Generally, there are various genetical conditions that can tremendously affect growth, development and quality of survival or daily living. Muscular dystrophies (MD)is a group of inherited or genetic diseases that affect susceptible individuals with positive family history of certain defected genes, leading to muscular weakness as a result of damaged fibers.
What Is Muscular Dystrophy
Muscular dystrophy is a progressive genetic condition that increases the vulnerability of muscle fibers to damages, degeneration and destruction. In most cases, affected individuals become handicapped eventually. So far 30 different muscular conditions have been identified clinically (that have similar etiological mode of occurrence, there is to say, inheritance of defected gene that control muscle metabolism).
5 Common Types Of Muscular Dystrophy
As discussed previously, there are over 30 different types of muscular dystrophy. However, some are more common in terms of occurrence when compared to others. A brief review of each type is discussed below:
- Congenital muscular dystrophy
In congenital muscular dystrophy, the sign and symptoms of muscle defects are reported soon after the childbirth. The babies have floppy muscles and weak motor activity along with varying degrees of mental retardation, epilepsy and visual abnormalities (1). According to the latest research authored by Tome (2), it was identified that an inherited defect at chromosome 9 is associated with congenital muscular dystrophy. Besides being the commonest muscular dystrophy in children, it is one of the aggressive and severe forms too that is highly prevalent in Japan (also known as Fukuyama congenital muscular dystrophy). Other classic features are:
- On biopsy, increase in the concentration of endomysial collagen tissue is reported.
- Research conducted by Tome (2) on 13 patients suggested a possible deficiency of merosin chain (a muscle fiber component). J. Philpot (3) suggested that merosin deficiency is also associated with worst prognosis with almost 20% patients (or 2 of every 10 patients) die in the first few years of life due to severe changes or alterations in the white matter of brain.
- N Spyrou (3) suggests that the overall incidence of this form of muscular dystrophy is 1 in 10,000, with appearance of symptoms at birth (hypotonia of muscles) and full- blown disease by 6 month of age.
- Distal muscular dystrophy
This is a peripheral form of muscular dystrophy in which only peripheries are involved (muscle loss and motor deficits of hands, fore-arms, legs and feet). It has an autosomal recessive patter of inheritance and considerable new form of myopathy (with only 17 cases reported in the literature so far). Research conducted by Kazuo Miyoshi (13) suggested widespread areas of necrosis in muscle fibers followed by partial regenerative changes. In autopsy of all 17 patients, no brain or spinal cord lesion was reported suggesting a pure muscular pathological illness.
- Duchenne muscular dystrophy
This is by far the most common variety of muscular dystrophy and is associated with a worst prognosis due to high risk of involvement of respiratory muscles. The primary defect in this type of dystrophy is the lack of a protein (dystrophin) in the muscle fibers due to an inherent X-linked defect (5).
- Oculopharyngeal muscular dystrophy
As the name suggests, the primary abnormality in this type of muscular dystrophy (10) is weakness of ocular and oral muscles that present with drooping of eye-lids and visual difficulties (like double vision), progressive involvement of muscles of oral cavity and throat (leading to difficulty in mastication, swallowing and breathing). Unlike most other varieties of muscular dystrophies, the sign and symptoms usually appear in late adulthood (mid-40s to 50s). As suggested by Brias (10), the microscopic study of skeletal muscle fibers is diagnostic (with the key feature of intranuclear filament inclusions).
- Fascioscapulohumeral muscular dystrophy (FSHD)
The key feature is prominent shoulder blade that becomes more evident with upper limb elevation. The onset is usually in early teens (11). It has an autosomal pattern of inheritance with restricted presentation (involving only leg or hip girdle). In later stages of illness, almost 20% patients develop moderate disability leading to wheelchair dependency. Patients also develop retinal telangiectasias and hearing loss. Other common varieties include Becker muscular dystrophy, myotonic muscular dystrophy and limb-girdle muscular dystrophy.
What Are The Primary Symptoms Of Muscular Dystrophy?
The age of onset of muscular dystrophy symptoms is dependent upon the type of inherited defect. For example, in childhood onset muscular dystrophy the symptoms may plead at an age as early as 10 to 12 years. But in other cases, symptoms may remain unnoticed until adulthood. The classic symptoms of muscular dystrophy are:
- Progressive loss of muscle mass that manifests itself as weakness of limbs and incapable to perform normal daily activities like standing up from sitting position, running or jumping.
