Hello and welcome to Healthcare Magic. Thanks for your query.
I'm sorry to hear about your sister's health condition. The prognosis or recovery from post-traumatic amnesia
) is very variable and depends on the severity and extent of the brain injury
. But usually, if the memory loss has not improved much in the first few days or months, then the chances of reversal are grim.
Medical marijuana does not have any proven role in improving memory or congitive deficits. One option which you can try is cognitive rehabilitation
therapy or cognitive re-training.
Wish you all the best.
Dr. Jonas Sundarakumar