions and by both in others.
About 35% of cases occur when there is no family history of muscular dystrophy. But as a result of high spontaneous mutation. The genetic defect could possibly exist in a family line without their knowledge. On the other hand there have been reports indicating that a whole new genetic mutation may occur in the cells of the mother ‘s egg.

Males normally have an X chromosome and a Y chromosome. Females have two X chromosomes. A male child obtains an X chromosome from their mother. He obtains a Y chromosome from their father. Similarly a female child inherits one X chromosome from their mother. Ans she obtains another X chromosome from her father.
A male child born to a woman with a mutation on the dystrophy gene on one of her X chromosomes ends up having a 50% chance of inheriting the mutated gene and may as a result suffer from muscular dystrophy. If the same woman were to give birth to a female child, the daughter has a 50% chance of inheriting the mutation on her X chromosome and will end up as a carrier. A carrier is an individual who does not suffer from the symptoms of the disease but can give birth to a baby who has the mutation.

Duchenne muscular dystrophy inheritance

Genetic inheritance for Duchenne muscular dystrophy


A male individual suffering from muscular dystrophy will not be able to pass the defective gene to his son because he only gives the Y chromosome to his male child. However he will definitely pass the gene to his daughter since a female child inherits her father’s only X chromosome. The daughter therefore becomes a carrier and her son has a 50% chance of developing DMD. This cycle continues throughout the family line.

Duchenne muscular dystrophy symptoms

Symptoms usually appear in childhood between ages 1-3. They begin with progressive weakening of the muscles of the limbs. Later on the patient begins to suffer from muscle wasting , abnormal bone development, skeletal deformities and resultant loss of movement. Eventually this may lead to paralysis. The average life expectancy for children with DMD is about 25 years.
Diagnosing this condition may be quite difficult as the symptoms vary from patient to patient. Laboratory tests include measurement of creatinine phosphokinase (CK) which is known to leak in large amounts from damaged muscles. Genetic testing and muscle biopsy will show absence of the protein dystrophin.
Medical treatments to slow down the symptoms of this disease have been explored. The results are good only to the extent of prolonging life to some extent.But there is currently not many options for treatment of Duchenne muscular dystrophy.

REFERENCES

  1. 1. 1: Emery AE. The muscular dystrophies. Lancet. 2002 Feb 23;359(9307):687-95.Review. Pub Med PMID: 11879882. 2. 1: Hsu YD. Muscular dystrophy: from pathogenesis to strategy. Acta Neurol Taiwan.2004 Jun;13(2):50-8. Review. Pub Med PMID: 15478675.
  2. http://mda.org/disease/duchenne-muscular-dystrophy
  3. http://www.nlm.nih.gov/medlineplus/ency/article/000705.htm

Duchenne muscular dystrophy prognosis.

Duchenne muscular dystrophy prognosis is not so encouraging.
Duchenne muscular dystrophy (DMD) is characterized by progressive muscle weakness that results in disability. Death usually results at around the age of 25 years, mostly from lung disorder.

The family of the patient hearing the diagnosis for the first time might hear the news as a kind of blow to their personal life.
Duchenne muscular dystrophy prognosis indicates death at around the age of 20 to 25.

Fatal complications

Duchenne muscular dystrophy prognosis indicates several fatal complications. They range from cardiomyopathies, congestive heart failure deformities and pneumonia. It could also result in respiratory infections, permanent disability and even mental impairment.
In early stages of the disease, Duchenne muscular dystrophy prognosis indicates that the children with duchenne muscular dystrophy may be able to walk run or even play with their peers. But they will show considerable signs of difficulty.

Duchenne Muscular Dystrophy prognosis

Duchenne Muscular Dystrophy prognosis


As the condition progresses, function of the lower limbs worsen. They will need a wheel chair .
Further progression of this condition results in loss of function in the upper limbs. Breathing difficulties may be seen in the last stages of the disease.
It shortens the life expectancy. However with the current trends in medical research, management of this condition has improved. There are cases of patients living longer than the suggested 25 years.

