Duchenne Muscular Dystrophy Quiz

A condition where muscles shorten and become stiff, often due to weakness and imbalance. It can occur in the ankles, hips, and other areas.

A sideways curvature of the spine, common in DMD, affecting over 80% of boys. It progresses faster after the loss of walking ability, and requires surgery when the curve reaches 40 degrees.

A weakened heart muscle, affecting more than 60% of boys with DMD. It can lead to heart conduction problems and enlargement of the heart.

Weakening of the muscles involved in breathing, typically becoming noticeable around age 10-12. This can lead to difficulties breathing, especially at night.

Challenges with the digestive system, often due to weakened muscles in the stomach and intestines. This can cause constipation and difficulty absorbing food.

A blood test that measures the levels of creatine kinase, an enzyme found in muscles. It's often elevated in DMD, even before symptoms appear.

A test that uses sound waves to visualize muscles, helping to assess muscle damage and its extent.

A test that examines electrical activity in muscles, providing evidence of muscle damage and dysfunction.

A clinical sign observed in Duchenne muscular dystrophy (DMD), where an individual uses their hands to push themselves up from the floor, resembling 'walking hands up the legs.'

A characteristic gait pattern in DMD, characterized by an excessive forward curve of the lower spine (lumbar lordosis), a wide base of support, and a tendency to walk with the center of gravity (LOG) shifted behind the hips.

A prominent abdomen in DMD, due to the weakness of abdominal muscles, causing the belly to stick out.

A broad base of support when walking, seen in DMD, due to weakness in the hip abductor muscles.

A condition in which the hip drops on the side opposite to the stance leg upon lifting the other leg, indicating hip abductor muscle weakness, as seen in DMD.

A weakened quadriceps muscle (front of thigh) causes the knee to extend excessively, potentially leading to instability.

A characteristic of DMD due to contracted calf muscles and weak dorsiflexor muscles, causing the individual to walk on their toes.

The progressive weakening of muscles in Duchenne muscular dystrophy (DMD), primarily affecting proximal muscles (closer to the body) earlier and more severely.

A group of genetic disorders characterized by progressive muscle weakness and degeneration, with typically symmetric muscle wasting, leading to increasing deformity and disability.

The most common and severest form among the dystrophic disorders, presenting in early childhood with rapid progression of weakness and disability.

DMD primarily affects male offspring, inherited from their mothers who are carriers of the faulty gene.

A protein crucial for maintaining the stability of the muscle cell membrane, linking the membrane to the contractile muscle protein (actin).

Lack or absence of dystrophin disrupts the muscle cell membrane's stability, leading to calcium influx, activation of a proteinase, cell destruction, and eventual replacement by fatty and connective tissue.

Early signs include delayed motor development, difficulty walking, and a tendency to fall.

The child exhibits difficulty getting off the floor, climbing stairs, running, and often falls, with increased lumbar lordosis and a waddling gait.

Muscle weakness becomes noticeable around 3-5 years old, affecting both sides of the body, primarily the proximal muscles (those closer to the core) compared to the distal muscles (those further away).

Although the muscles may appear larger, the hypertrophy is false as the muscle tissue has been replaced by fat and fibrous tissue.

Deep tendon reflexes are reduced due to muscle wasting, sensation remains normal and the problem primarily affects muscles.

CK levels are measured in newborn dried blood spots for initial DMD screening. Levels significantly above 3 standard deviations (3SD) indicate a potential for DMD and trigger further testing.

Corticosteroids are the standard treatment for DMD, slowing muscle strength decline and improving function. They are used to prolong walking, respiratory function and spinal alignment. Evidence suggests steroids may also help with cardiac function.

Possible side effects of corticosteroid therapy for DMD include weight gain, acne, growth retardation, delayed puberty, and behavioral changes.

Deflazacort and vamorolone are two corticosteroids that may have fewer side effects compared to others used in DMD treatment.

Exon-skipping therapy involves drugs that skip mutated sections in the DMD gene, resulting in a shorter but functional dystrophin protein.

Eteplirsen (Exondys 51), Golodirsen (Vyondys 53), and Viltolarsen (Viltepso) are FDA-approved exon-skipping therapies for DMD patients with specific gene mutations.

Gene therapy is a promising new approach for DMD. Elevidys (delandistrogene moxeparvovec-roki) is the first FDA-approved gene therapy for ambulatory DMD patients aged 4-5 with specific DMD gene mutations.

