New Test Predicts Alzheimer’s Dementia Years Before Onset of Symptoms

Alzheimer’s dementia is a chronic and debilitating disease that slowly robs patients of their memory and cognitive acumen and eventually causes inability to care for oneself. It is the most common form of dementia. This incurable and terminal illness was first described by Dr. Alois Alzheimer, a German psychiatrist, in 1906. Since the first description, there has been little progress made in developing effective treatments for the disease. Most medications only mask the symptoms and do little to reverse the progression of the disease. There are approximately 26 million people worldwide who suffer with this disease, and it is estimated that 1 in 85 people are afflicted with the illness. Early diagnosis of the disease is crucial, and may eventually help in the treatment of this form of dementia. Researchers lead by Dr. Robert Perneczky, from the Technical University in Munich, Germany, have described a early diagnostic test that can identify patients who will go on to develop Alzheimer’s dementia. The study was published in the June 22 issue of Neurology. The researchers studied a cohort of 58 patients with mild cognitive impairment and analyzed cerebrospinal fluid from the participants. After 3 years of follow up, 21 participants had progressed to develop probable Alzheimer’s dementia, 27 still had mild cognitive impairment, and 8 had reverted to normal cognition. There were 2 participants that developed frontotemporal dementia and they were excluded from the analysis. The cerebrospinal fluid from the participants was analyzed for several proteins that have been associated with Alzheimer’s dementia. These included soluble amyloid precursor proteins (alpha and beta), tau, and amyloid beta 42. The researchers found that the participants that progressed from mild cognitive impairment to Alzheimer’s dementia had significantly higher levels of soluble amyloid precursor protein beta in their cerebrospinal fluid as compared to the other groups. Combining soluble amyloid precursor protein beta, tau, and age was able to differentiate the group that progressed to Alzheimer’s dementia with a sensitivity of 80% and a specificity of 81%. The researchers concluded that, “These findings suggest that [soluble amyloid precursor protein beta] may be clinically useful, and superior to [amyloid beta 42], in the early and differential diagnosis of incipient [Alzheimer’s dementia]”. These findings will have to be confirmed on a larger scale but they could become clinically useful in the early diagnosis of patients that could eventually develop Alzheimer’s dementia. This may lead to earlier treatment and possibly delay the onset of memory deficits.

Reference:

R. Perneczky et al. “CSF soluble amyloid precursor proteins in the diagnosis of incipient Alzheimer disease” Neurology. 2011; 77:35-38.