May 16, 2011 -- More than one-third of people who develop early-onset Alzheimer’s disease may experience initial symptoms such as behavior, language, or vision problems rather than memory loss, a new study shows.
Researchers in Spain say more than half of people who develop Alzheimer’s before age 60 are initially misdiagnosed because they exhibit problems other than the memory loss that doctors normally check for.
The scientists reviewed the cases of 40 people whose brains -- studied after autopsy -- showed they had Alzheimer’s disease. The people ranged in age from 46 to 60.
The researchers also reviewed information about the age when the symptoms began, as well as family history of those whose brains indicated they had Alzheimer’s.
About 38% of the people with confirmed early-onset Alzheimer’s showed symptoms other than memory problems, researchers report.
These included a decline in the ability to carry out tasks, often referred to as executive function, or problems with behavior, vision, or language.
In the people with the unusual or atypical symptoms and no memory problems, 53% had been incorrectly diagnosed when first seen by a doctor. Only 4% of those with memory problems had been incorrectly diagnosed.
Of those with unusual initial symptoms, 47% were still incorrectly diagnosed at the time of their deaths. Four of the study participants with early-onset Alzheimer's had family histories of Alzheimer’s.
“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,” study researcher Albert Llado, MD, PhD, of the Hospital Clinic of Barcelona, says in a news release.
Avoiding Misdiagnosis of Alzheimer's
Llado says scientists need to look for biomarkers as indicators of Alzheimer’s disease so that misdiagnoses won’t happen so often.
There is a need for doctors to be able to more easily recognize and diagnose early-onset Alzheimer’s, which would allow them to do a better job of treating patients and improving the quality of their lives.
According to the Alzheimer’s Association, an estimated 5.4 million Americans of all ages have the disease in 2011. This includes 5.2 million aged 65 and older, and 200,000 who are younger.
One of the study researchers, J.L. Molinuevo, MD, PhD, disclosed receiving funds from pharmaceutical companies.
The study is published in the May 17 issue of Neurology, the medical journal of the American Academy of Neurology.