Final answer:
Post-polio syndrome is the term for symptoms of exhaustion and muscle and joint pain that occur decades after having had a disease that is an inflammation of the gray matter of the spinal cord.
Step-by-step explanation:
The term for symptoms of exhaustion and muscle and joint pain that occur decades after having had a disease that is an inflammation of the gray matter of the spinal cord is Post-polio syndrome. Post-polio syndrome is a condition that affects people who have had polio in the past, typically in their childhood. It is characterized by symptoms such as muscle weakness, fatigue, and joint pain.