Delayed changes of vascular permeability in the cat's spinal cord following continuous electrical stimulation.

Liquefactive necrosis coexistent with alteration of vascular permeability was studied following electrical stimulation of the spinal cord. Evans blue albumen complex (EBA) (2.5%) was perfused one hour before electrical stimulation for 30 min with 10 mA current of 0.3 msec duration at a frequency of 20 Hz. Perfusion with saline and formalin was carried out at 0, 1, 3, 6 and 12 h after stimulation had been completed. Results were independent of the time lapse after completion of the stimulation. Liquefactive necrosis, swelling and moniliform degeneration and myelinoclasia of the myelin sheath were noted only in the external layer of the white matter. EBA leakage occurred, but there was no further expansion with time.