I just spotted your other post on this subject, if it's OK with you, since a number of replies have been made to this thread, I am going to delete the other thread since, even though it contains more information, it's basically a duplicate of this one.
Going by the information you gave in the other thread, I would say that the seizures should lessen as any injury to the brain heals. The seizures are due to the fact that there is some type of swelling or injury still going on in the brain from the injury, and once the brain returns to its normal state, the seizures should stop. HOWEVER, since there was a brain injury, this puppy MAY have epilepsy just as a result of the injury, but it's not a given that he will. He could be perfectly normal, but he could have intermittent seizures because of the injury, it's impossible to tell right now. You absolutely did the right thing by getting him to a vet immediately. Kudos to you for doing that.
Please keep us posted as to his progress.
Ghilly
Is your puppy under a vet's care? If he's experiencing seizures due to a head injury, depending upon the frequency and severity of the seizures, they sometimes will administer a tranquilizer to sedate the puppy to keep him calm until the brain has a chance to heal a bit.
What happened to him? Was he still with his litter when it happened? If not, is he orphaned? If not orphaned, why is a three week old puppy away from its litter? What breed of dog is he? Sorry to be pumping all these questions at you, I'm just looking for information to be better able to give you a more accurate response.
Ghilly
Sorry I didn't mean "people", I meant dogs.
A head injury may cause damage both from the direct physical injury to the brain and from secondary factors, such as lack of oxygen, brain swelling, and disturbance of blood flow. Both closed and penetrating head injuries can cause swirling movements throughout the brain, tearing nerve fibers and causing widespread bleeding or a blood clot in or around the brain. Swelling may raise pressure within the skull (intracranial pressure) and may block the flow of oxygen to the brain.
Head trauma may cause a concussion, in which there is a brief loss of consciousness without visible structural damage to the brain.
Epilepsy occurs in 2–5% of those who have had a head injury; it is much more common in people who have had severe or penetrating injuries. Most cases of epilepsy appear right after the accident or within the first year, and become less likely with increased time following the accident.