Opsoclonus in Hemophilus influenzae meningitis.

We studied a 3-month-old boy who had opsoclonus in association with acute bacterial meningitis. The CSF IgG and IgM were elevated acutely, gradually returning to normal with clinical improvement. Correspondingly, CSF cytomorphology showed excessive plasmocytosis and a higher proportion of reactive lymphocytes than expected in an acute bacterial meningitis. These abnormalities in CSF cytology are effects of an abnormal immune response in the CNS, and provide evidence to support an immunopathic basis to opsoclonus.