CBIS CBIS Brain Injury Pathophysiology and Neuroscience 2 — Questions and Answers
Question 1: What is cerebral autoregulation?
- The brain's ability to generate new neurons after injury
- The automatic adjustment of cerebral blood flow to maintain stable perfusion despite changes in systemic blood pressure (Correct answer)
- The regulation of neurotransmitter reuptake at synapses
- The control of CSF production by the choroid plexus
Correct answer: The automatic adjustment of cerebral blood flow to maintain stable perfusion despite changes in systemic blood pressure
Cerebral autoregulation is the mechanism by which cerebral blood vessels dilate or constrict to maintain relatively constant cerebral blood flow across a range of systemic blood pressures.
Question 2: Which imaging modality is most sensitive for detecting diffuse axonal injury in TBI?
- Standard CT scan
- Plain skull X-ray
- MRI with diffusion tensor imaging (DTI) (Correct answer)
- Cerebral angiography
Correct answer: MRI with diffusion tensor imaging (DTI)
MRI with diffusion tensor imaging (DTI) is the most sensitive tool for identifying white matter tract damage and axonal shearing characteristic of DAI.
Question 3: What is the normal range of intracranial pressure (ICP) in adults?
- 0–5 mmHg
- 5–15 mmHg (Correct answer)
- 20–30 mmHg
- 30–40 mmHg
Correct answer: 5–15 mmHg
Normal ICP in adults ranges from approximately 5 to 15 mmHg; values consistently above 20 mmHg are considered elevated and require intervention.
Question 4: Which of the following best describes secondary brain injury?
- The immediate structural damage at the moment of trauma
- Physiological cascades such as hypoxia, hypotension, and cerebral edema that worsen injury after the initial event (Correct answer)
- Brain damage caused by a second independent traumatic event
- Axonal injury from rotational forces during impact
Correct answer: Physiological cascades such as hypoxia, hypotension, and cerebral edema that worsen injury after the initial event
Secondary brain injury encompasses the biochemical and physiological processes — including inflammation, excitotoxicity, and ischemia — that develop hours to days after the primary impact and compound neural damage.
Question 5: What is the primary function of the blood-brain barrier (BBB) relevant to TBI?
- To produce cerebrospinal fluid for cushioning the brain
- To selectively restrict passage of substances from the bloodstream into the brain, protecting neural tissue (Correct answer)
- To regulate cerebral blood flow velocity
- To filter metabolic waste products from neurons
Correct answer: To selectively restrict passage of substances from the bloodstream into the brain, protecting neural tissue
The BBB is formed by specialized tight junctions in cerebral endothelial cells that limit which molecules can enter the brain, protecting it from toxins and pathogens; TBI often disrupts this barrier, worsening edema and inflammation.
Question 6: What is post-traumatic amnesia (PTA) and why is it clinically significant for CBIS professionals?
- Loss of memories from years before the injury; indicates chronic CTE
- A period of confusion and inability to form new memories after TBI; its duration predicts injury severity and outcome (Correct answer)
- Permanent inability to recall autobiographical memories; specific to frontal lobe injuries
- Short-term memory loss caused by medication side effects post-TBI
Correct answer: A period of confusion and inability to form new memories after TBI; its duration predicts injury severity and outcome
PTA is a state of confusion and anterograde amnesia following TBI where the person cannot form continuous new memories, and its duration is a key predictor of overall injury severity and rehabilitation prognosis.
CBIS CBIS Brain Injury Pathophysiology and Neuroscience 2
What is cerebral autoregulation?