Muscle Disorders and Myopathies Quiz

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Questions and Answers

What is myopathy primarily characterized by?

Weakening and atrophy of skeletal muscles (correct)

Rapid muscle growth and development

Inflammation of the nerve cells

Increased muscle strength and coordination

Which type of myopathy is primarily inherited and affects muscle tissue?

Mitochondrial myopathies

Acquired myopathies

Hereditary myopathies (correct)

Metabolic myopathies

What characterizes muscular dystrophies?

They are exclusively found in adults

They always show normal creatine phosphokinase levels

They result in muscle wasting and weakness with elevated CPK levels (correct)

They are caused by environmental factors

Which myopathy does NOT present necrotic or degenerative changes?

Congenital myopathies Signup and view all the answers

What is the primary defect in metabolic myopathies?

Disruption in cellular energy metabolism Signup and view all the answers

Which of the following is a hallmark sign of mitochondrial myopathies?

Multi-system dysfunction Signup and view all the answers

Which of the following represents an established condition within congenital myopathies?

Nemaline myopathy Signup and view all the answers

What is responsible for the diverse group of metabolic myopathies?

Defects in cellular energy metabolism Signup and view all the answers

What type of muscle examination is performed due to easy fatigability in myopathic patients?

Group muscle test Signup and view all the answers

Which assessment is NOT a part of the routine motor examination?

Electromyography Signup and view all the answers

What type of assessment is used to determine a patient’s functional abilities and disabilities?

Functional assessment Signup and view all the answers

Which of the following is a primary goal of physical therapy in patients with muscular dystrophy?

Preventing contractures Signup and view all the answers

At which stage is active assisted exercise introduced in the Rehnold’s program for muscular dystrophy treatment?

Ambulant stage Signup and view all the answers

What is the purpose of implementing breathing exercises in the first stage of muscular dystrophy treatment?

To maintain respiratory function Signup and view all the answers

What should be avoided according to physical therapy protocols?

Resistive exercises Signup and view all the answers

During which stage of the Rehnold's program is underwater exercise utilized?

Bound to wheelchair stage Signup and view all the answers

What is a notable physical manifestation of muscle weakness due to advancing age?

Waddling gait Signup and view all the answers

Which muscles are typically spared from atrophy in individuals with advancing age-related muscle weakness?

Sternocleidomastoid and clavicular head of pectoralis Signup and view all the answers

What is the significance of a positive family history in the context of muscle degeneration?

It suggests a genetic predisposition Signup and view all the answers

Which test helps confirm the diagnosis of muscle degeneration by analyzing muscle activity?

Electromyogram (EMG) Signup and view all the answers

Elevated levels of which enzyme could indicate muscle injuries or diseases such as muscular dystrophy?

Creatine kinase (CPK) Signup and view all the answers

What does the Gowers' sign indicate in individuals experiencing muscle weakness?

Difficulty rising from the floor Signup and view all the answers

Which of the following describes the role of the creatine kinase (CPK) test?

Evaluates muscle enzyme levels Signup and view all the answers

What condition could be associated with elevated CK-MB enzymes in the blood?

Inflammation of the heart muscle Signup and view all the answers

What is a complication associated with late-stage muscular dystrophy?

Paralysis of respiratory muscle Signup and view all the answers

Which of the following describes myasthenia gravis?

It causes weakness in skeletal muscles. Signup and view all the answers

What is the main cause of worse prognosis in patients with muscular dystrophy?

Respiratory muscle paralysis Signup and view all the answers

What role do antibodies play in myasthenia gravis?

They block or destroy receptor sites for acetylcholine. Signup and view all the answers

What type of splint is typically used at night for patients with muscular conditions?

Night splints Signup and view all the answers

Which demographic is most commonly affected by myasthenia gravis?

Women younger than 40 Signup and view all the answers

What aspect of therapy aims to enhance daily living activities for patients?

Adaptation of house for ADL Signup and view all the answers

What is a primary symptom of myasthenia gravis?

Weakness and rapid fatigue of voluntary muscles Signup and view all the answers

What is the role of muscle-specific receptor tyrosine kinase in the body?

It helps in the formation of the nerve-motor junction. Signup and view all the answers

Which of the following is NOT a symptom of myasthenia gravis?

Hyperactivity and restlessness. Signup and view all the answers

Which test is utilized for the assessment of myasthenia gravis?

Repetitive nerve stimulation test. Signup and view all the answers

What is a potential life-threatening complication of myasthenia gravis?

