An unusual cause of cerebellar ataxia in an immunocompromised elderly patient

Background Parvovirus B19 is a single-stranded DNA virus belonging to the family Parvoviridae, genus Erythrovirus. PVB19 infection is most common in the pediatric population, manifesting as erythema infectiosum. In patients with hemoglobinopathy, PVB19 infection is known to cause aplastic anemia. PVB19 infection rarely affects the nervous system - reported manifestations include seizures, encephalitis and meningoencephalitis. Less common presentations include stroke, cerebellar ataxia, optic neuritis, brachial plexitis, Guillain-Barré syndrome and carpal tunnel syndrome. Methods Review the different central nervous system (CNS) manifestations and treatment strategies in all reported cases of adult CNS PVB19 infection. Results Cerebellar ataxia is a very rare manifestation of PVB19 CNS infection. Our patient had refractory chronic lymphocytic leukemia and PVB19 in bone marrow and serum; he presented with 6-week history of progressive pan-cerebellar ataxia. CSF was acellular but PVB19 was present on PCR test. Early treatment with intravenous immunoglobulin (IVIG) led to improvement in the patient's neurological deficits. Conclusions PVB19 CNS infection should be in the differential as a cause of cerebellar ataxia in immunocompromised patients. Recognition is critical to early institution of appropriate therapy. Our patient showed considerable improvement in ataxia after IVIG therapy.