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New Test May Detect Early Alzheimer’s Disease
By Allison Gandey, MedScape Today
June 15, 2009
Researchers have developed a new cognitive test that is quick to use, examines 10 skills, and reportedly detects 93% of cases of Alzheimer's disease. Published online June 10 in BMJ, investigators suggest the new self-administered test is a powerful and valid screening tool.
"If a patient completes the test while in the waiting area supervised by the receptionist, it can be scored and analyzed by the doctor in 2 minutes," explain the researchers, led by Jeremy Brown, MD, from Addenbrooke's Hospital, in Cambridge, the United Kingdom. "If there is time during the consultation to observe the patients filling in the test, this can also be a useful aid to diagnosis."
Dr. Brown is a neurologist, but his team found that with 10 minutes' training and a scoring sheet, a nurse without experience working in memory clinics was able to evaluate the test as accurately as a
specialist.
In an accompanying editorial, Claire Nicholl, MD, also at Addenbrooke’s Hospital, pointed out that the study showed that the new test was more sensitive than the Mini-Mental State Examination in this patient population (93% vs 52%).
More Sensitive Than Mini-Mental State Examination
"Longer scales are used in specialist settings," Dr. Nicholl notes, "but the test is not designed to replace these."
In this cross-sectional study, investigators evaluated subjects from 3 hospitals including a memory clinic. They looked at 540 control participants and 139 patients with dementia or amnesic mild cognitive impairment.
In the diagnosis of early Alzheimer's disease with a cut-off point of <42/50, the test had good sensitivity (93%), specificity (86%), and interrater reliability.
The test requires participants to write 10 answers on a double-sided card. The requested tasks evaluate a range of areas, including the patient's semantic knowledge, ability to calculate and name objects, and recall.
"If the memory test is to be adopted more widely, it must be validated in a range of settings and different populations," Dr. Nicholl writes. "Until then, the most important message is that clinicians should identify a test that suits their clinical setting, use it to screen or case find as appropriate, and develop experience in its use to improve the identification of patients with early dementia."
Must Be Validated
Dr. Nicholl points out that the authors do not comment on the ethnicity of the study participants, but the local population is mainly white and some of the items on the test likely show some cultural bias.
Elizabeth Gould, director of quality care programs at the Alzheimer's Association, echoed similar concerns to Medscape Neurology. Speaking during a recent interview, she emphasized the importance of taking cultural differences into account as much as possible. She also stressed the importance of early detection.
A Web site is being developed for clinicians to download the new test, scoring sheets, and further instructions. It will be available at www.tymtest.com.
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