Subjective Cognitive Impairment: When to Be Concerned about 'Senior Moments': Thorough Evaluation Can Differentiate Benign Memory Problems from Dementia

Article excerpt

Ms. F, age 66, requests genetic testing because she is concerned about mild memory difficulties, such as forgetting names and where she puts her keys or checkbook, and fears she may be developing Alzheimer's disease (AD). Her mother and sister were diagnosed with AD in their early 60s. Ms. F has 20 years of education and reports no problems with driving, managing her finances, remembering to take her medications, or maintaining social activities, which her husband confirms.

Detailed questioning about anxiety and depressive symptoms reveals substantial worries about future cognitive decline and some concerns about her finances and her husband's health. Ms. F says she occasionally feels down and has low energy but denies other depressive symptoms. She reports no sleep disturbances--including snoring and daytime sleepiness, which could indicate obstructive sleep apnea--which her husband confirms. Ms. F takes levothyroxine for hypothyroidism, atenolol for hypertension, aspirin and clopidogrel for coronary artery disease, and atorvastatin for hyperlipidemia. In addition, she provides a long list of over-the-counter (OTC) supplements--ginkgo, huperzine, ginseng, phosphatidylserine, B1, B12, folate, vitamin D, alpha-lipoic acid, and vinpocetine--that she takes to "protect" her brain from AD.

Subjective cognitive impairment (SCI) in older persons is a common condition with a largely unclear prognosis. Many older adults (age [greater than or equal to] 65) express concern about mild cognitive problems--"senior moments"--such as word-finding difficulties and forgetfulness. (1) Individuals may wonder if walking into a room only to forget why might be the first sign of dementia. Some older adults try to counteract these memory problems by engaging in brain exercises--including costly computer games--and taking OTC "brain-enhancing" vitamins, herbal remedies, and other supplements.

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Although some clinicians may view SCI as benign, that is not always true (Table 1). (2-5) This article discusses the clinical significance of these mild cognitive complaints by examining:

* age-related cognitive decline (ARCD)

* SCI

* how SCI can be differentiated from more serious conditions, such as mild cognitive impairment (MCI) and early stages of AD and other dementias.

Table 1

Why SCI should be taken seriously

SCI may create emotional distress because patients are aware of decline in their 'mental sharpness'

SCI patients might consume unnecessary and potentially harmful OTC supplements touted to promote memory

Patients might limit their driving and financial management to avoid making mistakes

SCI might impair medication adherence (2)

SCI may be an early sign of dementia (3)

Patients' worry about their self-perceived memory loss might predict dementia (4)

SCI may predict nursing home placement (5)

Addressing SCI gives health care providers an opportunity to address anxiety or depression that often accompany SCI

Evaluation of potential causes of SCI may uncover reversible conditions that can be treated

OTC: over-the-counter; SCI: subjective cognitive impairment

We also will discuss assessing and treating cognitive complaints. Although distinctions between SCI and ARCD may be controversial, evidence suggests clinicians need to adopt a more nuanced clinical approach.

'Normal' cognitive decline

ARCD is subtle decline in cognitive abilities, such as episodic memory, attention, and time needed to complete complex activities. (6), (7) Individuals with ARCD might not have subjective memory complaints or objective cognitive deficits, and their ability to live independently may not be compromised.7 The degree of decline in ARCD may be smaller than previously thought.(8) Park (9) summarizes 4 main mechanisms thought to underlie age-related declines in cognition:

* reduced speed of processing

* decreased working memory capabilities

* declining inhibitory control (eg, impaired complex attentional capabilities)

* sensory changes (eg, visual and auditory deficits). …