traumatic brain injury

1. TRAUMATIC BRAIN
INJURY
Dr Abbas
Dr Gokul

2. EPIDEMIOLOGY
• MC Cause are falls, road traffic accidents &
assaults.
• Mortality between 25-30%

5. PRIMARY BRAIN INJURY
• It is the injury that occurs at the time of trauma, resulting
from various external mechanical forces transferred to
intracranial structures leading to bone fractures, contusions,
hematomas and axonal injury.
• The mechanisms commonly implicated in primary brain
injury include direct impact, rapid deceleration-
acceleration, penetrating injuries, shearing forces and blast
waves.
• The primary brain injury leads to disruption of blood brain
barrier and loss of cerebral autoregulation, causing
worsening of cerebral edema, increase in ICP and decrease
in cerebral perfusion pressure (CPP)

6. SECONDARY BRAIN INJURY
• Excitotoxicity: It is a series of events occurring
secondary to activation of neurotransmitters
leading to excessive stimulation of neuronal cells
and increasing neuronal damage.
• Free oxygen radical injury: Activation of
mitochondrial enzymes leads to development of
free radicals like superoxide ion and nitric oxide.
Lipid peroxidation also contributes to free radicals
induced neuronal damage.

7. • Activation of proteases
• Dysregulation of cell cycle and apoptotic pathwaY
• Disruption of blood-brain barrier may lead to
inflammatory response and vasogenic edema
leading to neuronal damage.
• Loss of cellular autoregulation
• Stress response to TBI may lead to catecholamine
surge and organ dysfunction

9. TYPES OF PBI
• Diffuse axonal injury (DAI) consists of diffuse punctate
lesions at the grey mater-white mater interface due to
axonal damage
• Epidural/extradural hematoma (EDH) between the inner
table of skull bone and the dura mater. It is lenticular in
shape and does not cross suture lines as the dura mater
is tightly attached to the skull bones. It commonly results
from rupture of the middle meningeal artery or its
branches associated with squamous temporal bone
fractures.

13. • Subdural hematomas (SDH) are hematomas which
develop between the inner surface of dura mater
and arachnoid mater and are crescentic in shape. It
results from rupture of bridging veins of the
cerebral surface or the dural venous sinuses.