No, epilepsy originates in the brain in all cases. Different forms of epilepsy have different loci where brain neurons begin the misfiring that causes the seizure. From that originating locus the misfiring typically spreads out until much or all of the brain becomes involved in the seizure. Some forms of epilepsy are degenerative, some are not. But the cause and origin is always in the brain. If the form of epilepsy is degenerative, the degeneration of tissue will be in the brain.