52: Evaluating Confusion in Older Adults

Confusion is a common presenting problem in many older patients, but it is not a normal part of aging. Most adults experience some cognitive changes as they age, such as decreases in the speed of processing information, lessened spontaneous recall, and small decreases in executive skills. Confusion, however, is not normal aging. When an older patient presents with confusion, it is important to determine whether the confusion is acute or chronic in nature. For example, is it a recent change (days to weeks) or has the change been more chronic and progressive in nature (months to years)? Sometimes the change will be manifested as an acute or sudden change in behavior, such as increased agitation, aggression, wandering, or falls, or a change in function. Understanding the nature and time line of the events will give you an indication regarding the potential underlying diagnosis.

Knowledge of baseline cognitive and physical functional status are key assessment parameters when evaluating confusion. Gathering baseline cognitive and functional status information from patients as well as caregivers, family, and friends will help you determine if the patient’s confusion represents an acute change as a result of delirium or if the confusion is more chronic and insidious, such as that related to dementia. It is important to note that while confusion is most commonly a symptom of delirium or dementia, it can also be associated with psychoses and affective disorders, specifically major depression.

Delirium

Delirium, often presenting as acute confusion, is a highly prevalent, preventable, life-threatening clinical syndrome in acutely ill older adults. It is characterized by an acute change in cognition and attention, with disturbances in consciousness, orientation, memory, thought, perception and/or behavior. In contrast to dementia, which is a chronic confusional state, delirium typically develops over a short period of time (hours to days), fluctuates over the course of the day (often worsening at night) with varying inability to concentrate, maintain attention, and sustain purposeful behavior. Anxiety, irritability, and psychomotor restlessness with insomnia are common. These patients may pick at their intravenous lines, take off their oxygen, disconnect monitoring equipment, exhibit poor safety awareness, and/or talk to people who are not present. Other perceptual disturbances (often visual hallucinations) are also commonly accompanied by paranoid delusional thinking exacerbating the patient’s behavioral and emotional manifestations. Agitated behaviors commonly associated with delirium often lead to use of physical and chemical restraints, further compounding the risk of functional loss and serious complications.

Family and caregivers may report the patient was “fine” during the day, but became confused, restless, and agitated during the middle of the night. The change, however, may be even more subtle: “She isn’t acting quite right.” When family and caregivers can pinpoint such a subtle change over the course of a day or week, that should be taken seriously, and delirium should be ruled out. Delirium is considered a medical emergency and should always be ruled out prior to assuming the patient only has dementia or another psychiatric disorder.

Dementia

Unlike delirium, dementia is more chronic in nature and develops insidiously over months to years. Specifically, dementia is a clinical syndrome characterized by a cluster of signs and symptoms including difficulties in memory, disturbances in language, psychological and psychiatric changes, and impairments in activities of daily living. Although there are many different types of dementia (see Chapter 22, “Cognitive Impairment & Dementia”), Alzheimer disease is the most common cause, occurring in an estimated 50% to 80% of all cases.

Such a dementia typically first appears as forgetfulness of recent events or conversations. Family and loved ones may report that over the past several months or year the patient has been increasingly getting lost in familiar areas; misplacing items; having language difficulties (eg, finding the name of familiar objects); having problems performing tasks that require some thought, but that used to come easily (eg, balancing a checkbook, playing card games, learning new information or routines); and/or experiencing personality changes or a loss of social skills leading to inappropriate behaviors. As the dementia slowly progresses, these symptoms become much more apparent and severe, and interfere with the patient’s ability to care for him-/herself. Patients may also begin to exhibit psychosis, mood and behavioral difficulties (eg, paranoid delusions, hallucinations, depression, physical and/or verbal aggression; social withdrawal), or sleep disturbances (eg, often waking at night), with increasingly poor insight and judgment. Many of these behaviors often present significant caregiving challenges and burden, frequently resulting in institutionalization. In the severe stages, patients are unable to perform basic activities of daily living, recognize family members, understand language, speak, or ambulate independently.

It is important to note that confusion or a decline in cognitive functioning that is abnormal for age and education but does not meet criteria for dementia should not be attributed to normal aging. Mild cognitive impairment (MCI) is the intermediate-stage neurocognitive disorder between normal cognitive aging and dementia. MCI is associated with an increased lifetime risk for developing dementia. A person with MCI will have problems with memory, language, or another mental function severe enough to be noticeable to others and show up on testing, but not serious enough to interfere with daily life. Understanding the degree of functional incapacitation is a key component to determining whether the person has MCI or early dementia.

