Rapidly progressive dementia with hypoglycorrhachia.

We report a woman who presented with rapidly progressive dementia and hypoglycorrhachia and discuss the approach and differential diagnosis for her condition. Rapidly progressive dementia poses a variety of challenges to the treating clinician, not only due to the speed of disease progression, but also due to the poor prognosis if intervention is delayed. The differential diagnosis of a patient presenting with rapid cognitive and functional decline is broad and includes degenerative, infectious, toxic, and neoplastic etiologies, some of which can be identified clinically through history and physical examination. Diagnostic evaluation using gadolinium-enhanced MRI, electroencephalography, and serum and cerebrospinal fluid testing is often required. The utility of testing for cerebrospinal fluid 14-3-3 antigen and tau is also reviewed.