There are a number of homeopathic remedies for concussion and other ailments related to brain injuries. Here is a link to a study that examined the clinical effectiveness of homeopathic treatment for persistent mild traumatic brain injuries. The results of the study "indicate significant improvement from homeopathic treatment versus the control and translate into clinically significant outcomes". Even people who had suffered brain injuries years before the study experienced significant improvement. Furthermore, some who had been unable to work for years were able to return to work.
http://www.ncbi.nlm.nih.gov/pubmed/10671699
