Effect of cerebellar ablation on the high pressure nervous syndrome in rats

To evaluate the interaction between high pressure nervous syndrome (HPNS) seizures and cerebellar integrity, seizure threshold pressure (Pc) of normal rats was compared with that of rats sustaining cerebellar ablation two weeks prior to exposure to 136 ATA in a helium-oxygen atmosphere. All rats exhibited severe HPNS symptoms which culminated in seizures. Pc was reduced in cerebellectomized animals, and the number of seizure episodes increased twofold, but the average duration of seizure episodes was unchanged. The spike-and-wave pattern in the electroencephalogram remained a prominent feature in both groups.