It's fortunate for people who have suffered a concussion or a mild traumatic brain injury that the symptoms generally will improve within the first month. In fact, about 50% of people will actually have their symptoms improve dramatically within the first month. But there are people where those symptoms simply don't get better and when these symptoms persist the doctor will make a diagnosis of post-concussion syndrome.
Doctors tend to use one year as a period of time to determine if the symptoms are actually permanent. So, beyond a year, the physician is really expecting that the symptoms are not going to get better or if they do they are only going to improve mildly. So, post-concussion syndrome is that point where the symptoms have become a permanent diagnosis of the patient. These need to be treated and evaluated by someone who is knowledgeable about what to do with that diagnosis.