What are the side-effects of a pneumoencephalography?

Pneumoencephalography was associated with a wide range of side-effects , including headaches and severe vomiting, often lasting well past the procedure

Headaches and vomiting which are common side effects

Headaches and Vomiting; are the most comun side-effects, of these investigation.

Headaches & severe vomiting were common side effects.

headache and sever vomitting

I think itis using gas or air within CSF