People with Alzheimer's disease who were given brain scans and diagnosed early in the course of their illness did better than those who got a later diagnosis, a new study finds. They tended to get Alzheimer’s drugs earlier in the course of their disease, when these drugs may be most effective. Over the next two years, they performed better on memory and thinking tests.
The findings come from scientists at the University of California, Los Angeles, who monitored patients who were part of the ongoing Metabolic Cerebral Imaging in Incipient Dementia study, sponsored by the government’s Centers for Medicare and Medicaid Services. The results were presented at the Medical Biotech Forum in China in September.
The study looked at 63 men and women who were given PET scans using a radioactive dye called FDG that highlights areas of the brain affected by Alzheimer’s. Only some of the patient’s doctors were told the results of the brain scans at the start of the study.
"During the subsequent two years after their PET scans, these patients had superior executive function, better memory abilities and greater preservation of overall cognitive function,” said Dr. Daniel Silverman, the lead author of the study. It’s the first study to provide “direct evidence” that patients whose early Alzheimer's disease is revealed by imaging tests will fare better than those not given such tests, he said.
One reason why patients whose results were known sooner tended to do better may have been because their doctors were more likely to prescribe medications. About 40 percent of the patients whose doctors were informed of the brain problems were given drugs specifically indicated for dementia within the first six months of the study. In contrast, none of the patients whose brain scan results remained unknown were prescribed Alzheimer’s medications in the first six months, and only 12 percent were prescribed those medications by the end of the first year.
The findings suggest that early brain scans may improve outcomes in people with early Alzheimer’s. The researchers estimated that patients with undiagnosed Alzheimer’s may need to enter nursing home care six to nine months earlier than someone who was diagnosed and treated sooner in the course of their disease.
So far, Medicare has not reimbursed patients with suspected early Alzheimer’s to get PET scans. Only after symptoms of dementia have set in, and the brain damage is fairly extensive, will Medicare pay for such scans. At that point, medications are less likely to offer any benefit.