Lumbar Punctures are done to collect Cerebral Spinal Fluid, or CSF.  CSF is very important for researchers to look at and understand.  It is the fluid that surrounds the brain and is the only way of looking at brain chemicals in a living person.  In the ADNI study, researchers will be looking at the CSF in some volunteers, alongside the images of their brains and information collected about their health and cognitive status.  Not everyone who agrees to take part in ADNI needs to have CSF sampling.

A Lumbar Puncture (Spinal Tap) Test is a procedure to remove a small sample of cerebral spinal fluid from the lower spine. A very small needle is inserted between the vertebrae (backbones) in the lower back and into the space containing the spinal fluid, CSF.

The results will provide researchers with the most complete picture of the person.  It will also allow researchers to compare each of the three methods against each other and help decide which method presents the most accurate clinical picture of the person with Alzheimer's Disease, with MCI, or the person with no memory problems.