Downbeat Nystagmus as a Presenting Manifestation of Neurolisteriosis in a Pregnant Woman.

Listeria monocytogenes has tropism towards two immunologically "privileged" sites, the fetoplacental unit in pregnant women and the central nervous system (neurolisteriosis) in immunocompromised individuals. We report a case of neurolisteriosis in a previously asymptomatic pregnant woman from rural West Bengal, India, who presented with a subacute onset febrile illness with features of rhombencephalitis and a predominantly midline-cerebellopathy (slow and dysmetric saccades, florid downbeat nystagmus, horizontal nystagmus, and ataxia). With timely detection and the institution of prolonged intravenous antibiotic therapy, both the mother and the fetus were saved uneventfully.