Spinal fluid test provides Alzheimer's diagnosis

Scientists have taken a step towards developing an early screening test for Alzheimer's disease.

Researchers in the US have discovered the presence of "biomarkers" in the cerebrospinal fluid – which surrounds the spinal cord – enabling them to predict with 90 per cent accuracy the presence of the disease.

Tests showed that a "signature" consisting of three biomarkers present in the fluid of 90 per cent of patients with Alzheimer's disease was also found in more than a third of "normal" older adults, who showed no sign of mental deterioration. The finding suggests these adults were in the earliest stages of the disease, before clinical symptoms had appeared. In the future, if medicines are developed which can effectively slow its development, the test might be used to select patients for preventive treatment.

The findings are published in the journal Archives of Neurology. An editorial said there was now "ample evidence" that analyses of the cerebrospinal fluid had "value".

"Gazing into the future when there are neuroprotective medications for Alzheimer's disease, we can envision a recommendation that cerebrospinal fluid analyses be implemented as a screening test to... enable early application of treatments to delay onset of symptoms," it says.