The use of cerebrospinal fluid and neuropathologic studies in neuropsychiatry practice and research.

The gold standard for diagnosis of neurodegenerative diseases (ie, Alzheimer disease, frontotemporal dementia, Parkinson disease, dementia with Lewy bodies, amyotrophic lateral sclerosis) is neuropathologic examination at autopsy. As such, laboratory studies play a central role in antemortem diagnosis of these conditions and their differentiation from the neuroinflammatory, infectious, toxic, and other nondegenerative etiologies (eg, rapidly progressive dementias) that are encountered in neuropsychiatric practice. This article summarizes the use of cerebrospinal fluid (CSF) laboratory studies in the diagnostic evaluation of dementia syndromes and emerging CSF biomarkers specific for underlying neuropathology in neurodegenerative disease research.