Correlation of rCBF (SPECT), CSF tau, and cognitive function in patients with dementia of the Alzheimer's type, other types of dementia, and control subjects.

Background: The diagnosis of Alzheimer's disease (AD) during life remains difficult and a definite diagnosis of AD relies on histopathological confirmation at post-mortem or by cerebral biopsy. It is well known that levels of tau proteins are consistently and significantly increased in the cerebrospinal fluid (CSF) of Alzheimer's patients versus levels in normal controls. However, the sole use of this biochemical marker as a test for AD is hampered by mediocre specificity, since tau concentrations may also be elevated in certain other neurological disorders (OND).