[Laboratory diagnosis of multiple sclerosis].

In 26 patients with multiple sclerosis 100% responded abnormally to magnetic resonance imaging of the brain. Lesions in the posterior fossa were observed in 18 patients. The auditory brain stem response was abnormal in 15 patients, and 22 had abnormal immunoglobulins in the cerebrospinal fluid. The correlation between abnormalities of the auditory brain stem response and the magnetic resonance images was greatest in a subgroup where the two investigations were performed within a ten day interval. Results from magnetic resonance imaging, evoked potentials and cerebrospinal fluid investigations were used to reclassify 13 of 15 patients with clinically "possible" or "probable" multiple sclerosis to a higher level using Poser's criteria. Evoked potentials (the auditory brain stem response in particular) correlated best with clinical multiple sclerosis category. We recommend that magnetic resonance imaging is established as a first-hand investigation in evaluations of multiple sclerosis. Evoked potentials and cerebrospinal fluid investigations may prove to be more specific, however, and these investigations should also be performed as a routine.