[Nuclear magnetic tomography in the differential diagnosis of syringobulbia and craniospinal tumors].

Though syringobulbia is a rare condition, the problem of its differentiation from other craniospinal abnormalities is a pressing one. This problem may be considered solved due to introduction of nuclear magnetic tomography (NMT). Studies carried out in 43 patients helped distinguish the NMT symptoms most characteristic of syringobulbia: a centrally located echo signal zone in the medulla oblongata and the cord, the echo signal in this zone being equivalent to that of the cerebrospinal fluid or gliosis, increased transverse size of the medulla oblongata and the spinal cord, dilated volumes of the basal cysterns. A craniospinal condition resultant from a tumor process is characterized by detection of a bulky formation with a heterologous structure in the medulla oblongata, involving the cervical portion of the cord and the cerebellar structures. It is associated with a perifocal edema and IVth ventricle deformation; this latter condition is often undetectable, and occlusive hydrocephalus develops. Since NMT often permits a differential diagnosis between syringobulbia and craniospinal tumors, it must become the method of choice in patients with these conditions.