Myasthenic crisis. Signup and view all the answers

Which treatment is commonly used to help relieve symptoms of myasthenia gravis?

Corticosteroids. Signup and view all the answers

What lifestyle change can help alleviate symptoms of myasthenia gravis?

Getting plenty of rest. Signup and view all the answers

Which of the following treatments involves the removal of harmful antibodies from the blood?

Plasmapheresis. Signup and view all the answers

What factor heavily influences the long-term outlook for individuals with myasthenia gravis?

Severity of symptoms and response to treatment. Signup and view all the answers

What is the main cause of muscle fiber loss in Duchenne Muscular Dystrophy?

Lack of dystrophin Signup and view all the answers

What differentiates Becker Muscular Dystrophy from Duchenne Muscular Dystrophy?

BMD typically does not have associated ECG changes Signup and view all the answers

Which age group typically first experiences symptoms of Becker Muscular Dystrophy?

Second decade Signup and view all the answers

What is the nature of the muscle weakness in facio-scapulo-humeral muscular dystrophy?

Asymmetrical and slow progression Signup and view all the answers

What skeletal deformity is commonly associated with Duchenne Muscular Dystrophy?

Scoliosis Signup and view all the answers

Which of the following is a common characteristic of Duchenne Muscular Dystrophy but not Becker Muscular Dystrophy?

Progressive muscle weakness in childhood Signup and view all the answers

What is often observed in the ECG of patients with Duchenne Muscular Dystrophy?

Frequent arrhythmias Signup and view all the answers

What type of genetic inheritance is associated with Duchenne Muscular Dystrophy?

X-linked recessive Signup and view all the answers

Study Notes

Myopathy: Definition and General Classifications

Myopathy is a general term for muscle disease not related to nerve or neuromuscular junction disorders.
It encompasses a wide range of etiologies.
Myopathy typically leads to muscle weakness and atrophy, particularly affecting proximal muscles like those in the thighs and shoulders.

Hereditary Myopathies (Primary)

Hereditary myopathies are inherited conditions primarily impacting skeletal muscle tissue.
These disorders result from mutations in genes encoding proteins crucial for muscle structure and function.

Muscular Dystrophies (Primary)

Muscular dystrophies are a heterogeneous group of inherited diseases affecting both children and adults.
At least 30 different genes contribute to the development of these illnesses.
Duchenne and Becker muscular dystrophies are common forms.
These diseases result from genetic defects on the X chromosome.
They are characterized by muscle wasting (atrophy), weakness, and elevated creatine phosphokinase (CPK) levels.

Congenital Myopathies (Present at Birth)

Congenital myopathies are characterized by the absence of necrotic or degenerative changes within muscles.
Contrasting muscular dystrophies, CPK levels in these conditions are often normal.
Well-established conditions within this group include nemaline myopathy, central core disease, X-linked myotubular myopathy, and centronuclear myopathy.

Metabolic Myopathies

Metabolic myopathies comprise a diverse range of disorders stemming from defects in cellular energy metabolism.
These defects affect the breakdown of fatty acids and carbohydrates, hindering the generation of adenosine triphosphate (ATP).

Mitochondrial Myopathies

Mitochondrial myopathies are a large group of disorders arising from primary dysfunction in the mitochondrial respiratory chain.
This dysfunction often leads to muscle disease, and these conditions frequently involve multi-system dysfunction, along with genetic etiologies.

Genetic Defects

Genetic defects affecting calcium, sodium, potassium, and chloride channels within skeletal muscles can lead to periodic paralyses and nondystrophic myotonias.
Myotonia congenita, paramyotonia congenita, hyperkalemic periodic paralysis, and hypokalemic periodic paralysis, and potassium-aggravated myotonia are conditions resulting from such defects.

Acquired/Secondary Myopathies

These types of myopathies develop later in life, as opposed to hereditary conditions.

Idiopathic Inflammatory Myopathies

Polymyositis (PM) and dermatomyositis (DM) are examples of idiopathic inflammatory myopathies, characterized by muscle aches, tenderness, and weakness, often fluctuating over time.
Patients may experience fever and appetite loss.
DM is distinguished by a distinctive skin rash, typically a purple discoloration around the eyes and cheeks.

Endocrinologic Myopathies

Steroid myopathy is the most common endocrine muscle disease, and is often linked to steroid excess.
Cushing's syndrome (due to hormonal overproduction by the pituitary and adrenal glands) results in myopathy. Myopathies can also arise from excess parathyroid hormone resulting in hypercalcemia, a contributing factor to proximal muscle pain and weakness.
Conditions such as hyperthyroidism, where thyroid glands produce excessive thyroxine, or hypothyroidism, from insufficient thyroxine production, can also cause myopathies, with muscle weakness being a symptom in both situations.

