There are therapies you can do that have been demonstrated in studies to assist in rehabilitating brain injuries. I encourage you to research into these with your parents.

The first therapy is Neurofeedback. Traditional neurofeedback, which has been around since the 1970's, has been shown to improve symptoms by 80% in studies. The LENS neurofeedback system, which is an advanced form of neurofeedback, has a much higher success rate, and it is currently being investigated as a treatement modality for Iraqi/Afghanastan war veterens who incured TBI's. The caveat to neurofeedback is to make sure you find someone who has experience treating brain injuries.

The second therapy is Hyperbaric Oxygen Therapy (HBOT). It has been studied before with mixed results and more studies need to be done to verify its effectiveness. This is currently being studied at The University of Utah School of Medicine for treatment of TBI. They are speculating that this assists in the repair of damaged tissue via neural stem cells and also activates idiling neurons that aren't receiving adequate blood supply. If you live in the area, you may want to contact them for participation.

Nootropics, to include oxiracetam, aniracetam and pararacetam, have been shown in studies to improve cognitive ability in people with head injuries. You can get them online from supplement companies. Another drug that has been studied with some success is cerebrolysin.

The fourth therapy would be any form of meditation. Meditation has been shown in SPECT scans to increase blood flow to the brain, especially the frontal cortex.

The fifth therapy is Vision Therapy. If you are having vision problems, you may want to look into this as a therapy.

There are also others, such as Transcranial Magnetic Stimulation, Chiropractic manipulation, and cranial sacral therapy, but that have been anecdotally shown to be beneficial. However, there still needs to be more research done on these.

Be careful with medication because researchers are now speculating that medication, such as anti depressants and stimulants, can actually be harmful to an injured brain in the long term, and current studies are underway to investigate this. So, if you are on medication, or your doctor wants to put you on any, you may want to discuss with him the possible risks associated with these.

Of course, as others have mentioned, diet, exercise, vitamins/minerals, and hormones are all important as well.

The good news is that your brain is young and as a result, you should have not problem rehabilitating it using one of the methods described above. Rest and a low stress enviroment are very important, but if you haven't improved after 6 months post injury, you need to enroll in a treatment program.

Good luck.