What are typical features of amyotrophic lateral sclerosis and prognosis?

• A. Sensory loss is prominent; rapid recovery
• B. Cognitive decline common early; long survival
• C. Progressive muscle weakness with preserved sensation; respiratory failure is common; no cognitive involvement early
• D. Purely autonomic dysfunction with normal motor strength

Answer: (C)

ALS is a motor neuron disease where both upper and lower motor neurons progressively degenerate. This produces gradual, ongoing weakness and muscle wasting, with reflex changes and spasticity, while sensation is largely spared. As the disease advances, weakness of the respiratory muscles leads to respiratory failure, which is a common cause of death. Cognitive function is usually preserved early, though some patients may develop behavioral or cognitive changes later on; these are not typical at the outset. Autonomic dysfunction and prominent sensory loss are not features of classic ALS. So the description of progressive muscle weakness with preserved sensation, frequent respiratory failure, and no early cognitive involvement best fits the typical ALS pattern and prognosis.