Hello. Thank you for asking your question on just answer. My name isXXXXX will try to help.
How long ago did he have the seizure?
How long did it last?
Can you check the color of his gums please?
Is he having any other signs? Coughing, sneezing, vomiting, or diarrhea?
And how is he now?
When he had the seizure, had it been a while since he had anything to eat?
So hopefully he just had a seizure from low blood sugar. If it happens again, try putting a few drops of karo syrup, or pancake syrup on his tongue. If he had not eaten, I would go with the low blood sugar theory.
If it continues to happen despite a regular frequent feeding schedule, then you will want to take him to the vet for blood work.
Some other metabolic causes of seizures are low calcium, liver disease, and kidney disease.
Cardiovascular disease can also cause seizures. Cardiomyopathy is a fairly common occurance in cats. The vet will check his heart as well. This would be unlikely in an 8 week old kitten.
www.VeterinaryPartner.com/Content.plx?P=A&A=2420 feline cardiomyopathy
www.VeterinaryPartner.com/Content.plx?P=A&A=2507 hypertrophic cardiomyopathy
Genetic and idiopathic (unknown cause) epilepsy in cats is porrly documented but does occur in real life. Structural brain lesions are most common. They can be caused by bacteria, viruses, and post traumatic incidents. Brain tumors can occurs but are rare.
www.VeterinaryPartner.com/Content.plx?P=A&A=560 seizure disorders
I would also give him a few drops of the karo syrup, or pancake syrup, now just to make sure his blood sugar is up.
I hope this helps.