Translational realistic expectations of chronic cerebral hypoxemia in rat model after bilateral commom carotid artery ligation. Neurocognitive aspects.

PURPOSE: To evaluate the effects of chronic cerebral hypoxia on memory of rats submitted to bilateral common carotid artery ligation (BCCL). METHODS: Every each week, for 16 weeks, 31 rats were tested for memory using a water and land mazes and compared with 30 normal rats (control group A). The variables were expressed by their mean and standard error of the mean (SEM). p<0.05 was used for rejecting the null hypothesis. The study was approved by the Ethics Committee for animal investigation. RESULTS: There was a significant increase in the latency time, in the survival water and land mazes, after four weeks (study group B) follow-up. However, without any medication or therapeutically induced measures, after 16 weeks (study group C) follow-up the latency mean times tend to be similar to control group (A) in the neurocognitive tests. CONCLUSIONS: Neurocognitive deficits after 16 weeks post-operative follow-up of rats that underwent bilateral common carotid artery ligation is a natural adaptive phenomenon. Thus, is not realistic to allow translational information from this animal model for therapeutically approaches aiming at to prevent, or to improve brain damage in human beings suffering from chronic deprivation of adequate blood supply.

Selective posterior rhizotomy: experience of 30 cases.

The increasing interest in selective posterior rhizotomy for reduction of spasticity in children with cerebral palsy and other neurological disorders comes from the selectivity that this procedure has achieved with intraoperative electromyographic monitoring. Thirty patients were operated on between April 1989 and October 1991. Spasticity was of cerebral origin in 27 cases and secondary to spinal cord lesion in 3 others. A reduction in the abnormally high muscle tone was observed in all cases, mainly in the lower extremities, but also, to a lesser degree, in the upper extremities. All patients showed functional improvements that depended on the individual preoperative condition. Even severely disabled patients with quadriplegia and intellectual impairment, whose spasticity interfered with their daily care, had a significantly improved quality of life after rhizotomy. These patients became much looser, with better swallowing and less drooling, and were much more easily managed by their caretakers. Preliminary results with follow-up from 1 to 30 months indicates that selective posterior rhizotomy is a safe procedure which contributes to significant functional improvement in spastic patients.