A Colorado man developed a rare spine and brain condition after a monkeypox infection, according to a Sept. 13 report from the CDC.
He developed weakness and numbness in his legs and left arm about nine days after he noticed flu-like symptoms, the report said. An MRI revealed spots on the man's brain and spinal cord, indicating something attacked the protective covering on his nerves.
It is not clear if the virus directly affected his nervous system or if an immune overreaction was responsible.
Monkeypox rarely causes serious neurologic complications. The Colorado man's weakness improved, but he needed assistance walking a month later, the report said.