Diagnosis of dementia is clinical in nature. Testing is usually done by a specialist, starting with a thorough history, a detailed medical and neurologic examination, and a formal mental status exam including cognitive testing (Chertkow et al., 2013). The goal is to determine if there has been a cognitive change, and if so, whether it indicates the onset of dementia or the presence of a disease, infection, drug interaction, or anything else associated with cognitive change.
Screening is a method for detecting dysfunction before an individual would normally seek medical care. It has the potential to identify very early signs of dementia and identify clients who may need a more thorough cognitive assessment. Screening can also identify changes associated with reversible causes and treat conditions that may contribute to cognitive decline (Yang et al., 2016).
The Affordable Care Act directs clinicians to conduct an assessment of possible cognitive impairment in Medicare patients during their Annual Wellness Visit. Screening usually involves asking patients to perform a series of tasks that assess at least 1 cognitive domain (memory, attention, language, and visuospatial or executive functioning) (USPSTF, 2014).
Although there is no single cognitive assessment tool that is considered as a gold standard (Cordell et al., 2013), a variety of screening tools are available to assess clients for cognitive changes. No one tool is recognized as the best brief assessment to determine if a full dementia evaluation is needed (Alzheimer’s Association, 2017).
The most widely used tools are the Mini Mental State Examination and the Montreal Cognitive Assessment. The Mini Mental State Exam (MMSE) is a 30-point instrument with 11 items that has been studied in various populations. Although sensitivity and specificity vary depending on the patient’s age and education level, a general cut point of 23/24 or 24/25 is appropriate for most primary care populations (USPSTF, 2014).
The Montreal Cognitive Assessment is used most often to assess mild cognitive impairment. It is a 30-point test that assesses short term memory recall, visuospatial abilities, and several aspects of executive function. It takes about 10 minutes to complete with a score of 26 or above considered normal.
Other screening instruments include the Clock Drawing Test, Mini-Cog Test, Memory Impairment Screen, Abbreviated Mental Test, Short Portable Mental Status Questionnaire, Free and Cued Selective Reminding Test, 7-Minute Screen, Telephone Interview for Cognitive Status, and Informant Questionnaire on Cognitive Decline in the Elderly (USPSTF, 2014). For non-clinicians, family, and friends, a mental status screen such as the AD8 Dementia Screening Interview can be useful. This tool looks at whether there has been a change or no change in:
Mini Mental State Examination and the Montreal Cognitive Assessment tests have limitations, namely, they are not very sensitive to mild impairment, particularly in conditions other than Alzheimer’s disease. The MMSE shows education and language/cultural bias (Yang et al., 2016) and both tools are impractical as screening tools because they take at least 10 minutes to complete.
Other limitations of screening tests can be one or more of the following:
Developing an effective dementia screening tool is challenging because the assessment of cognitive deficits is time-consuming and requires specialized knowledge and strong familiarity with neurologic diseases; inaccurate diagnoses are common (Saito et al., 2014). Because of these obstacles, the U.S. Preventive Services Task Force has recommended that, for cognitive impairment in older adults, current evidence is insufficient to assess the balance of benefits and harms of screening for cognitive impairment (USPSTF, 2014).
UCSF Brief Clinical Index
For clinicians, differentiating between the subtle cognitive declines associated with normal aging and those that signify early dementia can be difficult. To help clinicians better understand the progression of Alzheimer’s disease, researchers at the University of California at San Francisco have developed a brief clinical index that they used to predict whether 382 older adults diagnosed with a certain type of mild cognitive impairment would progress to probable Alzheimer’s disease within 3 years. The index utilizes 8 items that are readily obtainable in most clinical settings:
Researchers also used other measures, including demographics, comorbid conditions, caregiver report of participant symptoms and function, and participant performance on individual items from basic neuropsychological scales. In this study, subjects had a mean age of 75 years and 43% progressed to probable Alzheimer’s disease within 3 years.
Important predictors of progression included being female, resisting help, becoming upset when separated from a trusted caregiver, difficulty shopping alone, forgetting appointments, number of words recalled from a 10-word list, orientation, and difficulty drawing a clock. Fourteen percent of subjects with low risk scores converted to probable Alzheimer’s disease over 3 years, compared to 51% of those with moderate risk scores and 91% of those with high risk scores.
Source: Lee et al., 2014
If you are working with a client in an adult day care facility and notice or suspect a change in mental status, try to determine whether your client is operating at a normal level or whether something has changed. If you notice something different in the person’s behavior or demeanor—especially if the change is sudden—report your concerns to the nursing staff immediately. They will assess the client and decide on the next course of action.