Duchenne muscular dystrophy multiple complications

Several problems have been associated with Duchenne muscular dystrophy:

  1. Respiratory Function: Gradual loss in lung function due to weakening of the respiratory muscles. Eventual respiratory difficulties are seen when the patient becomes immobile due to wheelchair confinement. It is important for patients to have regular assessment by respiratory specialists.
  2. Learning Difficulties : About 35% of patients with Duchenne muscular dystrophy experience learning difficulties. This is however not progressive and can be corrected with good help.
  3. Pain and Sensation: Weakening of muscles is not associated with pain but patients with Duchenne muscular dystrophy may experience muscle cramping or pain due to postural problems.
  4. Heart problems: Duchenne muscular dystrophy can affect the heart in two ways:
  • Through damage of the muscle fibers of the heart(conducting tissue) resulting in abnormal heart rhythm. This may manifest through palpitations, dizzy spells or black outs.
  • Cardiomyopathy- This is abnormal pumping action of the heart. This will manifests through breathlessness. Regular cardiac function checks are important for patients with Duchenne muscular dystrophy. Studies reveal that female carriers also exhibit signs of Cardiomyopathy.

To date, there is no cure for Duchenne muscular dystrophy but a tremendous amount of research is being conducted across the world. Valuable insights on this condition have been obtained as a result of research. Families of those that suffer from this condition can now join various forums. They can receive support from organizations that have been established for this purpose.

Emphasis has been placed on genetic counseling for families who are affected or are at risk of being carriers. They are provided with information on inheritance patterns, risks involved and disease prognosis. Advice to explore family planning options or new technology such as genetic diagnosis is given.

Measures have been put in place to improve the quality of life.
General Duchenne muscular dystrophy prognosis has improved over the years because of the focus of research in improving the lives of the patients. Areas being researched for DMD include:

  • Exon skipping involves introduction of molecular patches that work on the gene parts that contain mutation.This method tries to repair the Dystrophin protien as to make DMD less severe than what DMD at the moment actually is. Results from this research are promising.If this is further successful, it could help almost 50% of DMD patients.
  • Gene therapy is aimed at introducing a healthy synthetic copy of the Dystrophic gene into the muscles so that the Dystrophin protein could get made. This has been challenging but modifications are being looked into.
  • Stem cell therapy is a procedure that involves introduction of donor cells into damaged muscle in the hope that they will fuse with that affected muscle to create healthy fibers. Good results have been obtained with animal studies. But there have been challenges of immune responses. The safety and benefit of stem cell treatment on Humans has not been tested.
  • Various drugs are currently being investigated in their ability to treat the symptoms of DMD. These also try to repair the damaged muscles and inhibit formation of scar tissue.

 

REFERENCES

1. 1: Emery AE. The muscular dystrophies. Lancet. 2002 Feb 23;359(9307):687-95.Review. PubMed PMID: 11879882. 2. 1: Hsu YD. Muscular dystrophy: from pathogenesis to strategy. Acta Neurol Taiwan.2004 Jun;13(2):50-8. Review. PubMed PMID: 15478675.

  1. MDA.org
  2. US National Library of medicine

Duchenne Muscular Dystrophy treatment

Total annual cost of Duchenne Muscular Dystrophy treatment as per MDA.org is around fifty two thousand annually.
This includes Medical costs of around $22500, non medical costs of around $13000 and lost income of $15500.
Duchenne muscular dystrophy is a hereditary muscle disorder characterized by gradual weakening of the muscles resulting in loss of locomotion. To date, there is no cure for Duchenne muscular dystrophy. Duchenne Muscular dystrophy treatment options being explored are aimed at managing the condition and improving the quality of lives of the patients.

Duchenne Muscular Dystrophy patient management

Several management techniques have been put in place. The main ones are medical treatment, surgery, physical therapy and occupational therapy.

Duchenne Muscular Dystrophy medical treatment

Patients with Duchenne muscular dystrophy are prescribed steroid drugs which slow down the rate of muscle deterioration .Other treatments are aimed at relieving symptoms as they occur. These include albuterol anti asthma drug, cod liver oil, amino acids, creatinine and vitamin E supplements. Heart function could be aided with drugs such as Angiotensin converting enzyme inhibitor, beta blockers and diuretics. Effects of most of these treatments are yet to be proven. Stem cells and gene therapy are being explored for future use.

