Neuropsychiatric symptoms predict which patients with mild cognitive impairment develop Alzheimer disease

As the years add up, it's common to notice slight changes in our ability to remember and think. Older people who have more marked changes than their peers can be diagnosed with mild cognitive impairment. Currently, we can’t easily predict which of these patients will develop Alzheimer disease and which will not.

“It's hard to predict which patients will have a more rapid progression and receive a diagnosis of dementia,” said Maria Vittoria Spampinato MD, division director of Neuroradiology at the Medical University of South Carolina.

“It’s important to know who is likely to progress to dementia, as they will need a lot of support and assistance from their family and other caregivers,” she continued.

To improve our ability to predict progression to Alzheimer disease, Spampinato and her team looked at the connection between neuropsychiatric symptoms (NPS), such as worsened anxiety and depression, and the journey from mild cognitive impairment to dementia, specifically Alzheimer disease. Their findings, recently reported in the Journal of Alzheimer’s Disease, show that NPS is a useful model for predicting progression to Alzheimer disease.

Alzheimer's disease can be described as a glitch in the brain's communication system. The brain “glitches” because certain proteins clump abnormally, disrupting brain function. The two main types of clumping proteins are beta-amyloid plaques and tau tangles. These proteins can disrupt brain function by forming between or within neurons, leading to memory loss, problem-solving issues and, ultimately, difficulty completing daily tasks.

Spampinato and her team hoped to find out if NPS could be a simple and noninvasive method for tracking disease progression.

“Although it’s important to do lab testing to measure the number of amyloid plaques and tau disease, NPS testing is important in identifying which patients are at greater risk,” she said.

To test whether NPS could help to predict mild cognitive impairment to Alzheimer disease progression, the MUSC team identified 300 patients with mild cognitive impairment ages 65 and older from the Alzheimer’s Disease Neuroimaging Initiative database. Patients were given the Neuropsychiatric Inventory (NPI) to document symptoms, such as anxiety, depression, delusions, hallucinations, abnormal movement behavior and sleep disorders — collectively known as NPS — as potential early signs of preclinical Alzheimer disease to establish a prediction model for Alzheimer disease.

The study findings showed that more than a quarter of the patients with mild cognitive impairment went on to develop Alzheimer disease. For each one-point increase in NPI score, there was a 3% increase in the risk of mental decline leading to the diagnosis of Alzheimer disease.

Surprisingly, the study showed that NPS predicted the risk of mental decline better than certain established risk factors of Alzheimer disease.

Based on these findings, Spampinato recommends that patients with mild cognitive impairment be screened for NPS, as it is an important factor to consider for predicting disease progression.

“If you feel down or anxious and you experience memory issues as you age, it is important to seek help early and get a thorough evaluation for both cognitive and mental health concerns,” said Spampinato.

The prediction model developed by Spampinato and her team shows promise for identifying which patients with mild cognitive impairment will progress to Alzheimer disease. However, it will need validating in a larger group of patients recruited from memory care institutions before being used in the clinic.

The study’s findings emphasize the importance of considering NPS in the early diagnosis and treatment of preclinical Alzheimer disease. They also set the stage for future research aimed at unraveling the mechanisms underlying the progression from mild cognitive impairment to Alzheimer disease.

Source: News Release
Medical University of South Carolina
February 26, 2024