From everything I've read, your neurologist's statement seems inaccurate. Look at all the athletes for whom recovery has taken a year or more: Corey Koskie, Mike Matheny, Justin Morneau, Sidney Crosby, David Perron, Patrice Bergeron, to name a few. Some returned to game action (Perron, Bergeron, Morneau), others have made a good recovery but chose to retire from playing sports (Matheny, Koskie), and others are not fully recovered but have continued to improve beyond the six-month mark (eg, Crosby).

Even on this site there have been people (me included) who have continued to improve beyond six months, and some who have made a decent recovery over a longer time frame. A friend who has had multiple concussions told me it took 14 months for her symptoms to go away after her last one (she's now doing well and, apart from some memory issues, is symptom-free).

This doesn't mean that a minority of people don't have lingering (even lifelong) symptoms, but I think six months is way too early to concede that no more progress will occur.