Toxic Myopathies

Toxic myopathies result from exposure to certain medications/chemicals, including lipid-lowering agents, anesthetics, narcotics (e.g., cocaine, heroin, meperidine), corticosteroids, and excessive alcohol intake.
These substances can harm skeletal muscle.

Diagnostic Investigations

Diagnostic investigations for myopathies often involve a combination of:
- Positive family history and genetic testing
- Urine analysis
- Elevated serum enzymes (like creatine kinase)
- Nerve conduction studies
- Electromyography (EMG)
- Muscle biopsy
- Protein analysis
- DNA analysis

Clinical Classifications (of progressive muscular dystrophies)

Shoulder girdle type, scapulo-humeral type, facio-scapulo-humeral type, pelvic girdle type, pseudo-hypertrophy type (duchenne, backer), LGMD Atrophic type, distal type of gower, ocular type, and oculo-pharyngeal type, and myotonic dystrophy are examples of clinically identified progressive types

Myasthenia Gravis

Myasthenia gravis is a neuromuscular disorder characterized by muscle weakness, particularly affecting those controlled voluntarily.
This weakness is accompanied by rapid muscle fatigue.
It results from a breakdown in the normal communication between nerves and muscles.
The disease is more common in women under 40 and men over 60.
Symptoms generally worsen over time.

Myasthenia Gravis: Pathogenesis

The immune system produces antibodies that block or destroy acetylcholine receptor sites on muscles.
This blockage reduces stimulation of muscles, leading to weakness.
Antibodies may also affect receptor tyrosine kinase function, which further contributes to impaired neuromuscular signaling, leading to weakness and fatigue of affected muscles.

Myasthenia Gravis: Symptoms

Initial signs often include weakness of eye muscles.
Conditions such as ptosis (drooping eyelids), diplopia (double vision), facial weakness, swallowing difficulties, and respiratory distress are possible symptoms.

Myasthenia Gravis: Assessment

Assessing myasthenia gravis typically involves checking reflexes, evaluating muscle tone, testing eye movements while looking for muscle tone involvement, and applying repetitive nerve stimulation testing while checking for antibodies linked to MG. A CT scan or MRI of the chest is used to rule out tumors in affected regions.

Myasthenia Gravis: Treatment

Medications, including immunosuppressants and corticosteroids, can help relieve symptoms and slow the progression of myasthenia gravis.
Thymus gland removal might be helpful for certain patients with myasthenia gravis.
Techniques like plasmapheresis (plasma exchange) and intravenous immunoglobulin (IVIG) therapy can also be used to manage symptoms.

Myasthenia Gravis: Complications

Myasthenic crisis, a life-threatening complication involving severe muscle weakness, and respiratory distress.
Individuals with myasthenia gravis have a higher likelihood of developing other autoimmune disorders, such as lupus or rheumatoid arthritis.

Myasthenia Gravis: Long-Term Outlook

Long-term outcomes vary with myasthenia gravis; Some experience mild symptoms, while others require wheelchair assistance.
Prompt diagnosis and appropriate treatment can usually help prevent disease progression.

Physical Therapy Examination

Respiratory and motor assessments, including observations, palpation, individual or group muscle testing, muscle tone assessment, deep tendon reflex examination, range-of-motion examination and sensory assessments, are crucial for diagnosing myopathies and muscular dystrophies.

Physical Therapy Treatment for Myopathies

Treatment involves a variety of approaches tailored to different stages of the diseases, including:
- Muscle shortening exercises
- Exercise programs
- Heat applications
- Technical applications (e.g., night splints)
- Assistance with activities of daily living (ADL)
- Parent instruction/education.
- Equipment adjustments and adaptations

Treatment Prevention

Prevention strategies focus on maintaining independent walking, ambulation, and preventing the need for wheelchair use based on the disease presentation.

Rehnold's Program for Muscular Dystrophies

This program offers treatment strategies in various stages (walking, ambulant, and wheelchair dependent).
Treatment methods include active exercises, passive range-of-motion, and breathing exercises, adapted to each stage.

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Description

Test your knowledge on myopathies and muscular disorders through this comprehensive quiz. Explore the characteristics, types, and assessments related to various myopathies including muscular dystrophies and metabolic myopathies. Ideal for students and professionals in the medical field.