Focal or partial seizure in pit bull/rottweiller?

My son's 2 year old cross dog is having very minor (seizures?). They happen usually at night. He is laying down and then has little rapid movements of his head. This lasts for about 20 seconds and he is totally responsive during this time and will come to him when called. He had been put on seizure med, but after 2 weeks, the seizures did not change. He has slightly elevated WBC count. Does anyone have any answers???? HELP PLEASE!