What alternative / complementary treatments do you recommend?

My son-in-law suffered a concussion after falling off his bicycle 9 months ago. There has been slow improvement but he is unable to return to school or work.

He has fuzzy head most of the time, can not be in noisy surroundings or with many people, is tired, can no longer sing or play an instrument, sleeps alot but has trouble sleeping at night, can't exercise, nor take buses, is tired after walking a few blocks, etc. We have seen some minor improvement, but....

The neurologist says that it may just take time and more time.

What can we do to nurture the process?

He has tried cranio-sacral therapy, seen an oesteopath, increased his vitamins. We are considering hyperbaric oxygen therapy.

Please, any guidance, you can give will be much appreciated.