CLINICOPATHOLOGICAL STUDY OF PARANEOPLASTIC BRAIN-STEM ENCEPHALITIS AND OPHTHALMOPARESIS

We report three patients who exhibited ophthalmoparesis as an early ma nifestation of progressive paraneoplastic brainstem encephalitis. In t wo patients, anti-Hu antibodies were detected, whereas in a third, fou nd at postmortem to have thyroid cancer, no antibodies were identified . Postmortem examination of two patients disclosed extensive gliosis, perivascular inflammation, and cell loss in the midbrain and pontine t egmentum. In one of these patients, there was selective neuronal loss within the third, fourth, and sixth nerve nuclei. We conclude that sup ranuclear or nuclear ophthalmoparesis may be the initial manifestation of paraneoplastic brainstem encephalitis. Our pathologic data suggest that the ophthalmoparesis may result from selective neuronal death wi thin the brainstem tegmentum and ocular motor nuclei.