Muscle Disorders

Original Editor - Elaine Lonnemann

Top Contributors -Andeela Hafeez, Kim Jackson, Rucha Gadgil, Elaine Lonnemann, Evelin Milev, Admin, Lucinda hampton, 127.0.0.1, Wendy Walker, Evan Thomas, Anil pratap tanwar, Vidya Acharya and Amrita Patro  

Introduction

Muscle Disorders are the diseases and disorders that affect the human muscle system and their main manifestation is skeletal muscle weakness. The terms ‘muscular dystrophy’, ‘neuromuscular conditions’ and ‘neuromuscular disorders’ fall under the umbrella of the term 'Muscle Disorders'. These disorders are 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. Disorders of muscle may cause weakness or paralysis in the presence of an intact nervous system. 

Classification

Muscle disorders can be classified on the basis of :

1. Primary or secondary : Diseases and disorders as a result of direct abnormalities of the muscles are considered primary muscle diseases, Eg. Polymyositis. And Diseases that are secondary to another condition and may have caused muscle damage, Eg. diseases due to endocrine issues .
2. Genetic or Acquired
3. Neuromuscular or Myopathies

Etiology

Causes of muscle disorders include:

• Age, hereditary
• 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
• Metabolic causes and Endocrine causes
• Autoimmune disorders
• Etiology may not be known at times

Symptoms

Symptoms vary with the different types of muscular disorder.

Symptoms may include:

1. Muscle weakness that slowly gets worse.
2. breathing issues, especially dyspnea (shortness of breath)
3. dizziness,
4. Fatigue
5. Muscle wasting, loss of strength
6. high fever,
7. a stiff neck. 
8. Numbness, tingling, or painful sensations
9. Double vision
10. Droopy eyelids
11. Problems with swallowing—dysphagia
12. Difficulty using one or more muscle groups, muscle weakness,
13. Problems walking, balance and frequent falls

Types Of Muscle Disorders

Common types of Muscle Disorders include:

1. Muscular dystrophy: It is a group of genetic/ 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.
   • 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. A study demonstrates the use of a holistic approach in the initial stage while reaching a diagnosis of Limb girdle muscular dystrophy is important. The biopsychosocial model, myotome testing, creatine kinase testing and MRI (results showed paraspinal atrophy) highlighted the Limb girdle muscular dystrophy diagnosis which was missed on normal physiotherapy assessment. The case report suggests the need of appropriate testing to rule out differential diagnoses.
   • 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.
2. Cramp: prolong painful involuntary contraction of skeletal muscles
3. Fibrositis: Inflammation of fibrous connective tissues in muscles.it also effect muscles of trunk and back.
4. Polymyositis
5. Myasthenia Gravis
6. Rhabdomyolysis
7. Dermatomyositis
8. Cardiac Myopathy: Cardiomyopathy­—also called heart muscle disease—is a type of progressive disease affecting cardiac muscle.
9. Amyotrophic Lateral Sclerosis
10. Sarcopenia: This muscle disease can be primary or secondary. Sarcopenia causes muscle mass loss and muscle strength loss.

Diagnosis:

Usually it is first suspected because of symptoms: a muscle weakness is noticed by the patient, family or a doctor.

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

1. An electromyography (EMG) - this is a recording of the electrical activity in a muscle. It can diagnose muscle disorders, nerve and motor problems, and degenerative diseases.
2. A blood test : measuring specific muscle enzymes and antibodies that may be specific to one disorder or many
3. 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.
4. Genetic analysis - this involves testing a person's DNA using a blood sample. It can detect many (not all) cases of MD.
5. MRI: to show abnormal muscle areas
6. Muscle ultrasound is used to look for suspected CMD.

Treatment:

There is currently no cure for muscular disorders, but a variety of treatments can help manage the condition. 

The goals of treatment for muscle diseases may include:

1. treating symptoms,
2. delaying disease progression, and
3. improving quality of life.

Medical Management:

Corticosteroids taken by mouth are sometimes prescribed for reducing cramping and spasms. Immunosuppressants—drugs inhibit or prevent the overactivity of the immune system—may be given for some muscle and nerve diseases, and conditions that affect both the nerves and muscles.

Surgical corrections may be advised if needed.

The person should be as active as possible. Complete inactivity (such as bedrest) can make the disease worse.

Physiotherapy Management

The physical therapist is part of multidisciplinary team and management of such disorders is long-term.

The Physical therapy goals may include:

• Strengthening programme
• Pain Management
• Management of contractures: stretching, exercises and night splints, if required
• Swimming and hydrotherapy
• Arranging home adaptations
• Cardiac and Respiratory Rehabilitation programme
• Balance training