Lack of clarity regarding the definition of mild or improving stroke symptoms also appears to be a barrier to tPA use. One study found that the most common reasons for exclusion from tPA treatment, aside from arriving beyond3 hours of symptom onset, were mild neurological impairment and rapidly improving symptoms (Katzan et al. 2004). Isengger et al. (20006) also cited mild or rapidly improving symptoms as a common criterion for exclusion from tPA treatment. One retrospective study of 255 stroke patients found that 37% were excluded from tPA therapy because of minimal weakness or improving symptoms; however, the outcomes for these patients were not discussed (Asimos et al. 2004). A study 0f 2,165 stroke patients found that mild stroke accounted for 13.6% of tPA exclusions and that rapid clinical improvement accounted for 18.2% of exclusions. Of these patients excluded from tPA therapy because of mild or improving symptoms, 32% either remained dependent at hospital discharge or died during hospital admission (Barber et al. 2001). Another study found that 25.4% of in-time arrivals were excluded from tPA therapy because of mild or rapidly improving symptoms. Only 66% of these patients were documented as both discharged to home and capable of independent ambulation (Hills & Johnston, 2006). These results bring into question the definitions of mild symptoms and improving symptoms. In addition, Baumann et al. (2006) found positive outcomes in patients treated with tPA despite improving symptoms.