What Causes Transient Ischemic Attack?

My husband had a t I a 7 years ago.the emergency room doctors and neurologist said they could not explain it. His blood pressure was up it was 140 over 100 but they said not high enough to cause it. The night before his t I a he was indoors with no ventilation painting a room ,and came home with a horrible headache,with what we found out 2days later was garage floor paint. The whole empty house smelled horrible for months. The warnings on can said it could cause neurological problems etc without proper ventilation. Do u think it could be possible that is was what triggered the Tia.