“…Most studies have suggested that cognitive deficits occur shortly after injury with the impairment usually dissipating at 1-3 months post injury (Belanger, Curtiss, Demery, Lebowitz, & Vanderploeg, 2005;Dikmen, McLean, & Temkin, 1986;Frencham, Fox, & Maybery, 2005;Levin et al, 1987b;Ponsford et al, 2000;Rohling et al, 2011;Schretlen & Shapiro, 2003). Still other, often smaller, studies have shown that persistent impairment can be present in patients with mild TBI (Barth et al, 1983;Bernstein, 2002;Kwok, Lee, Leung, & Poon, 2008;Leininger, Gramling, Farrell, Kreutzer, & Peck, 1990;Ruff et al, 1994;. Impairments in a range of cognitive domains at long-term follow up have been documented after mild TBI, (Konrad et al, 2010) with most deficits involving attention and concentration Kwok et al, 2008;Ruff et al, 1994), memory, (Barth et al, 1983;Bernstein, 2002;Dikmen et al, 1986;Frencham et al, 2005;Leininger et al, 1990) speed of information processing , verbal fluency (Kwok et al, 2008), and executive functions Levin et al, 1987b).…”