EARLY ASSESSMENT OF NEUROLOGIC DEFICITS IN THE FLUID PERCUSSION MODELOF BRAIN INJURY

This study was designed to quantify the early neurologic effects of br ain injury elicited by fluid percussion to the dura of cats. Propofol was used for surgical anesthesia because recovery in normal animals fr om an intravenous infusion was found to be nearly complete within 2 h of cessation and absolutely complete by 4 h. In addition, a cat coma s cale (CCS) was developed that reflects normal (CCS, 14) to moribund (C CS, 3) behavior. The CCS values at 6 h were compared with the force of injury expressed in atmospheres (atm), maximum blood pressure change, and gross neuropathology to ascertain which parameter might best acco unt for the behavior observed after brain injury. The results showed t hat decreasing neurologic scores correlated well with increasing atmos pheres of injury (Pearson's r 0.71, p < 0.001) but not with the rise i n systolic blood pressure caused by the trauma (n = 29). Coma scores d id correlate with the cross sectional area of pontomesencephalic lesio ns (Pearson's r = 0.51, p < 0.01) and proved to be significantly diffe rent in animals grouped according to lesion size of less or more than 3 mm in length (t test, p < 0.01). Thus the CCS and the pharmacologic properties of propofol permit an early analysis of the neurologic stat us in the feline fluid percussion model of brain injury. These procedu res could facilitate the evaluation of early biochemical changes that affect behavior and of therapies designed to ameliorate the deleteriou s effects of head injury.