- Progressive difficulties in the breathing and swallowing that increases morbidity.
- Weakening of heart muscle that leads to rhythm and conduction abnormalities.
- Atrophy of large groups of muscles like calf muscles, biceps and others.
Generally, muscular dystrophy is not linked with any environmental, physical or metabolic risk factors. However, research indicates a positive family history increases the risk of inheritance in young boys almost 25-folds.
How To Manage Muscular Dystrophy?
Despite the ongoing research efforts and medical advancements, there is no cure or curative therapy devised for muscular dystrophy till now. However, there are various treatment options that can slow down the progression of disease symptoms. The following treatment modalities are most commonly employed for the management of muscular dystrophy:
- Steroids therapy
In cases of acute exacerbation or aggravation of symptoms, steroids therapy may be administered to reduce the degree of muscular damage and improve the stability of joints. However, do exercise caution if you are put under this treatment. This is to avoid over-consumption or prolonged administration of steroid therapy due to risk of osteoporosis and steroid tolerance (that further increases the risk of bone damage).
- Stretching exercises
Muscular dystrophy affects the mobility and range of motion of large joints and muscle groups. Due to muscular weakness, the limbs assume abnormal positions due to uninterrupted pull of opposite group of muscles. (for example flexor position when extensor group of muscles suffer more damage and destruction as compared to flexor group of muscles and vice versa)
- Surgical intervention
Surgeries are attempted to improve the quality of life in situations when the muscular dystrophy affects systems and organs that are vital to the survival. For example, surgical correction of scoliosis is needed if the altered spinal curvature interferes with breathing. Similarly, surgeries are also performed to release tendons that are affecting the joint or limb activity.
Fast Facts On Interventional Therapies
A lot of research and experimental study has been conducted by healthcare providers and scientists to devise therapeutic options to manage muscular dystrophy. However, there are a number of limitations.
In vast majority of animal studies, the transfer of myoblasts yielded promising results. The technique involves introduction of skeletal muscle fibers via injection in the recipient. The donor muscle fibers are capable of cross-linking with recipient muscle fibers (that lack dystrophin) and function as a normal unit. However, in order to eliminate the immune response against host cells, immuno-suppression is required. (6)
The research conducted by Tremblay (4) suggested that gene therapy (that is considered an interventional therapy with fairly positive outcomes) is not possible without immuno-suppressions. Similarly, when he attempted muscle transplantation in 5 young boys who have dystophin positive disease, the results were not encouraging in the absence of immuno-suppression that most healthcare providers avoid unless extremely important.
Even with immuno-suppression, the results are mixed and unreliable. In study conducted by Gussoni (7) and Karpati (8), no noticeable improvement was reported in muscle strength and stability after therapy. However, Huard (9) and Law (6) suggested that improvement in the muscular activity and strength can be achieved if anti-inflammatory agents like prednisone and cyclosporine are used in addition to myoblast transfer and immuno-suppression.
Gene therapy for muscular dystrophy is also becoming very popular for management of muscular dystrophy. However, the setback is till now, promising results are not reported yet.
Alternative Treatments For Muscular Dystrophy
Muscular dystrophy can be managed by alternative medicine and holistic methods of care. The 2 main alternative treatment options are as below:
- Coping groups
Muscular dystrophy is a progressive condition in which symptoms worsen with advancing age. The degree of physical dependence directly affects the psychological health and may lead to emotional instability. It is therefore recommended by healthcare providers to join coping groups to learn more about the suffering of other people and adaptive strategies.
The high morbidity and mortality due to muscular dystrophy is attributed to respiratory difficulties that follow progressive muscle damage. It is recommended to stay up to date on all your vaccinations (especially pneumonia vaccine and annual influenza shots) to prevent the risk of any infection.
- Mobility aids
In order to retain full functional independence of large muscle groups, mobility aids like walkers, sticks and similar assisting devices are fairly helpful. In earlier course of illness you can also use especially designed corsets or braces to support your physical architecture. In addition, since weakening of respiratory muscles is one of the commonest complications observed in the setting of muscular dystrophy, attempt should be made to start the use of sleep apnea device to prevent any unlikely event.
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