Muscular System Diseases and Disorders
Muscular System Diseases and Disorders
Learning Objective: Examine muscular diseases and disorders, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Diseases and disorders of the muscular system often involve other body systems, including the skeletal and nervous systems. Common signs and symptoms of muscular disorders include the following:
• Swelling in the joints and muscles
• Malaise (generalized weakness or discomfort)
• Myalgia (muscle pain), myositis (inflammation of a muscle), and muscle tenderness
• Temporary loss of function or loss of normal mobility
The following sections address common muscular system disorders.
Compartment Syndrome
Learning Objective: Discuss compartment syndrome, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Compartment syndrome is a serious condition that can occur after a traumatic injury. Increased pressure is applied to muscle compartments, leading to muscle and nerve damage.
Fascia separates groups of muscles. Inside each fascial layer is a compartment space that contains muscle tissue, nerves, and blood vessels. Swelling in the compartment space will lead to increased pressure in the area because the fascia does not expand. Increased pressure can cause an interruption in the blood flow to the area, leading to muscle death.
Acute compartment syndrome can be caused by a fracture, bruised muscle, severe sprain, or a crushing injury. This condition can also occur if a cast or bandage is too tight. Chronic compartment syndrome is caused by repetitive activities, such as running. Compartment syndrome can cause pale skin, swelling, severe pain, and inability to move the extremity. The person may experience a decrease in sensation, numbness, tingling, or weakness in the extremity.
After an exam, the provider may need to measure the compartment’s pressure. A needle attached to a pressure meter is inserted into the compartment. Treatment includes immediate surgery (fasciotomy) to prevent permanent damage. An incision is made in the fascia and muscle to relieve the pressure. With prompt treatment, the prognosis is good. If treatment is delayed, permanent muscle loss and nerve injury can occur.
Fibromyalgia
Learning Objective: Discuss fibromyalgia, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Fibromyalgia causes muscle pain, fatigue, and “tender points” on the legs, hips, back, arms, shoulders, and neck. It is estimated that 10 million people in the United States have fibromyalgia. Women develop fibromyalgia more often than men. Usually, the diagnosis occurs before age 50.
The etiology is unknown. Research indicates that trauma, infection, or injury may change how the central nervous system (CNS) responds to pain, leading to chronic pain. The signs and symptoms of fibromyalgia include widespread muscle pain, burning, aching, stiffness, or soreness. Additional symptoms include fatigue, sleep disturbances, mood and concentration problems, anxiety, headache, abdominal pain, bloating, constipation, diarrhea, bladder spasms, dizziness, numbness or tingling in the hands and feet, and tender points around the body.
The provider will perform an examination and rule out other conditions. With no diagnostic tests for fibromyalgia, the provider may use these results:
• Widespread Pain Index (WPI) score, which evaluates 19 areas of the body for pain
• Symptom Severity (SS) score, on which the patient scores specific fibromyalgia symptoms, including cognitive issues, fatigue, headache, and dizziness
The treatment is focused on minimizing the pain and fatigue experienced through the use of medications (e.g., pregabalin, duloxetine, and milnacipran), exercise, biofeedback, and acupuncture.
Muscular Dystrophy
Learning Objective: Discuss muscular dystrophy, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Muscular dystrophy (MD) is a collection of more than 30 inherited diseases that cause muscle weakness and muscle loss. Some of these diseases affect children, whereas others appear in middle-aged adults.
About half of the people with MD have Duchenne muscular dystrophy (DMD), which is the most common form of MD. DMD is usually diagnosed in boys between the ages of 3 and 5. This fast-progressing condition usually causes weakness in the arms and legs, leading to trouble walking. It is usually diagnosed by the age of 3. Boys are affected much more frequently than girls.
Muscular dystrophy may be congenital or caused by a genetic mutation that disrupts the body’s ability to make muscle-protecting proteins. The signs, symptoms, onset, and affected muscle groups depend on the specific disease, though the main sign of MD is progressive muscle weakness. The signs and symptoms of Duchenne muscular dystrophy include frequent falls, trouble running and moving from lying to sitting position, muscle pain and stiffness, and learning disabilities.
After the examination, the provider may order a creatine kinase (CK) blood test. Without trauma, high levels of CK suggest muscle disease, such as MD. Additional diagnostic tests include electromyography, genetic testing, and a muscle biopsy. Treatments can help improve quality of life, help people remain mobile for as long as possible, and reduce or prevent bone and spinal complications. Treatments include corticosteroids, heart medication, range of motion and stretching exercises, braces, and assistive devices (e.g., walkers, wheelchairs). There is no cure for muscular dystrophy.
