The motion of the head and neck that occurs during a rear end collision when the impacted vehicle accelerates and the torso is pushed forwards by the seat back is defined as whiplash extension motion. Anaesthetised pigs were exposed to a swift extension-flexion motion of the neck while the pressure inside the spinal canal and the skull was measured. Plasma membrane dysfunction was indicated by the results from light microscopic analyses of the cervical and the three upper thoracic spinal ganglia revealing the staining of the nerve cells and satellite cells by protein complexed to the Evans Blue dye. The results verify a hypothesis by Aldman predicting that the volume changes inside the spinal canal during an extension-flexion motion of the cervical spine would result in transcient pressure changes in the central nervous system during a swift head-neck motion in the sagittal plane. Aldman also hypothesised that these pressure effects could induce injurious mechanical loads to the tissues inside the intervertebral foramina, and this agrees well with the histopathological findings of the present study.
Abstract