RecruitingDevice studyPercutaneous Electrical Nerve Field Stimulation (PENFS) in Patients With Post Concussion Syndrome (PCS)The purpose of this study is to test the effect of Auricular Percutaneous Electrical Nerve Field Stimulation (a Neurostim device) on children with pain and Post Concussion symptoms. An additional purpose of this study is to demonstrate that PENFS improves functioning in children with post Covid-19 symptoms.