A 52-year-old woman presents with upper limb weakness and dysphagia. What is the most likely diagnosis?

In considering the symptoms presented—upper limb weakness and dysphagia—the most likely diagnosis is motor neurone disease (MND). This condition is characterized by the degeneration of motor neurons in the brain and spinal cord, leading to progressive muscle weakness and atrophy.

The upper limb weakness indicates that the motor neurons innervating the arms are affected, while dysphagia suggests involvement of the bulbar motor neurons that control swallowing functioning. Both symptoms aligning with MND underscore the impact that the disease has on voluntary muscle control, which progressively worsens over time.

While other conditions like multiple sclerosis, myasthenia gravis, and spinobulbar muscular atrophy can present with similar symptoms, they have distinct characteristics and progressions. Multiple sclerosis typically presents with relapsing episodes and sensory disturbances in addition to motor symptoms, while myasthenia gravis is characterized by muscle weakness that worsens with activity and improves with rest. Spinobulbar muscular atrophy often presents with more significant involvement of bulbar symptoms, and although it can lead to dysphagia, the pattern of upper limb weakness is more indicative of MND in this scenario.

Thus, the combination of upper limb weakness and dysphagia is most consistent with motor