Epidemiology and prognosis of acute myelitis in Southern Finland

In this study we analyzed all acute adult (>15 years) myelitis cases in the province of Uusimaa in Southern Finland during the years 1981-1993. Only cases with acute infectious myelitis were included. Demyelinating diseases, and medullopaties due to degeneration, traumatic, toxic, hereditary, nutritional or metabolic causes were excluded. A total of 45 patients fulfilled the criteria. The mean incidence was 3.5 cases/million inhabitants/year. The mean latency time from the initial infection to the beginning of neurological symptoms was 11 days. Motor paraparesis was found in 62% and tetraparesis in 13%. Sensory symptoms were found in 82% and bowel disturbances were experienced by 71% of patients. Normal cerebrospinal fluid (CSF) leukocytes were seen in 18% of patients, and CSF protein was elevated in 70% of patients. Case fatality was 6.7%. Permanent care in hospital needed by 13% of patients, and after 24 months 88% were ambulatory. Prognosis is quite good in myelitis, and normal CSF leukocytes do not exclude myelitis.