A new test could detect Alzheimer’s disease at least ten years before symptoms appear – paving the way for early treatment.

The discovery of a fall in levels of a certain type of genetic material could signal an increased risk of developing Alzheimer’s.

The biological marker is found in cerebral spinal fluid (CSF) at least 10 years before signs of dementia become apparent.

Currently, the only way to accurately diagnose the disease is by post-mortem neuropathological analysis, although memory and other brain function tests are used to determine whether drugs and other treatment may help.

Spanish researchers at the CSIC Institute of Biomedical Research of Barcelona believe they may have found a marker that could suggest the disease process is underway before symptoms start to show.

A new test could detect Alzheimer’s disease at least ten years before symptoms appear

They found a drop in the content of mitochondrial DNA (mtDNA) – genetic material present in the energy centre of cells – in spinal fluid may be a signal for the disease.

They suggest that decreased mtDNA levels reflect the diminishing ability of mitochondria to power brain cells, thus triggering their death.

The drop in the concentration of mtDNA precedes the appearance of other recognized biochemical Alzheimer’s biomarkers, suggesting the process of Alzheimer’s disease starts earlier than previously thought and that mtDNA depletion may be one of the earliest predictors.

Researchers have previously been unable to detect the genetic material in spinal fluid, but they used a new technique to amplify tiny amounts, says a study in the journal Annals of Neurology.

The researchers hope other labs and hospitals will be able to replicate the results.

The researchers say by finding a way to block the degeneration, clinicians may be able to diagnose and treat the disease before symptoms even appear.

Lead author Dr. Ramon Trullas said: “If our initial findings can be replicated by other laboratories, the results will change the way we currently think about the causes of Alzheimer’s.”

“This discovery may enable us to search for more effective treatments that can be administered during the pre-clinical stage.”