Which condition is suggested by a 55-year-old male with progressive weakness and muscle atrophy without sensory changes?

The condition suggested by a 55-year-old male with progressive weakness and muscle atrophy without sensory changes is amyotrophic lateral sclerosis (ALS). ALS is a neurodegenerative disorder that specifically affects motor neurons in the brain and spinal cord. This leads to the characteristic symptoms of muscle weakness and atrophy due to the improper functioning and eventual death of motor neurons, which control voluntary muscle movements.

In ALS, patients often experience muscle weakness that progresses over time, as well as muscle wasting due to denervation. Sensory pathways remain intact, which is why there are no sensory changes noted in this case. Unlike some other neuromuscular disorders, such as myasthenia gravis where muscle weakness fluctuates and typically involves ocular symptoms, ALS presents with a more relentless and progressive decline in motor function without accompanying sensory deficits.

Polymyalgia rheumatica primarily causes muscle pain and stiffness, particularly in the shoulders and hips, rather than true muscle atrophy. Multiple sclerosis is characterized by a variety of symptoms, including sensory disturbances, and the motor symptoms can present differently, often with more variability and additional neurological signs. Therefore, in this scenario, the clinical picture aligns best with amyotrophic lateral sclerosis.