My heart breaks for you. My dad suffered a World War II brain injury. He recovered and learned to walk and talk again. In his 70s, he started having fluid build-up behind the scar tissue in his brain, so they put in a shunt to drain the fluid. This is usually successful. In his case, it backfired and he went into instant dementia, which lasted until his death, then years later.
There has been research showing that repeated concussions in even younger people can lead to Alzheimer's like diseases as they age. There was quite a bit of publicity awhile back (I wrote about it on this site) when a group of NFL wives were creating awareness of the strong link to their husband's head injuries from football and the high level of Alzheimer's these men suffer.
Your grandmother was at a rather advanced age when she was injured. Like my dad, she maybe had earlier stages going on already (there's no way to tell, as of now, when the very earliest stages begin), but the trauma of the injury may have sped up the disease. Perhaps something else is going on, however. Has she had PET scans and other workups by experts who know the nuances of Alzheimer's? We are hearing of non-specialists deciding, based on superficial testing, that people have Alzheimer's. the diagnosis can become a catch-all.
If your grandmother has had all the testing possible, by specialists in Alzheimer's, then it's possible the trauma hastened what was already happening in her brain. But, if she hasn't had all the testing, perhaps there is something being missed.
It's horrible to see that sudden change. When my kids saw their grandfather, after surgery, they were stunned and they had a hard time comprehending the sudden change. We all did. My deepest sympathy for what you are enduring.
Carol
