Significance of the Tentorium in Head Injuries from Blunt Forces

Mechanism of Injury to the Corpus Callosum, With Particular Reference to the Anatomical Relationship Between Site of Injury and Adjacent Brain Structures

“…12,13) However, these mechanisms are not consistent with more recent experimental evidence. In an experiment using a gelatin model, shear strain tended to concentrate on the boundary between heterogeneous tissues.…”

An Unusual Syndrome of Pediatric Brainstem Trauma

“…Such lesions may also arise secondarily from the effects of hypoxic brain injury, posttraum atic edema, posttraum atic vasospasm, or, most dramatically, trans tentorial herniation [24], It has generally been observed that primary brainstem lesions, in the absence o f signifi cant complicating factors such as tentorial herniation, consist o f small hemorrhages most commonly dis tributed from the caudal mesencephalon to the mid pons. Lesions tend to occur laterally in the basis pontis and lateral mesencephalic sulcus, as well as periventricularly from the colliculi to the pontine tegmentum [2,22,30,31,36]. There is microscopic evidence to suggest that lateral hemorrhages arise from small arterial and possibly capillary tears, whereas the periventricular lesions may be a result of venous disruption [26].…”

“…There is microscopic evidence to suggest that lateral hemorrhages arise from small arterial and possibly capillary tears, whereas the periventricular lesions may be a result of venous disruption [26]. Mechanical factors contributing to direct brainstem in jury include contusion o f the brainstem via fracture of or collision against the clivus, and impact o f the dor solateral pons against the tentorium [24], The role of the tentorium in such injuries has been noted by Lindenburg [22] to be similiar to the 'Kernohan's notching' seen with expanding supratentorial lesions, although the brainstem injury presumably occurs on a much faster time scale. Less commonly, actual laceration of the brainstem can occur from basal skull fractures and hyperextension-induced separation at the pontomesen cephalic or pontomedullary junctions [4,23].…”

“…Caudal shift of the upper brainstem tends to produce lesions that are generally larger than seen with primary brainstem inju ry, but which vary considerably in both extent and loca tion [6,32]. The most common site o f such hemorrhages is the rostral brainstem, principally confined to the mid line, although confluent lateral extension can occur [21,22]. The arterial nature o f these various lesions has been supported by the absence o f prominent venous conges tion [22] and postmortem injection showing actual ar terial tears [20].…”

“…The most common site o f such hemorrhages is the rostral brainstem, principally confined to the mid line, although confluent lateral extension can occur [21,22]. The arterial nature o f these various lesions has been supported by the absence o f prominent venous conges tion [22] and postmortem injection showing actual ar terial tears [20]. Fixation of the basilar artery by the carotids during downward migration of the brainstem may result in tears at the level o f midbrain and pontine perforating arteries.…”