Physical trauma to the head as well as the subsequent emotional/psychological state and stress that he could have experienced can all be related to this. For example,exposure to persistent severe stress states can cause actual damage to the brain http://news.stanford.edu/pr/96/960814shrnkgbrain.html
He may also be suffering from PTSD (he'd want to be evaluated for this face to face by a mental health professional)
Another possibility for the learning difficulty may be an actual case of LD (learning disability) or ADD. Cognitive behavioral therapy had been show effective in addressing the latter.
Supplementing with Omega fatty acids and amino acids has also been used along with Piracetam 800 (over t he counter)
Now, regarding treatment options, what has been found helpful is neurofeedback, EMDR (eye movement desensitization therapy) because of the neuroplasticity of the brain (resiliency) and ability to regenerate itself and establish new neural pathways.