Myalgic Encephalomyelitis
Learning Objective: Discuss myalgic encephalomyelitis, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Myalgic encephalomyelitis (ME), also called chronic fatigue syndrome (CFS), is a disabling, complex illness. People who have ME are not able to do their normal activities.
ME is most common in people between the ages of 40 and 60, though it can affect anyone. Women are affected by it more often than men. The cause of ME is unknown, but it has been associated with viral infections. Myalgic encephalomyelitis can cause the following conditions:
• Greatly diminished ability to do activities that the person could do prior to the illness.
• Severe fatigue not relieved by sleep or rest.
• Sleep problems, either falling asleep or staying asleep.
• Problems with memory or thinking. Brain fog is common.
• Irregular heartbeat, shortness of breath, and orthostatic intolerance. The person may become dizzy, weak, faint, or lightheaded upon standing or sitting upright.
• Digestive issues and allergies and sensitivities to foods and other products.
• Chills, night sweats, joint pain, and muscle weakness.
The provider may do a complete physical and mental status examination. Blood, urine, and other tests may be ordered to rule out other conditions. Treatment includes the management of symptoms. There is no cure for myalgic encephalomyelitis.
Myasthenia Gravis
Learning Objective: Discuss myasthenia gravis, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Myasthenia gravis affects the voluntary muscles, causing weakness and fatigue with activity, which improves with rest. Myasthenia gravis is most common in men older than 60 and women younger than 40 years of age.
The etiology is an autoimmune neuromuscular disease. The body produces antibodies that block the muscle cells from responding to neurotransmitters from nerve cells. Myasthenia gravis causes muscle weakness, leading to issues with breathing, chewing, swallowing, talking, climbing stairs, lifting objects, and maintaining a steady gaze. Additional symptoms include drooping eyelids, facial paralysis, fatigue, hoarseness, and double vision.
After a detailed neurologic examination, the provider will order imaging tests (CT or MRI), pulmonary function tests, and electromyography (EMG). With myasthenia gravis, the person will have a positive result on an acetylcholine receptor antibody blood test. The treatment is focused on increasing periods of remission. Lifestyle changes are encouraged, including resting, using eye patches, and avoiding stress and heat exposure, which can make symptoms worse. Medications such as neostigmine and pyridostigmine can help with the neuromuscular communication process. Immunosuppressants (e.g., prednisone, azathioprine, cyclosporine, and mycophenolate) may also be used. There is no cure for myasthenia gravis.
Strain
Learning Objective: Describe a strain, including the signs, symptoms, etiology, diagnostic procedures, and treatment
A strain is a tear, partial tear, overuse, or overstretching of a muscle or tendon. A strain can occur suddenly or over time. Hamstring and back muscle strains are common.
Acute strains occur when falling, jumping, or lifting heavy objects. Chronic strains occur with repetitive muscle movements, usually related to one’s job or during a sports activity. Poor condition, fatigue, failing to do warm-up exercises, environmental conditions (e.g., ice), and poor equipment are risk factors for strains. Signs and symptoms of strains include pain, swelling, and difficulty moving the affected muscle. With strains, muscle spasms may be felt.
During the examination, the provider will check the affected area and the range of motion. X-rays and MRI scans may be ordered to rule out other injuries. Treatment includes rest, ice (cold applications), compression (elastic wraps), and elevation (RICE) to help minimize the swelling. Nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics may be taken. With severe strains, a brace or splint may be used to immobilize the area. Surgery may be done to repair a ruptured muscle. With treatment, the prognosis is good.
20.11
Critical Thinking Application
Marissa overhears Dr. Kahn telling a patient to remember RICE for a strain. What does RICE stand for? Why is it used?
Tendinitis
Learning Objective: Describe a strain, including the signs, symptoms, etiology, diagnostic procedures, and treatment
Tendinitis is the inflammation of a tendon. It causes severe swelling of the tendon. Tendinitis occurs after repeated injury to a joint, such as the wrist or ankle. Some of the most common forms are named after the sports that increase their risk:
• Tennis elbow (lateral epicondylitis): Causes pain in the forearm and wrist
• Golfer’s elbow (medial epicondylitis): Causes pain in the inner forearm and numbness or tingling in the fingers
• Pitcher’s shoulder, swimmer’s shoulder, tennis shoulder (rotator cuff tendinitis, impingement syndrome): Causes pain and swelling in the front of the shoulder, a clicking sound when raising the arm, and loss of mobility
• Jumper’s knee (patellar tendinitis): Pain occurs with bending or straightening of the leg
Tendinitis causes pain, tenderness, inflammation in the joint area, and a limited range of motion.
