PLAT and Stroke: However, some nurses disagreed or were neutral about the need to assess stroke severity by applying the NIHSS (M = 3.19, SD = 1.76), obtaining NIHSS 24 h post-tPA administration (M = 3.21, SD = 1.69), obtaining NIHSS scores before conducting a procedure (M = 3.18, SD = 1.65), and obtaining NIHSS scores after conducting a procedure (M = 3.30, SD = 1.63).