Only one quarter of primary care patients with mild cognitive impairment have progression to dementia within three years
The concept of mild cognitive impairment has been introduced into the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition as mild neurocognitive disorder, making it a formal diagnosis.
As part of the German Study on Aging, Cognition and Dementia in Primary Care Patients, researchers investigate determinants of the future course of MCI in primary care patients to help primary care physicians counsel patients about prognosis. Analyzing three years of follow-up data on 357 primary care patients aged 75 years or older with a diagnosis of MCI without dementia, researchers found 42 percent had a remittent course (with remission of symptoms and normal cognitive function one and a half and three years later) 21 percent had a fluctuating course (with changing status between MCI and normal cognitive function), 15 percent had a stable course (with impairment at each assessment that neither worsens to dementia nor improves to normal cognitive function), and 22 percent had a progressive course (with the development of dementia).
They found patients were at higher risk of advancing from one course to the next along this spectrum if they had symptoms of depression, impairment in more than one cognitive domain, more severe cognitive impairment and were older. Specifically, they found patients' performance on tasks of learning new material (CERAD subtest word list memory and delayed recall and memory) and the Geriatric Depression Scale, which can detect depressive symptoms, helped predict a progressive versus a remittent course.
The authors point out that only about one quarter of patients with MCI progress to dementia within the next three years, which means three quarters of patients with MCI stay cognitively stable or even improve within three years. Patients, they conclude, should not be alarmed unnecessarily by receiving a diagnosis of mild neurocognitive disorder.
By Marion Eisele, PhD, University Medical Center, Hamburg, Germany Hanna Kaduszkiewicz, MD, Prof, Institute of Primary Medical Care, Kiel, Germany