Experts in the UK say they might have found an early test for Alzheimer’s, the BBC reports, using a lumbar puncture test and a brainscan to pinpoint patients with early signs of dementia. One day, doctors could use this test to prescribe drugs to slow or stop the disease. There are many potential drugs that could work, but it’s hard for doctors to test how effective they are because dementia is usually only diagnosed once the disease is fairly advanced. To detect the most common form of dementia, which is Alzheimer’s, at its earliest stage might be possible, according to Dr. Jonathan Schott and colleagues at the Institute of Neurology, University College of London. They check for brain shrinkage and lower-than-normal levels of a protein called amyloid in fluid around the brain and spinal cord.