One of the most popular myths perpetuated by the media and some in the scientific community is that 15% of patients who have suffered a mild traumatic brain injury (MTBI) do not recover by one year and may even experience permanent symptoms. An important point that I try to teach people is to always obtain the original article that is cited in support of such claims so that the validity of the claim can be examined. In this case, the reference often cited is a 1995 study by neurologist, Michael Alexander. In his paper, he wrote the following: "At one year after injury approximately 15% of MTBI patients have not recovered’’ (p. 1256).

When researchers cite Alexander's study as the only reference for this figure, it casts the impression that he is the person who collected the data to support it. However, if one reads Alexander's paper, it is seen that Alexander based his 15% figure on two earlier studies: McLean and colleagues (1983) and Rutherford and colleagues (1979). To begin with, McLean and colleagues only followed 20 patients for one month not one year. In addition, his study consisted of 11 patients with MTBI, 8 patients with moderate TBI, and one patient with a severe TBI. One can hardly use a study of all severity TBI patients at one month post-injury to argue for the chronic effects of MTBI.

The main source of the myth, however, comes from Alexander's summary of the Rutherford article. Rutherford followed 131 MTBI patients for a year and he did indeed find that 19 (14.5%) complained of symptoms at that point. A detailed analysis of Rutherford's patients, however, reveals some interesting details. First, there were actually 145 patients in the study and of these, only 131 followed up. Assuming the missing 14 did not have symptoms one year post-injury, that changes the number to 13.1%. Of the 19 patients who were still reporting symptoms at one year, 8 were involved in lawsuits and 6 (5 of whom were in lawsuits) were suspected of malingering six weeks post injury. Malingering was defined in this study by: bizarre and exaggerated descriptions of symptoms and strange responses during routine examination. Can we really trust the self-report of symptoms in these individuals to be reliable and valid? The answer should be obvious.