rapidly progressive ataxia ddx

in immunocompentent patients:

stroke,
multiple sclerosis
sarcoidosis,
primary or metastatic diseases,
paraneoplastic disorders,
toxins/drugs (lead, anticonvulsants, salicyclates, aminoglycosides, sedatives, fluorouuacil, cytarabine),
Miller Fisher syndrome,
infection (HIV, viral/postviral cerebellitis, Creutzfeld Jacob disease, progressive multifocal leukoencephalopathy),
alcoholic cerebellar degeneration, thiamine deficiency,
autoimmune ( SLE, Sjogrens, Hashimoto's disease, cerebellar ataxia with anti GAD or antigliadin antibodies).