[Syringomyelia, a neglected differential diagnosis in multiple sclerosis. 6 cases from a specialty clinic for multiple sclerosis].

During the last 5 years 11 patients with syringomyelia have been found among 4348 patients (0.25%) entering our hospital, which specializes in multiple sclerosis. Six of these 11 patients had been diagnosed earlier as suffering from multiple sclerosis, some of them after a protracted course of neurological illness. In all 6 patients examination of the cerebrospinal fluid was normal, and visual-evoked potentials (VEP) were normal in all but one case, which is described in detail as case 2 in this report. Magnetic resonance imaging (MRI) showed a Chiari malformation in 3 of 6 syringomyelia patients, who came to us under the diagnosis of multiple sclerosis. MRI also showed subcortical white matter lesions in 5 of 6 patients with syringomyelia. In summary, the diagnosis of multiple sclerosis should be reexamined when one of the following signs is present: (1) demonstration of Chiari malformation; (2) cerebrospinal fluid is normal; (3) visual-evoked potentials are normal. These signs may suggest syringomyelia even after years of primary progressive or relapsing remitting development of multiple neurological deficits and MRI visible white matter abnormalities.