Written from hospital bed to hospital bed as I learned how to read and write again, speak and process brain information. Traumatic brain injury (TBI) is sometimes followed by a more rare condition, diabetes insipidus (DI) that has nothing to do with blood sugar.
DI occurs because the posterior pituitary gland, that hangs from the brain like a dangling apple, gets smashed on its back, onto the skull. A hormone (i.e. DDAVP, or vasopressin, or anti-diuretic hormone) gets "knocked out," so a 'higher' hormone completely loses communication with it.
What happens next is that this 'higher' hormone, located in the hypothalamus of the brain, speaks and speaks and speaks and speaks and speaks to the pituitary gland (not knowing it is "broken" or "severed")...and the body pees itself to death. Because the pituitary gland is missing "anti-diuretic" hormone, there is nothing any more to tell the hypothalamus "We're in the desert. Stop Peeing!"
So most people with TBI die of DI via dehydration and kidney failure, perhaps mostly in their sleep. They are thirsty, thirsty, thirsty, yet keep peeing, peeing, peeing. They don't know that they can NEVER catch up in the drinking. I have had it twice now, and it is no fun. Titrating salt and water, water weight and Na levels ~ That's because the DDAVP is gone. Treatment? DDAVP or vasopressin, or Anti-diuretic hormone. No one wants to be on this drug regimen to "fake" an illness, as I was accused of doing. The unneeded drug will kill a person. Anyway, that's your pathophysiology lesson for today.
Pituitary gland. Posterior pituitary is in blue. Pars nervosa and infundibular stalk are not labeled, but pars nervosa is at bottom and infundibular stalk is at top.)