ICS-TBI Flashcards
A 37 year old man fell asleep at the wheel and got in an accident. He hit his head and lost consciousness for about 40 minutes. Did he have a TBI? How do you proceed forward?
Yes he had a TBI. A TBI is a traumatically-induced physiologic disruption of brain function temporarily or permanently. He needs to be evaluated by a brain specialist.
What are acute indicators of TBI
Loss of consciousness, alteration of consciousness (dazed/confused), post-traumatic amnesia (anterograde or retrograde), skull injury and constitutional symptoms.
What severity of TBIs are most common in the US and in the military population?
Mild TBIs (most in non-combat environments)
Causes of TBI
Blunt force (contusions near site of impact), rapid acceleration-deceleration injury (contusions at site of impact and opposite side), angular rotation of brain, explosive blast (diffuse force from blast), herniation (compression of brain tissue) and projectile injuries
What is your diagnosis?
Contusion. This is a superficial bruise confined to the gray matter of the brain.
Where are the major lesions in patients who experience a rapid acceleration-deceleration lesion?
The area opposite the side of the impact
A traumatically induced physiologic disruption of brain function characterized by confusion, disorientation for < 24 hours. LOC for 30 min. Memory loss < 24 hours. Normal MRI/CT.
Concussion (mild TBI)
What happens physiologically after you have a concussion?
Injured axon -> K+ release -> Depolarization -> Glutamate release -> AMPA receptor activation -> Ca2+ rushes in. This is characterized by an initial hyper metabolism of glucose followed by hypo metabolism of glucose that can last several days.
A former football player presents with uncharacteristic outbursts of anger, short-term memory problems, decreased complex thinking, difficulty concentrating, loss of organizational and planning skills and apathy. Later when he died autopsy of his brain is shown below. What is causing his condition?
Chronic Traumatic Encephalopathy. Characterized by dementia, Parkinsonism and widespread accumulation of tau accumulation in the neurons of the hippocampus, amygdala, entorhinal cortex, neocortex, insular cortex and maxillary bodies (neurofibrillary tangles not seen on gross specimen)
What regions of the cortex tend to be involved in chronic traumatic encephalopathy?
Superficial regions
How does chronic traumatic encephalopathy get mixed up between psychiatrists and neurologists?
Neurologists = post-concussion syndrome. Psychiatrists = PTSD.
What type of brain injury is commonly present in people involved in TBIs with a rotational component?
Diffuse axonal injury. Technically this is specific for axonal rupture around the corpus callosum and midbrain tectum. Clinicians talk about widespread, more mild version.
When is the most optimal time to have a TBI?
Once the brain is done developing, but when you are still younger.
What’s the difference in symptoms between diffuse axonal injury and focal cortical injuries?
The cortex is kind of like the processor, so you get symptoms associated with information processing (aphasia, paralysis, amnesia, neglect). The axons are like the wiring, so you get symptoms associated with transmission (generalized deficits like poor attention, slowed processing speed, forgetfulness or fatigue)
Why is it difficult to diagnose diffuse axonal injury?
Injury is not shown on CT or MRI
Shortly after injury how does the brain adapt
Collateral sprouting of axons to reconnect vacant synapses, substitution of intact brain regions for infarcted regions, synapse super sensitivity of dendrites.
