The most rapid improvement usually occurs in the first few months after injury, but no one can reliably quote a period of time when recovery stops. The rate of progress can vary greatly, depending upon the individual and on the time that has passed since the injury occurred. At times, progress can be frustratingly slow.

The best estimates for recovery are made after considering all the specifics of each individual's case and of his or her life before the injury. Some of the personal issues that are factored into a person's recovery include the individual's personality traits, physical health, intellectual level, as well as his or her age and the family and social support systems available. The medical issues involved in estimating recovery include the type of injury the person has sustained; the cause, location and severity of the injury; the amount of time spent in coma or post-traumatic amnesia; the care the person has received; and the amount of time that has gone by since the injury occurred.