CBIS CBIS Brain Injury Pathophysiology and Neuroscience 1 — Questions and Answers
Question 1: What is 'primary brain injury' in the context of traumatic brain injury (TBI)?
- Damage caused by secondary complications like swelling
- Immediate mechanical damage occurring at the moment of impact (Correct answer)
- Injury resulting from inadequate oxygen delivery
- Neural damage caused by excitotoxic neurotransmitters
Correct answer: Immediate mechanical damage occurring at the moment of impact
Primary brain injury refers to the immediate, direct mechanical damage to brain tissue that occurs at the moment of the traumatic impact.
Question 2: Which brain region is most critically associated with memory consolidation and is frequently damaged in TBI?
- Cerebellum
- Basal ganglia
- Hippocampus (Correct answer)
- Occipital lobe
Correct answer: Hippocampus
The hippocampus plays a central role in consolidating short-term memories into long-term storage and is highly vulnerable to TBI-related damage.
Question 3: What does the Glasgow Coma Scale (GCS) measure in TBI patients?
- Brain metabolic activity via PET scan
- Level of consciousness through eye, verbal, and motor responses (Correct answer)
- Degree of intracranial hemorrhage on CT imaging
- Post-traumatic amnesia duration
Correct answer: Level of consciousness through eye, verbal, and motor responses
The GCS assesses a patient's level of consciousness by scoring eye opening, verbal response, and motor response, with a total range of 3–15.
Question 4: What is diffuse axonal injury (DAI)?
- Focal bleeding in the subdural space
- Widespread shearing of axons throughout the brain caused by rotational forces (Correct answer)
- Localized neuron death from ischemia
- Swelling confined to a single brain lobe
Correct answer: Widespread shearing of axons throughout the brain caused by rotational forces
DAI results from rotational acceleration-deceleration forces that shear axons broadly across the brain, often causing prolonged unconsciousness without visible focal lesions.
Question 5: Which neurotransmitter is primarily implicated in excitotoxicity following a TBI?
- Dopamine
- Serotonin
- Glutamate (Correct answer)
- GABA
Correct answer: Glutamate
After TBI, massive release of glutamate over-stimulates NMDA receptors, flooding neurons with calcium and triggering excitotoxic cell death.
Question 6: According to standard clinical criteria, which combination defines a mild TBI?
- GCS 3–8, loss of consciousness >24 hours, PTA >7 days
- GCS 9–12, no loss of consciousness, PTA <1 hour
- GCS 13–15, loss of consciousness <30 minutes, PTA <24 hours (Correct answer)
- GCS 13–15, loss of consciousness >1 hour, PTA >7 days
Correct answer: GCS 13–15, loss of consciousness <30 minutes, PTA <24 hours
Mild TBI is defined by a GCS of 13–15 at presentation, loss of consciousness of 30 minutes or less, and post-traumatic amnesia lasting less than 24 hours.
CBIS CBIS Brain Injury Pathophysiology and Neuroscience 1
What is 'primary brain injury' in the context of traumatic brain injury (TBI)?