In ALS, weakness typically progresses from which to which?

In ALS, weakness typically progresses from which to which?

• A. Distal to proximal
• B. Proximal to distal
• C. Random pattern
• D. No progression

Answer: (A)

Weakness in ALS typically begins in the distal muscles and then progresses to proximal muscles. This pattern reflects how motor neurons controlling the longest, farthest-reaching muscle fibers—such as those in the hands and feet—are affected early. As the disease advances and more motor neurons fail, weakness spreads to muscles closer to the body's core, like the arms and legs, and eventually to bulbar muscles involved in speech and swallowing. The other options don’t fit the usual trajectory: starting with proximal muscles first is less common, a random pattern isn’t how ALS progresses, and no progression contradicts the defining, degenerative nature of the disease.

Weakness in ALS typically begins in the distal muscles and then progresses to proximal muscles. This pattern reflects how motor neurons controlling the longest, farthest-reaching muscle fibers—such as those in the hands and feet—are affected early. As the disease advances and more motor neurons fail, weakness spreads to muscles closer to the body's core, like the arms and legs, and eventually to bulbar muscles involved in speech and swallowing. The other options don’t fit the usual trajectory: starting with proximal muscles first is less common, a random pattern isn’t how ALS progresses, and no progression contradicts the defining, degenerative nature of the disease.