Spinal Taps May Help Diagnose Alzheimer's in Living Patients
People with mild memory loss may one day be able to use information gleaned from a spinal tap to determine if they are in the early stages of Alzheimer’s disease, researchers said.
Using computer modeling and previous findings, researchers from Ghent University in Ghent, Belgium, crafted a profile of what they expected the spinal fluid of people with Alzheimer’s to look like. In an analysis of more than 400 people with everything from a healthy memory to full-blown dementia, the scientists found that about 90 of the 102 patients deemed to have Alzheimer’s had an identical signature.
The findings, released yesterday in the Archives of Neurology, suggest doctors may be able to peer into the slow and uneven progress of Alzheimer’s, which researchers believe starts to develop a decade or more before symptoms appear. Currently, Alzheimer’s disease can be diagnosed only during an autopsy.
“To date, cerebrospinal fluid analyses have not been a routine component of assessment and care for patients with cognitive impairments and suspected Alzheimer’s disease in the U.S.,” wrote Zara Herskovits, a pathologist from Brigham & Women’s Hospital in Boston, and John Growdon, a neurologist from Massachusetts General Hospital in Boston, in an editorial published along with the study. “There is now ample evidence that these measurements have value.”
Pinpointing the amount of beta amyloid and tau in a person’s spinal fluid provides insights into the health of their brains, where the two proteins begin to aggregate in Alzheimer’s patients, according to the researchers.
The study was led by Geert De Meyer, from the department of applied mathematics and computer science at Ghent University.
Doctors and patients must be careful with the information, the researchers said. Almost three of four patients with mild memory loss had the same signature, as did one-third of those with no signs of memory loss. It was unclear if those patients were likely to develop Alzheimer’s.
There’s little doctors can now offer to patients who are at risk of Alzheimer’s. Existing medications ease symptoms of the disease for about six months, while there is nothing to avert or slow the onset or worsening of symptoms such as memory loss.
“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 identify clinically healthy individuals at risk for mild cognitive impairment and Alzheimer’s disease,” Herskovits and Growdon wrote.