Effect of prolonged convulsions on the blood-cerebrospinal fluid barrier.

The effect of prolonged convulsions (induced by Metrazol or electroshock) on the blood-cerebrospinal fluid barrier of puppies was evaluated with the use of radioiodinated human serum albumin by measuring its rate of passage from the plasma into the cerebrospinal fluid. Albumin I131 was injected intravenously and convulsions were induced immediately by intravenous Metrazol or the application of electroshock. A marked increase in the concentration ratio (cerebrospinal fluid radioactivity/ plasma radioactivity) occurred when seizures were maintained for 30 minutes or longer. The slope of cerebrospinal fluid albumin I131 concentration as a function of time was about 25 times as great in the convulsed puppies as in the controls. It is concluded that marked alteration in the permeability of the blood-cerebrospinal fluid barrier to albumin I131 was produced by prolonged seizures.