Question

What is the condition characterized by symmetrical weakness and wasting of pelvic, shoulder, and proximal limb muscles?

1) Duchenne muscular dystrophy
2) Polymyositis
3) Amyotrophic lateral sclerosis (ALS)
4) Motor neuron disease

Answer 1

2) Polymyositis

Polymyositis is the condition characterized by symmetrical weakness and wasting of pelvic, shoulder, and proximal limb muscles, which is due to muscle inflammation. It differs from Duchenne muscular dystrophy and ALS, which have distinct causes and progression.

Step-by-step explanation:

The condition characterized by symmetrical weakness and wasting of pelvic, shoulder, and proximal limb muscles is known as polymyositis. This condition is part of a group of diseases called inflammatory myopathies, where the muscles are affected by inflammation, leading to muscle weakness and wasting. It is not to be confused with Duchenne muscular dystrophy (DMD), which is a genetic disorder characterized by progressive skeletal muscle weakness due to a lack of the protein dystrophin that leads to muscle cell damage over time. Unlike polymyositis, DMD begins in early childhood and primarily affects boys, progressing more rapidly. Amyotrophic lateral sclerosis (ALS) and motor neuron disease (another term often used for ALS) both involve the degeneration of motor neurons and also lead to muscle atrophy, but are distinct from polymyositis in their underlying causes and progression.