Neck Flexion Induces Larger Deformation of the Brain Than Extension at a Rotational Acceleration, Closed Head Trauma

Figure 3

Sagittal closed head rotational acceleration and pressure recordings in indicated regions of the brain during low and high level flexion ((a)–(d)) and extension ((e)–(j)), respectively. The recorded sagittal rotational acceleration rate is indicated by the black dashed line and the scale to the right in (a), (c), (e), and (h). (a) and (b) demonstrate that a low level flexion initially induced a strong underpressure, followed by slight overpressure. (c) and (d) show the strong pressures recorded at a high level flexion. Extension at a low level ((e)–(g)) generated initially overpressure followed by underpressure, thus strikingly differing from the pressure patterns induced by flexion at the same level ((a) and (b)). Pressure patterns at high level extensions are presented in (h)–(j). Three experiments were performed in 3 different animals, except for high level flexion. The largest change in peak pressures, the least change in pressure, and representative pressure time histories are presented. See Figure 8 for statistical analyses.

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