Google is my friend today. I found this blurb on a website:
Dogs that have epilepsy, and periodically convulse, are often more aggressive in the immediate post-seizure phase before they have fully returned to normal. Dogs in this state should always be handled cautiously as they are not fully aware of what they are doing.
Aggression is also sometimes associated with partial seizures. In this type of seizure the dog does not go into convulsions but remains relatively lucid and yet can display aberrant behavior.
Partial seizures occurring in a region of the brain that controls aggression (e.g. hypothalamus or limbic system) can result in sudden unprovoked aggression. Certain breeds of dogs are known for this sudden, haphazard, and sometimes violent form of aggression. Included are: Springer spaniels, cocker spaniels, Chesapeake Bay retrievers, bull terriers, poodles, and golden retrievers. The clinical signs of seizure-related aggression are completely different from any of the other types of aggression mentioned above. They are as follows:
A mood change just before the seizure.
Sudden violent aggression for trivial or no reason.
Signs of autonomic discharge (salivation, dilated pupils, and evacuation of anal sacs).
Aggressive posturing, more or less continuous during an attack lasting several minutes, hours or even days.
Following a bout, affected dogs often appear depressed and lethargic, unresponsive to commands, and may stare at a wall or simply sleep. An electroencephalogram (EEG) will often demonstrate abnormalities. Some dogs with this type of aggression may respond to treatment with anti-convulsants (e.g. phenobarbital).
Source: Medical Causes of Aggression In Dogs
This is Atlas to a freaking T (aside from the evacuation of the anal sacs). I've never seen him have an actual seizure, but I have watched him be completely fine with a group of people (while muzzled) for hours. Then suddenly, Atlas will begin to squeal like you're ripping his legs off and lunge at the nearest set of legs. Then, he'll be completely fine again and just go to sleep. His squeal is actually unnerving... it's kind of a cross between a bark and the sound a dog makes when in pain. Here is a picture of him with his group of soldier buddies. None of them are even remotely afraid of him, so I've been taking advantage of that fact to socialize my dog. He wears a muzzle and when he has a mental break, they don't even flinch. I find that is very helpful for Atlas, because it's a calm environment. If people are afraid of him, he gets edgy.
Not long after this picture was taken, he started screaming and lunged at the guy's leg in the striped shirt who isn't even looking at him, basically hitting his face against the guy's leg. The guy actually ignored him through the entire episode because it's not like Atlas can do any damage with his muzzle, and then Atlas immediately laid down beside me and just cried until I took him upstairs to bed.
I guess I can add an epilepsy test to my list of things to ask about. Can a vet do that, or is that a job for a neurologist?