Millions With Undiagnosed Cognitive Decline

Millions with undiagnosed cognitive decline

A recent study indicates that more than 90% of individuals with mild cognitive impairment may not be aware of their condition, even though it could be an early indication of Alzheimer's disease.

In this research, scientists analyzed data from over 40 million individuals aged 65 and above who were covered by Medicare, the U.S. healthcare program. The findings revealed that only approximately 8% of the expected eight million cases of mild cognitive impairment (MCI) were documented in these health records. The remaining 7.4 million cases were left undiagnosed, as reported in The Journal of Prevention of Alzheimer's Disease.

"We initially anticipated that MCI would be underdiagnosed, but the extent of underdiagnosis has exceeded our expectations," noted Dr. Soeren Mattke, the lead author of the study.

Dr. Mattke, who serves as a professor and directs the Center for Improving Chronic Illness Care at the University of Southern California in Los Angeles, suggests that this underdiagnosis may be attributed to the relatively mild nature of symptoms, such as misplacing car keys or forgetting appointments, which are often dismissed as normal signs of aging. Additionally, many healthcare professionals may not prioritize the diagnosis of MCI.

Remarkably, a separate study involving 200,000 Medicare enrollees aged 65 and older who were treated at over 54,000 primary care clinics revealed that a staggering 99 percent of doctors underdiagnosed MCI. This study, coauthored by Dr. Mattke, also found that only 8 percent of MCI cases receive accurate diagnoses.

Diagnosing mild cognitive impairment (MCI) can be time-consuming, and many clinicians lack the resources to do so. Moreover, there is a widespread belief that diagnosing MCI is inconsequential. However, with the recent approval of new treatments for Alzheimer's disease, which accounts for approximately 50% of MCI cases, there is now a heightened sense of urgency to identify patients who may benefit from these therapies.

Two new drugs, lecanemab and donanemab, have been shown in clinical trials to slow the progression of Alzheimer's disease. These newer drugs work by reducing the accumulation of amyloid-beta proteins in the brain. Amyloid-beta proteins are thought to play a role in cognitive impairment. However, these drugs carry a risk of serious side effects, including brain bleeding and swelling.

Lecanemab (Leqembi) received provisional approval from the FDA in January and full approval in July. Eli Lilly expects the FDA to decide on donanemab by the end of the year. Aducanumab (Aduhelm), another drug that targets amyloid, was approved by the FDA in 2021 as an Alzheimer's treatment, despite concerns about its effectiveness.

Early diagnosis of mild cognitive impairment (MCI) can help people take steps to improve brain function, but there are concerns about the need to treat MCI patients with newer anti-amyloid drugs for Alzheimer's disease, says Dr. Majid Fotuhi, an adjunct professor and neurologist at George Washington University in Washington, DC, who was not involved in the new studies.

It is important for physicians to address cognitive decline in the elderly and help them identify the potential causes, but they should not rush to tell their patients they are one step away from developing Alzheimer's disease and need to take anti-amyloid medications,