What Does This Brain CT Scan Result For Persistent Headache And Memory Loss Indicate?

I was deployed to Iraq in 2007, I had a mortar explode very closely to me while I was there. I do not really remember what happened immediately after the attack one minute I was standing next I was on the ground. I did not seek treatment in country however, Since then I have had consistent headaches (at least once a week), memory loss, occasional numbness in fingers and toes, and dizziness. I saw my VA doctor about two weeks ago. He stated it sounded like TBI. He ordered a CT scan and. The impression that was given with the results stated Small CSF Attenuation Arachnoid cyst in the posterior fossa Then listed a primary diagnostic code of minor abnormality. My main question is basically could the mortar attack caused this? Is this considered TBI? finally what kind of treatment path am I looking at? I have a consult with polytrauma and a neurologist within 2 weeks I am just trying to be well informed for that appointment.