Neuro Muscular Dystrophy

Neuro Muscular Dystrophy diseases are rare acquired or inherited (genetic) conditions that affect some part of the neuro muscular system such as:

  1. Muscles

  2. Peripheral motor nerves (in arms, legs, neck and face)

  3. Neuromuscular junction where the nerves and muscles meet

  4. Muscle-controlling nerve cells (motor neurons) in the spinal cord

  5. More than a million people in the United States are affected by some form of neuromuscular disease, and about 40 percent of them are under age 18.

All neuro muscular diseases are progressive in nature, and all result in muscle weakness and fatigue. Some diseases are present at birth, some manifest in childhood, and others have an adult onset. The disease may be passed down through family genetic lines, and in some cases the student may have an affected sibling, parent or other relative. At other times there isn’t a family history and the disease is the result of a spontaneous genetic mutation, an abnormal immune response or an unknown cause.

Life expectancy varies by disease and severity, from very short to normal length. Heart and respiratory problems, which are secondary effects of muscle deterioration, often are the cause of death.

Although muscle wasting isn’t painful, the resultant weakness can cause cramping, stiffness, joint deformities, chronic aches and pain, and sometimes the tightening and freezing of joints (contractures).

In almost everyone with a neuromuscular disease, bladder and bowel control are normal, although students may need help in the bathroom as their physical abilities weaken. Sexual functioning and skin sensation usually are normal. Strengthening exercises don’t prevent muscle decline in neuromuscular diseases, and in some cases can further damage fragile muscle cells if done too vigorously. Moderate and light exercise or standing exercises, undertaken under the guidance of a physical therapist (PT) or doctor, may help maintain muscle tone and flexibility, as well as combat obesity and bone thinning. Be sure a doctor or PT has approved your student’s exercise plan.

 

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Symptoms

Neuromuscular disease can be caused by circulatory problems (stroke, etc.), immunological and autoimmune disorders, the failure of the electrical insulation surrounding nerves myelin, genetic/hereditary disorders, such as Huntington’s disease, certain rare tumors, the failure of the connections between the nerves and the muscle fibers, exposure to pernicious environmental chemicals, poisoning (including heavy metal poisoning), and importantly, unknown causes. The failure of the electrical insulation surrounding nerves, the myelin, is seen in certain deficiency diseases, such as the failure of the body’s system for absorbing vitamin B-12, and also the failure of the myelin is seen in multiple sclerosis and some other neurological diseases, especially in autoimmune diseases that are thought to attack the myelin.

Myopathies are all diseases primarily resulting in muscular degeneration, rather than affecting the nerves themselves. Muscular dystrophies, including Duchenne’s and Becker’s, are a large group of diseases, many of them hereditary or resulting from genetic mutations, where the muscle integrity is disrupted. They lead to progressive loss of strength and decreased life span.

Symptoms of muscle disease may include muscular weakness, rigidity, loss of muscular control, myoclonus (twitching, spasming), and myalgia (muscle pain). Diagnostic procedures that may reveal muscular disorders include direct clinical observations. This usually starts with the observation of bulk, possible atrophy or loss of muscle tone. Neuromuscular disease can also be diagnosed by testing the levels of various chemicals and antigens in the blood, and electromyography (measuring electrical activity in muscles). Diagnostic imaging may be helpful in certain cases, such as those caused by strokes or tumors.

Resources

Resources

  • Khoshknabi DS. Muscle spasms. In: Walsh D, Caraceni AT, Fainsinger R, et al, eds. Palliative Medicine. 1st ed. Philadelphia, Pa: Saunders Elsevier;2008:chap 168.
  • Griggs RC, Jazefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 418.

Treatments

Nutritional support – When the muscles used in swallowing and chewing are weakened, there’s a risk of dehydration, malnutrition, choking or respiratory infections caused by inhaling food or liquid into the lungs (aspiration).

Gastrostomy tube (g-tube, feeding tube or PEG) is a tube permanently placed through the stomach wall, so a liquefied diet can be fed directly into the stomach. Those who use a g-tube because eating is difficult and time-consuming still can have food and drink by mouth for pleasure and extra nutrition. But those who use a tube because of choking and aspiration probably shouldn’t eat anything by mouth.

Physical and occupational therapy

Keeping the body flexible, upright and mobile combats some of the side effects of neuromuscular disease. Such therapy also benefits academic performance by allowing children to do more and stay healthier. Your student’s IEP may specify that a certain time must be set aside each day for him or her to work with a physical or occupational therapist. PT or OT interventions include:

Range-of-motion exercises and stretches prevent contractures or freezing of the joints of the knees, hips, feet, elbows, wrists and fingers. Hand splints keep the wrists and fingers in a good position.

Swimming pool exercise, especially in a warm pool, is often easier for children with weak muscles.

Proper body mechanics ensure safe transfers of nonambulatory students by aides, teachers and other caregivers, so neither party gets hurt.

Although only a few drugs are approved for use against the effects of neuromuscular disease, ongoing clinical trials are constantly seeking to expand that number.  One medication that has proven effective in some neuromuscular diseases is prednisone. This steroid may be taken by children with Duchenne muscular dystrophy (DMD) and some other neuromuscular conditions because it slows the loss of muscle function and increases muscle strength, providing for a few more months to a few more years of leg and arm use. Prednisone’s undesirable side effects include weight gain, loss of bone mass, thinning of the skin, raised blood pressure and blood sugar, depression, and difficulties with thinking, sleeping and controlling behavior.  It’s important to carefully monitor the diets of children on prednisone, and to be aware of its behavioral effects.

When weak respiratory muscles make it difficult to effectively move air in and out of the lungs, children may experience headaches, mental dullness, difficulty concentrating or staying awake, and nightmares. In addition, weak chest muscles make it hard to cough effectively, leaving the lungs more susceptible to infection. In some children, a simple cold can rapidly progress into pneumonia.

Assisted ventilation: Help with breathing may be given either through an external mask or “sipper” tube, or by way of a tracheostomy, in which a tube is inserted directly into the airway to deliver air to the lungs. Cough assist machines: These machines help bring up lung secretions to keep the bronchial system free of infection.

Heel cord and foot joint surgeries are used to treat ankle contractures and joint deformities in order to prolong walking. Students usually are out of school less than two weeks.

Scoliosis surgery is performed on older children and adolescents with serious spinal curvature. Timing of the surgery hinges on the student’s growth, lung function, discomfort level and how fast the curve is worsening. Metal rods with hooks are inserted into the spine, and students can spend 6 to 10 weeks out of school. (When possible, these surgeries are scheduled during the summer.)

After scoliosis surgery, students sit much straighter and have fewer problems with breathing. They often require a new wheelchair and adjustments in classroom desk height. Unfortunately, some abilities, such as reaching, may be negatively affected by this surgery.

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