Last modified: 2018-09-09
Abstract
Introduction: Mumps is a common childhood viral disease characterized by fever and swelling of the parotid gland. The prognosis is generally good, although some complications, such as encephalitis (0.1%), exist. Acute encephalopathy with biphasic seizures and late reduced diffusion is the most common type of acute encephalitis/encephalopathy. However, this type of encephalopathy has not been reported in association with mumps infection.
Case Description: A previously healthy 3-year-old Japanese boy had convulsions, conscious disturbance, and parotitis after fever for several days. Increased serum amylase level and presence of anti-mumps immunoglobulin M antibody confirmed mumps parotitis. The patient’s clinical course, cerebrospinal fluid examination results, and brain magnetic resonance images were consistent with acute encephalopathy with biphasic seizures and late reduced diffusion.
Discussion: In Japan, the mumps vaccine is not administered as a part of routine immunizations. It thus has low coverage (30-40%), and as a result, mumps infections are still common. In spite of each commonness, this is the first case of mumps-related acute encephalopathy with biphasic seizures and late reduced diffusion. This case may be representative of only a minority of patients with mumps-associated encephalitis/encephalopathy. Nevertheless, one should consider this diagnostic possibility. In order to prevent mumps-related complications, routine mumps vaccination should be considered.