Brain tumor help

Hi, I am hoping someone maybe able to help me. Two weeks ago, my husband was in a single car accident, however, he sustained no injuries from the accident. He apparently had seizures which were the cause of the accident. The cause of the seizures was found to be a brain tumor in his right frontal lobe that has since been removed. The tumor, called an Astrocytoma, is unfortunately malignant...it is a mostly stage 2 with small sections of stage 3. The really strange thing is that he had no symptoms of any kind, before the accident. He had never had a seizure before, and he only got the occasional migraine (maybe 1 per year), these run in his family, so the one that he had about six months ago, did not seem unusual in any way. He has had no personality changes before or after surgery. It's not a situation where you look back and notice signs you've been missing...there just weren't any! He has never smoked, and has always been healthy and active. He is a Diesel Mechanic however, and does work extensively on Diesel engines. He has also worked extensively in 'generator rooms', which generate electricity for oil rigs etc. His sleep patterns are normal, and his only allergy is to shell fish. The only time in his life he has been sick, was when he had mild shingles for about a week (7 years ago). Kind regards, Kitty.