Mother has had short seizure like blackouts over last 6 weeks. She is 76, went to ER tues night, because she had one that eve about 5;30 in front of me that lasted about 20-30 seconds. She the said she had one earlier and then she had one about 5-10 secs in the car on the way to the ER. They did EKG, MRI/brain, EEG, and echocardiogram. All negative per ER doc and the consulting neuro. They discharged her tonight with a heart monitor until Friday, and she has to go back for MRI on carotid when they can schedule her in. ER thought it might be low BP, neuro thought might be brain, but all tests so far negative. She takes high bp med, atavastin for cholesterol, a diuretic, and an osteo arthritis drug, plus vitamins. They don’t think it is side effect. My question; what are other possibles if all these test are negative?