CME INDIA Case Presentation by Dr Ashutosh Chandan Dubey (Dr Strange), DNB, Medicine, Renukut (UP).

CME INDIA Case Study:

A 22 yr. old male has come with complaints of palpitation for past 2 days at night. No associated chest pain or SOB.
No sensory, cerebellar, autonomic dysfunction, normal cranial Nv, spine and cranium and mental status.

Patient was examined thoroughly for type of weakness.
Pt has pseudohypertrophy of calf muscles, proximal myopathy with power of 4/5 in flexors of thigh and extensors of thigh. Also, weakness of shoulder girdle and biceps and triceps.
Patient has problem in standing from sitting position and while getting off from bed. Also putting objects on shelf.
Patient is doing yoga and aerobic exercise which have helped him in performing his daily routine activities. But after doing work he easily gets fatigued.
Patient has developed cardiomyopathy and arrhythmia. Patient is non hypertensive, no DM no thyroid disorder.
Family history of similar disorder was absent.

Final Diagnosis:

Becker’s Muscular Dystrophy and LV dysfunction with EF of 40%. (DCMP)

CME INDIA Learning Points:

Becker muscular dystrophy is a progressive weakness and wasting of the skeletal and cardiac (heart) muscles. It primarily affects males.
Muscle weakness usually becomes apparent between the ages of 5 and 15.
Many cases present with shortness of breath due to cardiomyopathy and this could be is the first sign. Signs and symptoms of dilated cardiomyopathy can include an irregular heartbeat (arrhythmia), shortness of breath, extreme tiredness (fatigue), and swelling of the legs and feet. These heart problems worsen rapidly and become life-threatening in most cases.
BMD is caused by a mutation in the DMD gene and is inherited in an X-linked recessive manner.

How to differentiate with Duchenne muscular dystrophy?

Duchenne and Becker muscular dystrophies have similar signs and symptoms.
They are caused by different mutations in the same gene.
The two conditions differ in their severity, age of onset, and rate of progression.
In boys with Duchenne muscular dystrophy, muscle weakness tends to appear in early childhood and worsen rapidly. Affected children may have delayed motor skills, such as sitting, standing, and walking. They are usually wheelchair-dependent by adolescence.
The signs and symptoms of Becker muscular dystrophy are usually milder and more varied. In most cases, muscle weakness becomes apparent later in childhood or in adolescence and worsens at a much slower rate.
Both the Duchenne and Becker forms of muscular dystrophy are associated with a heart condition called cardiomyopathy.

What to get in clinical examination?

Abnormally developed bones, leading to deformities of the chest and back (scoliosis).
Abnormality of heart muscle function (cardiomyopathy).
Congestive heart failure or irregular heartbeat (arrhythmias).
Muscle deformities:
- Contractures of heels and legs.
- Fat and connective tissue (pseudohypertrophy) in calf muscles.
Muscle wasting that begins in the legs and pelvis, then progresses to the muscles of the shoulders, neck, arms, and respiratory system.

What investigations to advice?

CPK.
Electromyography (EMG).
Genetic Testing: Mutations that lead to an abnormal version of dystrophin that retains some function usually cause Becker muscular dystrophy, while mutations that prevent the production of any functional dystrophin tend to cause Duchenne muscular dystrophy.
Muscle Biopsy in doubtful cases.
Prognosis/Treatment.
Males with Duchenne muscular dystrophy typically live into their twenties, while males with Becker muscular dystrophy can survive into their forties or beyond.
Current treatment aims to relieve symptoms and improve quality of life.

Kushal Godkhindi MD (Bom) on October 21, 2020 at 9:15 pm
Duchenne children don’t walk properly at all as the disease starts early before they learn normal walk: where as Becker’s children walk normally later develop waddling gait
That’s the main differenciating point