Thank you for writing.
Storming is indeed very traumatic to see. A patient can jerk, stiffen, breath rapidly and have similar other symptoms that are pretty awful.
They do go away eventually (the medications do help) but can last several weeks or months.
Rainbow Rehab have a great page on these storms - cut and paste here (you may have come across this already):
Also, please join on anoxic thread which is quite active. Here, families tell their stories, ask questions and get information. Storming is also spoken about:
We wish you and your son the best.