[Cerebrovascular complications of sickle-cell anemia].
Cerebrovascular disorders are frequent in sickle-cell anemia. They occur mainly in homozygous children. Traditionally, they were believed to result from an arteriolar sickle-cell thrombosis, the "sludge" phenomenon, which is generally responsible for sickle cell anemia disorders. It is now well known that several other kinds of cerebral damages are involved such as moya-moya syndrome, cerebral hemorrhage, subdural hematoma, extra-dural hematoma and cerebral thrombophlebitis. In this disease, the identification of these different processes cannot be always made by a simple clinical examination. However, specific therapies are sometimes necessary, such as neurosurgical intervention in the case of aneurysm or hematoma, and, according to some authors, the necessity of repeated appropriate transfusions, in the case of moya-moya. So it is imperative to carry out without delay a complete neuroradiological assessment of the lesions. At present, the most widely accepted theory to explain the arteriolar lesions, is that they result from a sickle-cell thrombosis of the vasa-vasorum, but, we think it is not the only valid hypothesis and we think that other phenomena may be involved with a genetic factor (patients with connective tissue disorders may have a particular genotype), and with infectious or autoimmune or coagulation disorders, the latter being frequently observed in this disease.