Difficulty swallowing and Sudden weakness in entire body in elderly

Patient: My grandfather has always been jogging everyday and consumes a healthy diet. However recently(2 weeks ago), his mobility and health deteriorated steeply without known reasons.He complains about a sudden difficulty in swallowing and weakness and pain in his limbs. He had gone for X-Ray and blood tests and undergo lots if medication but none seems to be effective and all the results gives no clear indication of what is the cause. Looking at the symptoms, I suspect that it is oropharyngeal dysphagia or neurological degeneration.Currently, he is too weak to move and he is reduced to sleeping most of the time. His diet consists of small portions of mashed food.Can you please help me assess the situation and how I could1) Better cater for his diet to ensure that he has sufficient nutrition2) Help him recover faster so that he could walk around again.3) Understand why a healthy and physically fit man like him can suffer a sudden deterioration in health and mobility without any reason.Thank you very much.With gratitude,Ting

Doctor: