Any Suggestion For Having Calcified Healed Granuloma In Right Frontal Lobe?

My son is now 17 years old studying in XII std. He had a brief absence seizure three years back but recovered in a few seconds.The docs adviced an EEg which was found normal. Thereafter we ignored the episode and nothing happened till now when on 24 Sept he met with an accident and sufferred head injuries. He was iunconsious for a few minutes and when came in senses he had diffiuculty in his memory. Every time he looked away from me he forgot that I was there and asked the same question again and again that " HI DAD WHAT HAPPENED. WHY THIS BLOOD ON MY SHIRT." His CT Scan revealed a " CALCIFIED HEALED GRANULOMA IN RIGHT FRONTAL LOBE" Thereafter the MRI (Contrast done on 07 Oct had revealed calcified inflamatory granuloma in right frontal lobe. But the EEG got done on 8 Oct. didnot suggest ant abnormality. Now the Docs have placed him on LEVEFREE 500 mg. BD dose due to which he is not able to concentrate on his studies this year being crucial for his NON-MEDICAL pursuit. Kindly suggest.