Post-traumatic seizures exacerbate histopathological damage after fluid-percussion brain injury

The purpose of this study was to investigate the effects of an induced period of post-traumatic epilepsy (PTE) on the histopathological damage caused by traumatic brain injury (TBI). Male Sprague Dawley rats were given a moderate parasagittal fluid-percussion brain injury (1.9-2.1 atm) or sham surgery. At 2 weeks after surgery, seizures were induced by administration of a GABA(A) receptor antagonist, pentylenetetrazole (PTZ, 30 mg/kg). Seizures were then assessed over a 1-h period using the Racine clinical rating scale. To evaluate whether TBI-induced pathology was exacerbated by the seizures, contusion volume and cortical and hippocampal CA3 neuronal cell loss were measured 3 days after seizures. Nearly all TBI rats showed clinical signs of PTE following the decrease in inhibitory activity. In contrast, clinically evident seizures were not observed in TBI rats given saline or sham-operated rats given PTZ. Contusions in TBI-PTZ-treated rats were significantly increased compared to the TBI-saline-treated group (p