MUMPS VIRUS INFECTION SIMULATING PARALYTIC POLIOMYELITIS

Abstract

Eleven cases clinically considered to be mild paralytic poliomyelitis are reported in which there was clearcut serologic evidence of mumps virus infection. Poliomyelitis viruses were not isolated from the stools and complement-fixing and neutralizing antibodies to poliomyelitis were either absent (4 cases) or did not significantly change in titer between the acute- and convalescent-phase specimens of serum. Clinically, fever, headache, vomiting, nuchal rigidity, stiff back, muscle pain and slight to moderate weakness of several muscle groups were prominent manifestations. The cerebrospinal fluid uniformly contained over 100 leukocytes and commonly over 300, predominantly lymphocytes. Only 2 of the 11 cases developed evidence of parotitis, and in these, parotitis did not antecede the central nervous system manifestations. Electroencephalograms were abnormal in 3 of 8 cases. All 11 cases had evident muscle weakness at the end of the acute phase of illness, and four had slight residual weakness on convalescent examination 2 to 5 months after onset. There was no significant predilection for any muscle group. These observations emphasize that central nervous system involvement with the virus of mumps may be manifested as a syndrome of meningomyelitis and be erroneously diagnosed as paralytic poliomyelitis. Weakness is usually highly transitory but residual involvement may persist for some months. As the incidence of paralytic poliomyelitis is reduced by widespread immunization mumps virus may assume increasing relative importance as a cause of "poliomyelitis-like" disease.