Muscle Disorders


Descripation:

The terms ’muscle disease’, ‘muscular dystrophy’, ‘neuromuscular conditions’ and ‘neuromuscular disorders’ all describe a large group of conditions which affect either the muscles, such as those in the arms and legs or heart and lungs, or the nerves which control the muscles[1]. Muscle disease include a number of rare conditions, which in most cases tend to present at around the same age and due to the their progressive character they can lead to physical limitations and reduced life expectancy.

Causes:

Causes of muscle disorders include[2]:

  • Injury or overuse, such as sprains or strains, cramps or tendinitis
  • A genetic disorder, such as muscular dystrophy
  • Some cancers
  • Inflammation, such as myositis
  • Diseases of nerves that affect Muscle
  • Infectious Diseases
  • Certain medicines

Sometimes the cause is not known.

Symptoms:

Symptoms vary with the different types of muscular dystrophy.
All of the muscles may be affected. Or, only specific groups of muscles may be affected, such as those around the pelvis, shoulder, or face. Muscular dystrophy can affect adults, but the more severe forms tend to occur in early childhood.


Symptoms include:
Intellectual disability (only present in some types of the condition)
Muscle weakness that slowly gets worse
Delayed development of muscle motor skills
Difficulty using one or more muscle groups
Drooling
Eyelid drooping (ptosis)
Frequent falls
Loss of strength in a muscle or group of muscles as an adult
Loss in muscle size
Problems walking (delayed walking)[3]

Types:

Muscular dystrophy is a group of inherited diseases that are characterized by weakness and wasting away of muscle tissue, with or without the breakdown of nerve tissue. There are nine types of muscular dystrophy, with each type involving an eventual loss of strength, increasing disability, and possible deformity[4].

The most well known of the muscular dystrophies is Duchenne muscular dystrophy (DMD),presently no cure, it occurs genetically, most commonly in children by his/her mother and is the most severe of all the muscular dystrophies. The symptoms first present in 3 to 5 years of age, as progressively joints become stiff and muscles power is lost. Thus, DMD is characterised as severe life-limiting disease requiring multi-disciplinary intervention and life-long management.

Becker:Symptoms are almost identical to Duchenne but condition is milder and progresses more slowly; survival into middle age.

Congenital:Symptoms include general muscle weakness and possible joint deformities; disease progresses slowly; shortened life span.

Distal:Symptoms include weakness and wasting of muscles of the hands, forearms, and lower legs; progression is slow; rarely leads to total incapacity.

Limb-Girdle:Symptoms include weakness and wasting, affecting shoulder girdle and pelvic girdle first; progression is slow; death is usually due to cardiopulmonary complications.

Myotonic: Symptoms include weakness of all muscle groups accompanied by delayed relaxation of muscles after contraction; affects face, feet, hands, and neck first; progression is slow, sometimes spanning 50 to 60 years.

Atrophy: Spinal Muscular Atrophy is the most common type of muscular atrophies. Several types of the disease are known. More information about SMA can be found here.

Cramp: prolong painful involuntary contraction of skeletal muscles.

Fibrositis: Inflammation of fibrous connective tissues in muscles.it also effect muscles of trunk and back.[5]

Diagnosis:

Usually it is first suspected because of symptoms: a muscle weakness is noticed by the patient, family or a doctor. Also, if a child has delayed motor milestones (as mentioned above), a doctor may advise testing for MD, even though the problem could be due to another cause.[6]

MD may be diagnosed using one or more of the following tests:

A blood test for creatine kinase (CK) - in many types of MD, the blood level of CK is very high.
A muscle biopsy - this involves taking a small sample of muscle under local anaesthetic. The sample is examined under the microscope and the muscle chemicals (proteins) may be tested.
Genetic analysis - this involves testing a person's DNA using a blood sample. It can detect many (not all) cases of MD.
An electromyogram (EMG) - this is a recording of the electrical activity in a muscle.
Muscle ultrasound is used to look for suspected CMD.

Treatment:

There is currently no cure for muscular dystrophy (MD), but a variety of treatments can help manage the condition.[7] low-impact exercise, such as swimming
physiotherapy can be useful for maintaining muscle strength, preserving flexibility and preventing stiff joints
physical aids, such as a wheelchair, leg braces or crutches, can help you maintain standing and stay mobile.

Corticosteroids taken by mouth are sometimes prescribed to children to keep them walking for as long as possible.
The person should be as active as possible. Complete inactivity (such as bedrest) can make the disease worse.[8]

Management

General management

  • Arranging home adaptations
  • Management of contractures: stretching, exercises and night splints.
  • Corticosteroids
  • Swimming and hydrotherapy
  • Surgical corrections

Respiratory and Cardiac problems

With advancing age, respiratory and cardiac problems will become inevitable and if not recognised early, can become cause of death. Muscle weakness can affect the intercostal and diaphragmatic muscles, and thus the a reduction in vital capacities are expected. Some of the symptoms are chest wall stiffness, recurrent aspiration and inability to cough. There is evidence that nocturnal ventilation and spinal surgery further improve survival[9].

Prevention:

Genetic counseling is advised when there is a family history of muscular dystrophy. Women may have no symptoms but still carry the gene for the disorder. Duchenne muscular dystrophy can be detected with about 95% accuracy by genetic studies performed during pregnancy[3]


Reference:

  1. http://www.muscular-dystrophy.org/newly_diagnosed/about_muscle_disease/545_what_is_muscle_disease
  2. A service of the U.S. National Library of Medicine. From the National Institutes of HealthNational Institutes of Health http://www.nlm.nih.gov/medlineplus/muscledisorders.html
  3. 3.0 3.1 Sarnat HB. Muscular dystrophies. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics . 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 601.
  4. http://uhealthsystem.com/health-library/neuro/disorder/muscular/musctype
  5. ivyrose holistic http://www.ivy-rose.co.uk/HumanBody/Muscles/Muscular_Disorders.php
  6. Individual & Caretaker Workbook Simple and Easy Instructionshttp://myhealth.patient.co.uk/
  7. http://www.nhs.uk/Conditions/Muscular-dystrophy/Pages/Treatment.aspx
  8. Bushby RF, Birnkrant DJ, Case LE, Clemens PR, Cripe L, Kaul A, et al. Diagnosis and management of Duchenne muscular dystrophy. Lancet Neurol . 2010;9:77-93. http://www.nytimes.com/health/guides/disease/muscular-dystrophy/overview.html
  9. Eagle et al., 2007 Managing duchenne muscular dystrophy - the additive effect of spinal surgery and home ventilation in improving survival.