Which autonomic and behavioral complications commonly occur in the acute phase after TBI?

• A. Agitation, delirium, dysautonomia with instability in heart rate and blood pressure; fever; irritability.
• B. Hypersomnolence and bradycardia only.
• C. Euphoria and hyperactivity with stable vitals.
• D. Seizures exclusively with no autonomic changes.

Answer: (A)

In the acute phase after traumatic brain injury, the brain’s control of autonomic function and behavior is disrupted, producing a characteristic cluster of signs. Agitation and delirium are common as brain networks that regulate attention, arousal, and impulse control become unstable, and environmental factors or medications can amplify this. Dysautonomia often appears as labile heart rate and blood pressure, sometimes accompanied by fever, reflecting disruption of brainstem and diencephalic autonomic control. Irritability is another frequent behavioral reaction, stemming from impaired emotion regulation tied to frontal and limbic circuit disruption. This combination captures both the autonomic instability and the behavioral changes seen early after injury.

The other choices don’t fit as well because they describe too narrow or atypical patterns. Hypersomnolence and bradycardia alone miss the common agitation, delirium, and fluctuating vitals with fever. Euphoria and hyperactivity with stable vitals don’t align with the typical acute autonomic instability and behavioral dysregulation. Seizures can occur after TBI, but they are not exclusively present with no autonomic changes, and relying on that pattern ignores the frequent autonomic and behavioral abnormalities seen early.