Elevidys (delandistrogene moxeparvovec-roki) is a gene therapy approved for ambulatory DMD patients aged 4-5 with a specific confirmed mutation in the DMD gene, offering a newer treatment option.

A one-time IV infusion gene therapy that delivers a modified, functional version of dystrophin; aims to delay or halt DMD progression.

A non-steroidal drug approved for DMD patients aged six and older; reduces inflammation and muscle loss.

A protein normally produced during early muscle development that can compensate for dystrophin deficiency.

Drugs that increase utrophin levels in mature muscles, potentially helping to compensate for lack of dystrophin.

Drugs that aim to reduce muscle inflammation and fibrosis, potentially promoting muscle regeneration.

Drugs that inhibit myostatin, a protein that limits muscle growth, allowing muscles to grow larger and stronger.

Drugs that increase blood flow to muscles, potentially improving muscle function.

Therapy using cells from a donor to restore dystrophin in muscles, showing promise in animal studies.

Cells reprogrammed to become pluripotent (capable of becoming any cell type), potentially used in DMD therapy.

This type of treatment aims to maintain function as long as possible, preventing complications and promoting quality of life.

Muscular dystrophy characterized by difficulty climbing stairs and a tendency to fall. It primarily affects proximal muscles, leading to weakness in the neck, trunk, pelvis, and shoulder girdle. Muscle cramps commonly occur in late childhood/early adolescence.

Typically affects proximal muscles, but can spread to distal muscles with time. It includes winging of the scapula, lumbar lordosis, abdominal protrusion, a waddling gait, poor balance, and difficulty raising arms overhead. Onset can be in late childhood, adolescence, or early adulthood.

A milder form of muscular dystrophy, characterized by facial muscle weakness (expressionless face, inability to close eyes, pouting lip, pucker mouth or whistle, and sagging of the jaw), shoulder girdle weakness (winging, forward shoulders, difficulty raising arms), and delayed weakness in the lower extremities.

An autosomal dominant inheritance pattern. The onset is typically early adolescence, but can occur at any age.

A variation of FSHD involving the proximal muscles of the shoulder girdle, sparing the facial muscles. Weakness slowly spreads to the distal lower extremities over several years, causing symptoms like shoulder weakness, winging of the scapula, and foot drop.

A group of inherited disorders characterized by a rapid progressive loss of muscle strength, progressive respiratory impairment, and mixed central and peripheral symptoms, including brain, muscle, and visual system involvement. The onset occurs at birth or shortly after.

A type of muscular dystrophy characterized by delayed relaxation of skeletal muscles, increased excitability, and the presence of myotonia. The most common type involves weakness and atrophy of facial muscles, mild weakness of limb muscles, cataracts, baldness, cardiac conduction defects, respiratory insufficiency, and endocrine dysfunction.

A type of Myotonic Dystrophy that is the most severe, characterized by weaknesses and myotonia from birth.

Marked by slowly progressive, symmetric atrophy and weakness of the muscles of the shoulder and upper arms and lower legs. There is also usually mild facial weakness. Contractures of the spine, ankles, knees, elbows, and back of the neck occur early.

Most common form of MD. Characterized by difficulty climbing stairs and a tendency to fall due to weakness. It affects the proximal muscles in a more prominent manner than the distal muscles. Muscle cramps are common.

The most common form of MD. Characterized by difficulty with walking due to weakness of proximal muscles, including the hip, pelvic muscles, and thighs. It also affects the shoulder and upper arms. This form is always fatal, and death typically occurs from respiratory failure.

A group of genetic diseases that cause progressive weakness and degeneration of skeletal muscles. Many variants of the disease are known, but the most common involve the muscles in the hips (proximal muscle groups).

BMD can progress until adulthood, with patients often surviving into their 40s. Death is often caused by respiratory dysfunction or heart failure.

This type of MD has a variable progression, but is usually slow, with relatively normal lifespan.

FSHD has a wide range of severity, but usually progresses slowly and doesn't significantly impact one's lifespan. While ambulation is lost later in life, life expectancy is often similar to those without the disease.

This type of MD has a variable course, even within the same family, but is typically slow. While the progression may be variable, most patients have a relatively normal lifespan.

CMD is progressive in nature, with some individuals experiencing death in the first years of life, while others experience a slower, but still progressive decline in health.

This type of MD has a rate of progression that depends on the age of onset. Overall, the disease is relatively mild with greater functional independence and longevity, with patients often living into their 5th or 6th decade.