Which condition is characterized by increasing dysphagia to liquids compared to solids?

The correct answer is motor neurone disease (MND), which is associated with the progressive degeneration of motor neurons in the brain and spinal cord. In this condition, patients often experience dysphagia, meaning they have difficulty swallowing. The characteristic of having more pronounced difficulty swallowing liquids compared to solids can be attributed to the nature of the neuromuscular involvement in MND. As the disease progresses, the muscle coordination required for swallowing is affected, making it harder to manage thin liquids that require a complex and coordinated swallowing mechanism. Solids may remain easier at times because they can be chewed and moistened more easily, but once the liquid is introduced, the patient's ability to coordinate the swallowing process becomes compromised.

In other conditions, such as multiple sclerosis, myasthenia gravis, or spinobulbar muscular atrophy, dysphagia may also occur, but typically the pattern of dysphagia is not specifically characterized by a more significant problem with liquids over solids. Therefore, the distinct symptom pattern of increasing dysphagia to liquids in MND makes it the correct answer in this context.