Pathological findings in suboccipital decompression in 63 patients with syringomyelia

Out of 97 patients with syringomyelia treated surgically, in 63 of them suboccipital decompression was performed. Various kinds of congenital or early acquired abnormalities were found to be the possible cause of the disease. Simple Arnold-Chiari malformation was found in 29 patients. In next 16 cases the Arnold-Chiari malformation was accompanied by partial occlusion of the foramen of Magendie with tiny, translucid membrane, that covered lower 1/2 or 3/4 of the foramen. In another 9 cases of Arnold-Chiari malformation, foramen of Magendie was totally occluded with thick, grayish membrane. In 7 cases lowered cerebellar tonsils were firmly attached to the medulla and joined by adhesions between themselves. In 1 case total atresia of foramen of Magendie was present only. In 1 case no pathological changes were found. The above mentioned findings point out, that in practically all the cases of syringomyelia various kinds of gross pathology, that leads to difficulties in normal outflow of the CSF from the IVth ventricle to cisterns can be found. From that point of view the suboccipital decompression seems to be the most reasonable surgical procedure.