Early stages of Alzheimer’s difficult to detect: Study

By Dr. Ananya Mandal, MDMay 17 2011

According to a new study, more than half of people who develop Alzheimer's disease before the age of 60 are initially misdiagnosed as having other kinds of brain disease when they do not have memory problems. The research is published in the May 17, 2011, print issue of Neurology, the medical journal of the American Academy of Neurology.

For this research the team reviewed the cases of 40 people from the Neurological Tissue Bank-University of Barcelona-Hospital Clínic-IDIBAPS, Barcelona, Spain, whose brains showed that they had Alzheimer's disease in an autopsy. Researchers also reviewed information about the age at which the symptoms began and family history.

They found that about 38 percent experienced initial symptoms other than memory problems. This study went on the reveal that one-third of people with confirmed early onset Alzheimer's disease showed symptoms other than memory problems, such as behavior, vision or language problems and a decline in executive function, or the ability to carry out tasks. In people with atypical symptoms and no memory problems, 53 percent were incorrectly diagnosed when first seen by a doctor, compared to four percent of those who had memory problems. They were mainly diagnosed with other types of dementia. Of those with unusual initial symptoms, 47 percent were still incorrectly diagnosed at the time of their death.

“[Alzheimer's disease] is a common cause of early-onset dementia and should always be considered as an alternative diagnosis,” the authors write. 

Study author Albert Lladó, MD, PhD, with the Alzheimer's Disease and Other Cognitive Disorders Unit, Hospital Clínic of Barcelona and the Institute of Biomedical Investigation August Pi i Sunyer (IDIBAPS), in Barcelona, Spain said, “People who develop early onset Alzheimer's disease often experience these atypical symptoms rather than memory problems, which can make getting an accurate diagnosis difficult… Biomarkers of Alzheimer's disease and other disorders are needed for us to better recognize, diagnose and treat early onset Alzheimer's disease sooner to improve the quality of life of these patients.”

The study was supported by a grant from the Hospital Clínic-Emili Letang

Alzheimer’s is a progressive brain disease that slowly causes problems with memory, thinking skills and behavior. Symptoms usually develop at a slow pace and get worse over time. There’s approximately 5.4 million Americans living with Alzheimer’s, and out those patients, only about 5 percent have early onset Alzheimer’s, which develops before the age of 65.

Dr. Stephen Rao, who did not take part in the study, works with Alzheimer’s patients at the Cleveland Clinic in Ohio. “The initial symptoms may actually not be memory problems, but they can be difficulties with personality change or they can be in other cognitive domains, such as language, visual or spatial processes,” Rao said. “Diagnosing Alzheimer’s disease can be very challenging and that’s one of the reasons why much of research today is looking for various biomarkers to diagnose the disease prior to the current gold standard, which is the autopsy,” Rao concluded.