Indications of Alzheimer's disease may be evident decades before first signs of cognitive impairment

(Press-News.org) Researchers at Mount Sinai School of Medicine have found that patients with Alzheimer's disease have lower glucose utilization in the brain than those with normal cognitive function, and that those decreased levels may be detectable approximately 20 years prior to the first symptoms of Alzheimer's disease. This new finding could lead to the development of novel therapies to prevent the eventual onset of Alzheimer's. The study is published online in the journal Translational Neuroscience.

Using mice modified to develop Alzheimer's disease, the research team found that when β-amyloid, an abnormal protein linked to Alzheimer's disease, starts to become detectable in the brain in its soluble toxic form, the mitochondria, or "power plants" of the cell where glucose is converted into energy, became impaired. Within the equivalent of about 20 human years, mice with decreased energy metabolism developed signs of Alzheimer's disease such as cognitive defects and impairment of the synaptic terminal, the area of brain cells important in memory formation.

"This evidence in mice validates that the diagnosis of probable Alzheimer's disease may be the end result of impairment in brain cell energy production," said the study's lead author, Giulio M. Pasinetti, MD, PhD, The Saunder Family Professor in Neurology, and Professor of Psychiatry, Geriatrics, and Adult Development at Mount Sinai School of Medicine. "Identifying that mitochondrial impairment is evident years earlier than cognitive defects is a major breakthrough."

"This new evidence could revolutionize the way we design interventions," said Merina T. Varghese, MD, co-author of the study and Postdoctoral Fellow in Neurology at Mount Sinai School of Medicine. "This study sets the stage for the development of potential novel preventions or therapies to apply in humans, even when they have normal cognitive function, to prevent the eventual onset of Alzheimer's disease."

### About The Mount Sinai Medical Center

The Mount Sinai Medical Center encompasses both The Mount Sinai Hospital and Mount Sinai School of Medicine. Established in 1968, Mount Sinai School of Medicine is one of few medical schools embedded in a hospital in the United States. It has more than 3,400 faculty in 32 departments and 15 institutes, and ranks among the top 20 medical schools both in National Institute of Health funding and by U.S. News & World Report. The school received the 2009 Spencer Foreman Award for Outstanding Community Service from the Association of American Medical Colleges.

The Mount Sinai Hospital, founded in 1852, is a 1,171-bed tertiary- and quaternary-care teaching facility and one of the nation's oldest, largest and most-respected voluntary hospitals. U.S. News & World Report consistently ranks The Mount Sinai Hospital among the nation's best hospitals based on reputation, patient safety, and other patient-care factors. Nearly 60,000 people were treated at Mount Sinai as inpatients last year, and approximately 530,000 outpatient visits took place.