Depression

Depression is the most common psychiatric disorder in the older adult population, primarily affecting those with chronic medical illnesses, cognitive impairment, and disability. It is clinically defined as a syndrome of either depressed mood or loss of interest or pleasure in most activities of the day and these symptoms must represent a change from the person’s usual functioning and be present for at least 2 weeks. Personality changes (eg, social withdrawal, apathy, irritability), forgetfulness, and mood changes (eg, complaints of decreased ability to think, feelings of hopelessness/helplessness, changes in sleep or appetite, psychomotor slowing/agitation) may be signs of depression, dementia, or both. Patients with depression may recognize their feelings of sadness, experience somatic complaints or simply exhibit decreased engagement in activities of daily living. The mnemonic “SIGECAPS” (Table 52–1) can help you remember the 8 major diagnostic symptoms of depression.

Unlike dementia, confusion in a patient with depression is more specific than global. For example, the patient may have difficulties with certain activities, like paying bills, but remains capable of completing equally difficult tasks, such as doing a crossword puzzle. Similarly, the patient may not initiate or engage in conversation, but retains the ability to speak. A person with depression is also more likely to relate many themes of loss, as well as detail their cognitive complaints, whereas someone with dementia may be unaware of their cognitive difficulties and/or try to mask their deficits.

When a patient presents with confusion, it is critical to perform a detailed history and in-depth physical exam, including a mental status exam, as well as laboratory and diagnostic tests. Interviewing the family/caregiver, as well as the patient, is also critical to better understanding the nature and course of the patient’s confusion.

History and Physical Exam

A thorough history should focus on the specific cognitive, functional and behavioral changes, how these symptoms have evolved over time, and symptoms that may link them to medical, neurologic or psychiatric conditions. Table 52–2 details key additional past history domains to assess. The medical evaluation should incorporate data from the psychosocial assessment, review of medications (including nonprescription/complementary alternative therapies), and include a complete physical examination with laboratory and diagnostic studies. The general physical exam should focus on the cardiovascular, neurologic and psychiatric systems, unless otherwise indicated by the patient’s history.

Mental Status Exam

Mental status should be assessed in the domains of memory, abstract thinking, judgment, mood/affect, orientation, attention or concentration, level of consciousness (wakefulness or sleepiness), communication or language abilities, and personality changes (eg, suspiciousness or loss of impulse control). Standardized mental status questionnaires, diagnostic rating scales and symptom inventories can also assist in this assessment process. Together with the history and physical examination, instruments such as the Montreal Cognitive Assessment (MOCA), Confusion Assessment Method (CAM; Table 52–3) and Geriatric Depression Scale (GDS), can aid the clinician in differentiating among dementia, delirium and depression. Recognize, however, that the results of these tools cannot be interpreted in isolation. Assessment findings must be interpreted within the context of an individual’s socioeconomic status, cultural background, education and literacy level, current/previous occupation, and other psychosocial factors.

In addition, the way patients respond to these standardized assessment instruments is just as critical as the score they achieve. For example, a patient with depression may perform poorly on the MOCA as a result of poor effort, apathy, and frequent answers of “I don’t know,” whereas someone with dementia may put forth great effort, attempt to rationalize mistakes, and/or feel bad if they are unable to answer questions appropriately. Alternatively, someone with delirium may exhibit poor attention and concentration by being easily distracted and/or falling asleep during the assessment process. Table 52–4 presents a comparison of the key diagnostic features to help differentiate delirium, dementia, and depression.

Initial laboratory tests should include blood chemistry panel, complete blood count, thyroid panel, liver function, vitamin B₁₂, and serum drug levels (eg, digoxin). Structural neuroimaging with CT scanning or MRI is recommended in the assessment of patients with dementia and may be beneficial in the assessment of MCI. An electroencephalogram may be indicated if there is any suggestion of seizure activity or to help differentiate delirium from a psychiatric disorder. Additional lab and diagnostic tests are based on individual presentation, other medical co-morbidity, and findings from the history and physical examination.

Finally, it is important to recognize that when evaluating confusion in an older adult the 3 common clinical syndromes (ie, dementia, delirium, depression) may overlap. For example, between 25% and 75% of patients with delirium have coexisting dementia and the presence of dementia increases the risk of delirium up to 5-fold. Depression also often coexists with dementia in approximately 20% of individuals with Alzheimer disease and is associated with higher levels of functional impairment and reduced enjoyment in activities. In addition, late-life depressive symptoms or syndromes may be an early manifestation of cognitive decline and dementing disorders in older adults. Moreover, there is a syndrome of overlapping depression and delirium that is associated with significant risk of functional decline, institutionalization, and death. Thus, it is critical to be able to recognize and evaluate all 3 syndromes and their complex interplay in order to safely and effectively provide care to older adults presenting with confusion.