My Mother Who Is 72 Yrs Old Had A Fall

my mother who is 72 yrs old had a fall in toilet in last april. she had vertebral fracture for which she was for a months rest. she is hypertensive and on medication . earlier she was taking disprin but has stopped for last 2 to 3 months. she also had a surgery for hernia , a year back. she is also having slight hypothroidism. since 10 days she has started talking irrelevent talk. repeats the same thing often and for
the rest of the day she is ok. she was on pain killers for last one month for her arthritis treatment. but now she has stopped it. what could be the reason for her irrelevent talk.