What Do My Blood Test And MRI Results Showing Mild Cortical Changes And A Slightly Elevated Hemoglobin A1C Mean, And Are They Serious?

Hello, I’m a 30 year old male; two months ago I suffered a little accident at my home (I was assembling a rack and a part of it hit the back of my head) but I didn’t have any serious symptoms of concussion just drowsiness, loss of balance/dizziness and pain behind my eyebrows. Just to be safe that my brain didn’t suffer at all due to this incident, I went to a doctor and he sent me to perform a blood test and an MRI. The blood test says that I have a 5.8% hemoglobin A1C. The MRI says the following “Mild age advanced cortical involutional changes are present, most pronounced in the biparietal regions”. What do these diagnostics mean? Are they serious? PD: I have never consumed alcohol in my life nor I’m a smoker.