Primary care physicians (PCPs) provide the majority of dementia care. However, many PCPs feel insufficiently trained to diagnose dementia, lack time to incorporate dementia screening, and are concerned about sensitively sharing a diagnosis of dementia.1 Timely diagnosis of dementia is important. Benefits of timely diagnosis include decreased caregiver stress and delayed transition to long-term care. This article reviews the definitions and diagnostic criteria of mild cognitive impairment (MCI) and dementia, describes available screening tests for MCI and dementia, and discusses how to sensitively share a diagnosis of dementia.
Definitions and Diagnostic Criteria
MCI and dementia exist on a spectrum where MCI is an intermediary condition between normal cognition and dementia. Estimates suggest that each year 8-13% of persons with MCI will progress to dementia, while up to 16% will revert to normal cognition and others will remain with MCI.2, 3
The Diagnostic and Statistical Manual 5th edition (DSM-5) refers to dementia as a major neurocognitive disorder and MCI as a minor neurocognitive disorder and provides diagnostic criteria for dementia and MCI.3 Per the DSM-5, to make a diagnosis of MCI, the patient must have a decline in cognitive functioning that does not interfere with function in daily activities and is not explained by delirium or a psychiatric disorder. MCI should be detected by a history gathering from the patient and a second informant (e.g., a caregiver) and by cognitive testing. A patient needs to have deficits in only one of the six following cognitive domains to meet criteria for MCI: complex attention (e.g., ability to tap each time letter “A” is said), executive function (e.g., planning, organization), learning and memory (e.g., short-term recall), language (e.g., aphasia), perceptual-motor (e.g., visuospatial or navigation skills), or social cognition (e.g., identification of emotions in others).
To make a diagnosis of dementia, there needs to be a decline from previous level of cognitive functioning not explained by delirium or a psychiatric condition detected by a combination of history taking from the patient and an informant and objective cognitive tests. However, in dementia, the cognitive impairment must be severe enough to impair function and it must include one or more cognitive domains. Of note, memory does not need to be one of the cognitive domains that is impaired.
To determine which cognitive domains are involved, a clinician can review the pattern of errors on an in-office cognitive assessment (e.g., spelling “world” backwards is a test of attention while recalling words is a test of learning and memory). Further, in talking with patients and families, a clinician can categorize the described impairments within domains. For example, getting lost while driving represents a deficit in the perceptual-motor domain, while inability to organize a family dinner likely represents a deficit in executive functioning.
Tools for Screening
Clinicians should consider screening for dementia or MCI in any patient where the patient or caregiver reports trouble with the patient’s thinking or memory. Further, new functional impairment in any of the instrumental activities of daily living may represent new cognitive decline. Instrumental activities of daily living include arranging transportation, managing medications, managing finances, cooking, shopping, communicating on the phone, using the bathroom, laundry, and housework.
Several in-office or bedside screening tools exist for screening of dementia or MCI.4 Perhaps one of the quickest basic screening tests for cognitive impairment is the 3-minute “Mini-Cog.” With this assessment, a clinician lists three words for the patient to remember, asks the patient to draw a clock and set the time as instructed, and then asks the patient to recall the three words. One point is given for each word correctly recalled and two points are given if the clock draw is correct. A score of 2 or less is associated with a high likelihood of significant cognitive impairment. Other commonly used tests include the Mini-Mental State Exam, the Montreal Cognitive Assessment, and the St. Louis Mental Status Exam.
Sharing the Diagnosis
Prior to cognitive testing, it can be helpful to ask the patient and family what they would want to know about the results.1 Some patients and families will want to have a clear diagnosis, while others may ask for more limited information.
If the patient and family have asked for a diagnosis, it is recommended to specifically use the word dementia instead of a vague phrase such as “memory problems.” Pausing after sharing the diagnosis and asking if the patient and family want more information gives them time to process and respond. Many families want to know what to expect in the coming months and what they can do to prepare. Referrals to community-based organizations that offer support and resources for dementia such as the Alzheimer’s Association or an Area Agency on Aging can be helpful for additional guidance.
Conclusion
Primary care SGIM members are on the front line of diagnosing dementia. Monitoring changes in patients’ ability to complete instrumental activities of daily living can identify patients who would benefit from cognitive screening. Many screening tools exist to make a diagnosis of MCI or dementia and detection and sensitive disclosure of a diagnosis of dementia can help patients and families prepare for the future.