"Storming" is the brain's rebalancing attempt of the
Sympathetic and Parasympathetic Nervous System, which, after a severe TBI, can occur any time from 24 hrs. to weeks after a severe TBI, and last for a long period of time in that phase of 'recovery'.
This
Critical Care Nursing Handout Family sheet is informative/helpful. (click on yellowed text for larger readable text)