Therapy study on the experimental injury of spinal cord. IV. High doses of methyl-prednisolone

The effect of large glucocorticosteroid hormones administered to two groups of adult rabbits with an experimental acute injury of the spinal cord was studied. In the former (10 rabbits), each animal received intravenous 30 mg/kg body weight of prednisolone-21-sodium-hemisuccinate after 30 minutes and further 15 mg/kg b.w. at intervals of 2, 24 and 48 hours since injury. In the latter (40 rabbits), each animal received 15 mg/kg b.w. methyl-prednisolone-21-hydrogen-sodium-hemisuccinate at 30 min, 2, 24 and 48 h postinjury. A group of 20 injured rabbits with the same experimental conditions was used as controls without glucocorticoid treatment. Clinically, both treated groups of rabbits showed a significant improvement of posterior limb movements and in the general state of health compared with the controls. The mean motor score (according to a 5-score scale) indicated a significant difference between the two treated groups (2.3 and 2.6, respectively and 1.7 for the controls). Histologically, the modifications correlated with the clinical posttraumatic symptomatology and severity in all the three groups: histopathological modifications consisted in oedema, ischaemic cells, diffuse microglial hyperplasia, microhaemorrhages, all of them located in the central gray matter. In all cases with a severe clinical evolution (score of 1-3), aggravated histopathological modifications both in the gray and white matter are evidenced: necrosis; vacuolization; cavitation; myelinic and axonal fragmentation, demyelination, mesenchymo-glial scar reaction. In all groups, regenerated nervous fibres were noticed in the dense scar of the injured cord.