<s>[INST] Just had a visit with my mom, who has dementia. While I was there, she was talking and stopped all of a sudden and stared down. Her eyes then rolled to the left and she went totally limp. I checked to make sure she was breathing and she was. She then jerked out of that and her arms became rigid and she was shaking. That passed, and she got really pale. The resident nurse checked her blood pressure, which was normal. What could possible reasons be for this episode? [/INST] Hello! Welcome on Chat Doctor ! Your mother symptoms could be related to an epilepsy seizure. From the other hand, many Chat Doctor.  For this reason, I recommend consulting with a neurologist and performing an EEG. Some blood lab tests are also necessary to exclude possible metabolic causes that may lead to seizures (complete blood count, blood electrolytes, thyroid hormone levels, kidney and liver function tests). Hope you will find this answer helpful! Best wishes,  </s>