[Case of acute brainstem and striatal encephalopathy associated with Mycoplasma pneumoniae infection].

Acute encephalopathy with bilateral striatal necrosis (EBSN) is a rare reversible neurological disease characterized by an abrupt onset following an acute infectious disease and by severe extra-pyramidal signs associated with striatal lesions. Brainstem involvement is rarely observed in this disease. We report a 10-year-old boy who had EBSN associated with Mycoplasma pneumoniae. He became lethargic after acute bronchitis. A few days later, he showed extra-pyramidal signs, pyramidal signs and overactive urinary bladder symptoms. Cranial T2-weighted and diffusion-weighted magnetic resonance imaging (MRI) demonstrated high-signal intensity in the bilateral striatum and substantia nigra. These symptoms improved soon after the administration of L-dopa in the acute phase. The effects of corticosteroids were not apparent in the acute phase. The serum particle agglutination titers against Mycoplasma pneumoniae determined on admission, the 12th hospital day and 2 months later were 1:2,560, 1:2,560 and 1:320, respectively. Two years later, a mild tic was observed. A mild atrophy was noted in the bilateral basal ganglia, but not in the substantia nigra on cranial MRI. This case is the first reported one with EBSN with the presence of an overactive urinary bladder, which could possibly caused by loss of dopaminergic inhibition.