The provider will do an examination. In most cases, x-rays and other imaging procedures are not required unless the problem continues. Treatment consists of rest, splinting, heat and cold therapy, medications (NSAIDs, analgesics, and corticosteroid injections), and physical therapy.
Tetanus
Learning Objective: Describe tetanus, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Tetanus, also called “lockjaw,” is a serious condition that can lead to a medical emergency. Getting the tetanus vaccine can help prevent tetanus.
Tetanus is caused by Clostridium tetani bacteria. The spores from the Clostridium tetani bacteria are found in the soil, dust, manure, and saliva. Often, the spores enter the body through an injury, such as a deep cut, puncture wound, or eye injury. Once the spores enter the body, they develop into bacteria. Tetanus can cause painful muscle stiffness throughout the body, jaw cramping, headaches, seizures, fever, sweating, and vital sign changes (e.g., blood pressure and pulse). A person can have trouble opening her or his mouth and swallowing.
The provider performs an exam. No diagnostic tests exist to confirm tetanus. Treatment includes hospitalization, human tetanus immune globulin (TIG), medications to manage the muscle spasms, tetanus vaccine, and antibiotics. The more severe the case of tetanus, the poorer the prognosis. For those that survive tetanus, recovery may take up to 4 months.
Torticollis
Learning Objective: Describe tetanus, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
Torticollis occurs when the neck muscles spasm. This causes the head to tilt, lean forward or backward, or be rotated.
Torticollis can be genetic. In infants, it can be caused by birth trauma or a spinal abnormality. In adults, it can be caused by poor posture, insufficient head support while sleeping, or neck injury or infection. Torticollis causes neck spasms, tremors, headache, neck pain, and swelling and stiffness of the neck muscles. The range of motion for the head can be limited. One shoulder may be higher than the other shoulder.
After an examination, the provider may order an x-ray or CT scan. Treatment for torticollis present at birth involves passive stretching of the shortened neck muscle. Depending on the cause, treatment may involve heat and cold therapy, physical therapy, Botox injections, and surgery if other treatments fail.
Additional Muscular System Disorders
There are several other muscular system diseases:
• Botulism: A rare but serious disease caused by Clostridium botulinum, which enters the body through contaminated food (e.g., honey, home-preserved/canned foods). The toxins cause muscle paralysis, leading to visual changes, slurred speech, and difficulty swallowing and breathing.
• Congenital myopathies: Rare congenital diseases that cause a lack of muscle tone and muscle weakness, cramps, and contractions, along with delayed motor skills, facial weakness, and drooping eyelids.
• Dermatomyositis (DM): Affects people of all ages and is most common in women. Symptoms start with a rash on the face, chest, or extremities, followed by muscle weakness.
• Endocrine myopathies: Caused by abnormal thyroid gland activity; they lead to weakness, atrophy, stiffness, cramps, and slowed reflexes.
• Ganglion cyst: A benign round or oval lump that develops in the wrist, hand, ankle, or foot. The cyst is filled with a jelly-like fluid and develops along the tendons or joints. These cysts are painless unless they put pressure on a nearby nerve. Then, the person may experience tenderness, weakness, numbness, tingling, or pain in the affected area.
• Muscle atrophy: The loss or wasting of muscle tissue. Physiologic atrophy occurs when muscles are not used enough, muscle tissue is lost. People who are bedridden or have conditions that cause limited movement (e.g., casts, strokes) are at risk for muscle atrophy. Pathologic atrophy is seen with starvation, long-term corticosteroid use, and aging. Neurogenic atrophy is caused by an injury (e.g., spinal cord injury) or disease of a nerve that connects with a muscle (e.g., amyotrophic lateral sclerosis and polio).
• Myositis: Inflammation of the muscles caused by an injury, infection, or an autoimmune disease.
• Myotonia congenita: A congenital condition that causes a delay in muscle relaxation after contraction. Early symptoms include difficulty swallowing, shortness of breath, falls, and difficulty opening the eyes. After the person starts moving, the muscles relax, and the movements become normal.
• Sarcopenia: Causes progressive skeletal muscle loss due to age; this causes a decrease in muscle strength.
• Shin splints: Cause pain in the front of the lower leg due to overuse of the leg muscles, tendons, or tibia. They are the result of inflammation of the bone tissue, tendons, and muscles around the tibia.