More medical questions?

Question

A young man has just received serious burns, resulting from standing with his back too close to a bonfire. He is muttering that he never felt the pain. Otherwise, he would have smothered the flames by rolling on the ground. What part of his CNS might be malfunctional?

Answer 1

I know when burns are extensive, the nerve endings stop firing pain signals to the brain. Though he should have been able to feel the heat elsewhere on his body. Is it possible he was intoxicated? It's more common than not that people are unaware they're on fire unless within their sight. I would be more concerned if he didn't feel any pain after realizing he was on fire or during the healing process.

Answer 2

Pain and temperature sensation. A syrinx of the spinal cord typically gets the crossing pain/temp fibers and spares other sensation. The sensory loss is localized to the segments of spinal cord involved, so sensation in the hands and feet might well be normal. It is very difficult to get bilateral sensory loss to pain from a central lesion without a lot of other symptoms. There are people with congenital insensitivity to pain, but these are usually discovered early in life.  My concern would be the possibility of a low cervical-thoracic syringomyelia.  Of course, he could have just been so stoned he did not notice.