Find here an helpful resource related muscular dystrophy life expectancy: http://www.muscleatrophy.net/muscular-dystrophy/muscular-dystrophy-life-expectancy-2/

Surgery for Duchenne muscular dystrophy Treatment

Surgery may be required in certain cases to release contractures or tightness at the ankle joints for this muscular dystrophy. This is true particularly for patients who are wheel chair dependent. Scoliosis – curvature of the spine may also be corrected by surgery as it may cause respiratory complications.

Assisted ventilation for Duchenne muscular dystrophy Treatment

Assisted ventilation is a common intervention for patients with DMD particularly at night. As this is when respiratory problems occur. Patients with advanced stages of the disease may require mechanical ventilation throughout.

Assisted ventilation for DMD. The Iron Lung ward at Rancho Los Amigos Hospital.

Assisted ventilation for DMD
The Iron Lung ward at Rancho Los Amigos Hospital

Physical Therapy for Duchenne muscular dystrophy Treatment

This is aimed at ensuring the children reach their maximum physical potential. Physical exercises are very important. They help the patients to minimize development of deformities or contractures. They also prevent secondary complications and aid respiratory function.

Occupational therapy for Duchenne muscular dystrophy Treatment

Occupational therapy involves ensuring the patient gets into some activities. This is simply to improve the quality of their lives. This also contributes to their ability to conduct self care activities and at the same time improve their productivity and leisure. Occupational therapists address the limitations of the patients through the use of the following resources:

  • Splinting: Splints are supportive devices that are designed to improve or maintain a desired range of motion in a limb. This is done by supporting the limbs and keeping them stretched. This prevents deformity or contractures.
  • Splints supportive devices for Duchenne Muscular Dystrophy

    Splinting
    By Becguglielmino (Own work) [CC-BY-SA-3.0], via Wikimedia Commons

  • Manual Muscle Testing is a technique used to evaluate the strength of a muscle therefore determining whether the muscle needs intervention such as splinting.
  • Seating and positioning: This is necessary to prevent spinal curvatures and scoliosis. This is a common occurrence in Duchenne muscular dystrophy. Modified wheel chairs are normally used for this purpose.
  • Adaptive equipment and devices may also be prescribed to act a mobility aids. These include walkers, quad canes. Normal household devices such as shower heads and toilets chairs. Computers may also be modified to ensure that DMD patients are able to perform their own self care needs
  • Development of social skills: Individuals suffering from DMD usually have social issues that need to be overcome. Occupational therapists have developed individualized programs as well as group sessions to enhance development of essential social skills. It is believed that building of one’s self esteem is an essential part of improving the quality of their lives. Specific psychological issues encountered also need to be sorted.
  • Sexual health: Although, it is a topic that is not given a lot of importance. Patients need to be advised on safe and effective ways to experience their sexual life.
  • Advocacy: An occupational therapist should act as an advocate for their patient. He can do this best by providing relevant information to the patients. This could be about their illness, support, resources and major concerns. It is also necessary to provide the client with their own tools for advocacy.

References
Kornegay JN, Spurney CF, Nghiem PP, Brinkmeyer-Langford CL, Hoffman EP, Nagaraju K. Pharmacologic management of Duchenne muscular dystrophy: target identification and preclinical trials. ILAR J. 2014;55(1):119-49. doi:10.1093/ilar/ilu011. PubMed PMID: 24936034; PubMed Central PMCID: PMC4158345.

2: Landfeldt E, Lindgren P, Bell CF, Schmitt C, Guglieri M, Straub V, Lochmüller H, Bushby K. The burden of Duchenne muscular dystrophy: an international, cross-sectional study. Neurology. 2014 Aug 5;83(6):529-36. doi:10.1212/WNL.0000000000000669. Epub 2014 Jul 2. PubMed PMID: 24991029; PubMed Central PMCID: PMC4141999.

3: Fujak A, Haaker G, Funk J. [Current care strategies for Duchenne muscular dystrophy]. Orthopade. 2014 Jul;43(7):636-42. doi: 10.1007/s00132-013-2217-7.German. PubMed PMID: 24906240.

4: http://www.genome.gov/19518854

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