[Porto-systemic encephalo-myelopathy].

To avoid the dangerous consequences of gastro-intestinal haemorrhages in portal hypertension, portosystemic anastomosis is often performed. These operations unfortunately cause numerous complications among which isolated encephalopathy and encephalo-myelopathy hold pride of place. In spite of their different clinical, biological, therapeutic and anatomo-pathological behaviour, these two complications are undoubtedly the result of a common pathogenesis of which the details are not at present understood. It is, however, known that these involve complex metabolic disorders connected with the direct passage into the caval blood of products from the gut (ammonia, false neurotransmitters, ...). Experiments with rats have shown development of type II Alzheimer glia in the cerebellum after portocaval anastomosis; so far, spinal lesions have not been reproduced (10-76). In conclusion, it must be recognized that, as Lucien Leger (39) wrote, "by creating a new physiopathology, portal decompression raises as many questions as it solves."