a-marathon-runner-presents-confused-and-has-a-seizure-after-drinking-excessive-p

Question

A marathon runner presents confused and has a seizure after drinking excessive plain water during the race. Which of the following analyses best identifies the most likely primary diagnosis and immediate pathophysiologic cause?

Accepted Answer

Exercise-associated hyponatremia due to ingestion of excessive hypotonic fluids diluting ECF sodium, causing water to move into brain cells and resulting in cerebral edema and neurologic symptoms

Answer

Hypoglycemic seizure due to inadequate carbohydrate intake during endurance exercise rather than any fluid or electrolyte disturbance, which is the most common cause of seizures in marathon runners

Answer

Heat stroke from hyperthermia causing breakdown of the blood–brain barrier independent of sodium changes and leading to seizures because plasma sodium is typically elevated in this condition

Answer

Severe dehydration causing hypernatremia and intracellular dehydration of neurons, with seizures due to neuronal shrinkage rather than swelling