A: You may use codes 161002.2 through 161006.3 when the MD confirms “positive LOC”. This does not have to be witnessed by the MD. If they believe there was LOC and document it, we may code it. We do not need to have the word “concussion” in the chart in order to code LOC. If the EMS agency notes LOC, the physician must corroborate this finding in the medical record for you to code it in AIS.