Study: Brain Volume and Alzheimer’s Disease

The following is a guest post by Dr. Gloria C. Chiang, M.D., UCSF Radiology Resident.

I recently co-authored a study, published in the June issue of Radiology, that found that brain volume may indicate pre-clinical Alzheimer’s. I thought I’d talk a little bit about this disease and what my research was trying to accomplish.

Alzheimer's disease is estimated to afflict over 5 million people in the U.S. and represents the sixth leading cause of death. Due to the enormous toll that Alzheimer's exacts on caregivers and society, there is great interest in identifying at-risk individuals early and, hopefully, slowing down the course of disease.

At the end of April 2011, workgroups from the National Institute of Aging and the Alzheimer's Association put forth new guidelines for diagnosing Alzheimer's disease. These guidelines recognize 3 stages of disease:

1.  Dementia -- patients in this stage suffer from the loss of mental functions (such as thinking, memory, and reasoning) that is severe enough to interfere with their daily functioning.

2.  Mild cognitive impairment due to Alzheimer's disease – in this stage, patients have memory difficulties, but are still able to perform activities of daily living.

3.  Preclinical Alzheimer's disease – patients in this stage have Alzheimer pathology, such as cerebral amyloid deposition or neurofibrillary tangles, but no clinical evidence of memory impairment. This stage promotes the concept that Alzheimer's disease begins many years before symptoms of dementia appear and represents a point at which imaging may play a role in identifying at-risk individuals.

In our study, we used regional brain volumes from a baseline MRI to differentiate cognitively normal individuals who progressed to memory decline over two years from those who did not. Our findings point to indicators that may help doctors identify cases of pre-clinical Alzheimer’s and, eventually, enable them to prevent the progression of the disease.