Acute cerebellar ataxia in pediatric legionellosis.

Acute-phase and convalescent-phase sera of 66 children, aged 3 months to 12 years, with neurologic disorders of unknown etiology were tested against Legionella pneumophila polyvalent and monovalent antigens (groups 1 to 4). Three significant antibody titer increases were obtained, all in children with acute cerebellar ataxia. This neurologic syndrome was characterized by sudden onset of muscle hypotonia and inability to sit or walk, with no other specific neurologic or systemic symptoms. Persisting pharyngitis always preceded ataxia. Fever of short duration was still present. Gastrointestinal disturbance occurred in two of the three children. Abnormal laboratory findings were, not always simultaneously, high ESR and leukocytosis with lymphocytosis. CSF levels and electromyographic findings were normal in two of the children. Two children received oral betamethasone. Recovery was complete within seven to ten days without antibiotic treatment. These studies indicate the possible etiologic role of L pneumophila in acute cerebellar ataxia.