Page 835 - Robbins Basic Pathology by Vinay Kumar, Abul K. Abbas, Jon C. Aster

Concussion describes reversible altered consciousness Central Nervous System Trauma 821
from head injury in the absence of contusion. The charac-
teristic transient neurologic dysfunction includes loss of vessel, even in the absence of a skull fracture. In children
consciousness, temporary respiratory arrest, and loss and adults, by contrast, tears involving dural vessels almost
of reflexes. Although neurologic recovery is complete, always stem from skull fractures. Once a vessel is torn,
amnesia for the event persists. The pathogenesis of the blood accumulating under arterial pressure can dissect the
sudden disruption of nervous activity is unknown. tightly applied dura away from the inner skull surface
(Fig. 22–13, B), producing a hematoma that compresses the
Traumatic Vascular Injury brain surface. Clinically, patients can be lucid for several hours
between the moment of trauma and the development of neuro-
CNS trauma often directly disrupts vessel walls, leading to logic signs. An epidural hematoma may expand rapidly
hemorrhage. Depending on the affected vessel, the hemor- and constitutes a neurosurgical emergency necessitating
rhage may be epidural, subdural, subarachnoid, or intraparen- prompt drainage and repair to prevent death.
chymal (Fig. 22–13, A), occurring alone or in combination.
Subarachnoid and intraparenchymal hemorrhages most Subdural Hematoma
often occur at sites of contusions and lacerations.
Rapid movement of the brain during trauma can tear the
Epidural Hematoma bridging veins that extend from the cerebral hemispheres
through the subarachnoid and subdural space to the dural
Dural vessels—especially the middle meningeal artery— sinuses. Their disruption produces bleeding into the sub-
are vulnerable to traumatic injury. In infants, traumatic dural space. In patients with brain atrophy, the bridging
displacement of the easily deformable skull may tear a veins are stretched out, and the brain has additional space within
which to move, accounting for the higher rate of subdural hema-
tomas in elderly persons. Infants also are susceptible to

EPIDURAL HEMATOMA SUBDURAL HEMATOMA
Dura (peeled off skull) Dura (still attached to skull)

Skull fracture Venous
blood
Arterial
blood

A

BC

Figure 22–13 Traumatic intracranial hemorrhages. A, Epidural hematoma (left) in which rupture of a meningeal artery, usually associated with a skull
fracture, has led to accumulation of arterial blood between the dura and the skull. In a subdural hematoma (right), damage to bridging veins between
the brain and the superior sagittal sinus has led to the accumulation of blood between the dura and the arachnoid. B, Epidural hematoma covering a
portion of the dura. C, Large organizing subdural hematoma attached to the dura.

(B, Courtesy of the late Dr. Raymond D. Adams, Massachusetts General Hospital, Boston, Massachusetts.)