#june2020amc1
A 25-year-old man sustains an anterior skull base fracture. He had a CSF leak for 36 hours after the injury and was admitted for observation. Four days after injury he reports thirst and a frequent need to pass urine. On examination, the following is found: Blood pressure: 110/70. Pulse rate: 90 bpm. Oxygen saturation 100%. He appears well hydrated. Glasgow Coma Score is 15/15 and he has no neurological deficits, the CSF leak appears to have ceased. Which one of the following is the most likely explanation for his symptoms?
A. Cerebral salt wasting
B. Dehydration
C. Diabetes Insipidus
D. Occult CSF leak
E. Syndrome of inappropriate ADH (SIADH)
Explanatory Notes:
Diabetes Insipidus is characterised by large urine output and thirst. It is most common after anterior skull base fracture as in this scenario. Cerebral salt wasting (CSW) can occur in neurosurgical conditions but is associated with dehydration. SIADH causes water retention rather than loss. CSF leak in itself does not result in thirst and frequency. Dehydration would not be associated with a "well hydrated" appearance.
A 25-year-old man sustains an anterior skull base fracture. He had a CSF leak for 36 hours after the injury and was admitted for observation. Four days after injury he reports thirst and a frequent need to pass urine. On examination, the following is found: Blood pressure: 110/70. Pulse rate: 90 bpm. Oxygen saturation 100%. He appears well hydrated. Glasgow Coma Score is 15/15 and he has no neurological deficits, the CSF leak appears to have ceased. Which one of the following is the most likely explanation for his symptoms?
A. Cerebral salt wasting
B. Dehydration
C. Diabetes Insipidus
D. Occult CSF leak
E. Syndrome of inappropriate ADH (SIADH)
Explanatory Notes:
Diabetes Insipidus is characterised by large urine output and thirst. It is most common after anterior skull base fracture as in this scenario. Cerebral salt wasting (CSW) can occur in neurosurgical conditions but is associated with dehydration. SIADH causes water retention rather than loss. CSF leak in itself does not result in thirst and frequency. Dehydration would not be associated with a "well hydrated" appearance.
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