Successful treatment of non-HIV progressive multifocal leukoencephalopathy: case report and literature review

Background Progressive multifocal leukoencephalopathy (PML) is a subacute onset demyelinating disease caused by JC virus and characterized by multifocal involvement of the subcortical white matter and cerebellar hemispheres or peduncles on magnetic resonance imaging (MRI). However, non-HIV PML patients with brain lesions limited to the cerebellum and brainstem have not been well characterized. Methods We report a 68-year-old man with systemic lupus erythematosus under treatment with immunosuppressants who developed non-HIV PML with brain lesions limited to the cerebellum and brainstem and successfully treated with a combination of mefloquine and mirtazapine. We performed a literature review to characterize patients with non-HIV PML with brain lesions limited to the cerebellum and brainstem. Results Eight cases with non-HIV brainstem/cerebellar form PML were identified including our case. All cases had compromised status related underlying diseases. Four (50%) had a good prognosis. Five cases were treated, including 3 with favourable outcomes. Between the good prognosis group (n = 4) and the poor prognosis group (n = 4), treatment status for PML and the interval between the initial manifestation and diagnosis did not differ. Among those who performed contrast-enhanced brain imaging, lesion enhancement was related to good prognosis (good prognosis group vs. poor prognosis group; 100% vs. 0%). Conclusion PML should be considered in the differential diagnosis of brain lesions limited to the cerebellum and brainstem in immunocompromised patients. The presence of immune response against JC virus and inflammatory reactions may indicate good prognosis in non-HIV brainstem/cerebellar form PML