Spinal-fluid test may help predict Alzheimers

Reseachers report that a spinal fluid test can be 100 per cent accurate in identifying patients with significant memory loss who are on their way to developing Alzheimers disease....

Reseachers report that a spinal fluid test can be 100 per cent accurate in identifying patients with significant memory loss who are on their way to developing Alzheimers disease. The study,which will appear Tuesday in the Archives of Neurology is one of a number of remarkable recent findings about Alzheimers.

Alzheimers,medical experts now agree,starts a decade or more before people have symptoms. And by the time there are symptoms,it may be too late to save the brain. Researchers are now finding accurate ways to detect Alzheimers long before there are symptoms. In addition to spinal fluid tests they also have new PET scans of the brain that show telltale amyloid plaques that are a feature of the disease. And they are testing hundreds of new drugs that might treat relentless brain cell death.

This is what everyone is looking for,the bulls-eye of perfect predictive accuracy, Dr Steven DeKosky,dean of the University of Virginia medical school said about the spinal tap study. Dr John Morris,a professor of neurology at Washington University,said the new study establishes that there is a signature of Alzheimers and that it means something. It is very powerful.

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The new study included more than 300 patients in their 70s,114 with normal memories,200 with memory problems and 102 with Alzheimers disease. Their spinal fluid was analysed for amyloid beta and for tau,a protein that accumulates in dead and dying nerve cells in the brain. Nearly every person with Alzheimers had the characteristic spinal fluid protein levels. Nearly three quarters of people with mild cognitive impairment,a memory impediment that can precede Alzheimers,had Alzheimers-like spinal fluid proteins. And every one of those patients with the proteins developed Alzheimers within five years. And about a third of people with normal memories had spinal fluid indicating Alzheimers. Researchers suspect that those people will develop memory problems.

The field is moving fast. You can get a test that is approved by the FDA,and cutting edge doctors will use it,Dr DeKosky said in favour of the test. But,said Dr John Trojanowski,a University of Pennsylvania researcher and senior author of the paper,given that people can get the test now,How early do you want to label people?

The prevailing hypothesis about Alzheimers says that amyloid and tau accumulation are necessary for the disease and that stopping the proteins could stop the disease.