Dog aggression related to behavioral seizures has sometimes been called “Rage Syndrome”. It is often characterized by aggression directed toward family members in a dog who ordinarily seems perfectly normal. However rage syndrome may also be aggression that is actually owner-directed (formerly called dominance aggression) in which case there would be no evidence of seizures.
Partial seizures occurring in a region of the brain that controls aggression can cause sudden unprovoked aggression. There is a pre-aggression mood change, which last for minutes or hours before an attack and a post-aggression depression with reduced responsiveness. It is sometimes associated with compulsive behaviors, such as self-licking or snapping at imaginary flies.
There is some evidence that this aggression can be controlled with phenobarbital in some dogs. (1). If you suspect your dog having this kind of aggression where your ordinarily nice and friendly dog attacks, your vet should do a thorough clinical and neurological examination.