Am Fam Physician. 2003;68(9):1848-1850
Memory loss is common in older adults and is usually noted by either the adults or their family members and friends. Persons with clinically meaningful memory loss usually show delayed recall or impaired ability to remember recently learned information. Another consideration in patients with memory loss is a problem in another cognitive area that manifests as a memory problem. Language impairment or inattention related to depression are two of a number of causes that may present as memory problems. Karlawish and Clark reviewed the evaluation of older adults with mild memory complaints.
Normal aging resulting in frontal lobe decline can cause memory lapses, but performance of daily activities is not impaired. Mild cognitive impairment, with symptoms falling between those of normal aging and those of dementia, may represent a predementia state, with an increased likelihood of progression to Alzheimer’s disease.
Memory loss that impairs function suggests neurodegenerative dementia, which is defined as a decline in two or more cognitive domains. Common causes of dementia include, in order of likelihood, Alzheimer’s disease, frontotemporal dementia, and dementia with Lewy bodies. Early Alzheimer’s disease manifests as problems with retaining new information and difficulty with cueing to help jog the memory. Social withdrawal or other mood or behavior changes can begin mildly and may reflect difficulties in dealing with an unfamiliar environment. Disease progression is characterized by word hesitancy and circumlocutions, although language comprehension is less impaired.
The evaluation of memory problems starts with a history focused on changes in the patient’s ability to perform instrumental activities of daily living. These activities, such as shopping, cooking, managing money, using the telephone, and taking medications, are good indicators of cognitive function. Interviewing a knowledgeable informant helps the physician determine the nature and severity of the patient’s impairments. Physicians should use judgment in assessing this information so the impairment is not overestimated or underestimated.
Useful methods of assessment include closer observation by a family member or friend and a brief, standardized cognitive and affective test using an abbreviated set of questions (see accompanying table on page 1850) or the Mini-Mental State Examination. Use of a depression scale can help screen for concomitant depression. Treatment of depression might improve functional status, although antidepressants with anticholinergic side effects that could worsen cognitive function should be avoided.
| Domain of cognition | Clinical tests that can identify impairment | Administration and scoring | |
|---|---|---|---|
| 1. Orientation to date | Recite month, year, day of week, date, season (useful warm-up for the other cognitive tests). | At the change of seasons, allow a leeway of one week. Marked errors in orientation (i.e., incorrect month or year) strongly suggest cognitive impairment. | |
| 2. Registration. | Repeat a list of common nouns (e.g., apple, table, penny). | Ask the patient to repeat a list of words after you recite them. Repeat the list up to three times, until registration is complete. The need for list repetition suggests errors in language, attention, or working memory. To minimize the effects of education, the words should be common nouns | |
| 3. Visuospatial and executive function | Draw a clock set at 8:20 and make it big enough that a child can read it. | The directions should be repeated in full if the patient asks for them. Scoring should consider the positioning of the numbers and the hands, and how much effort it takes to accomplish the task. | |
| Copy a figure of interlocking pentagons. | A correct figure should contain 10 angles and four intersecting sides. | ||
| 4. Language | Recite the names of as many animals as possible in 60 seconds. (This test also assesses working memory and executive functioning.) | An abnormal score is naming fewer than 10 animals. Avoid stating the time limit because this can cause performance anxiety. Instead, tell the patient, “I’ll tell you when to start and when to stop.” | |
| 5. Attention and working memory | Spell “world” backward. | “World” should be spelled forward and any errors corrected before the patient attempts to spell it backward. Count one error for each letter omission, transposition, insertion, or misplacement. | |
| 6. Memory | Recall the list of words used in the registration task. | The interval between registration and recall should include performing cognitive tests 3 through 5. |
In the physical examination, the physician should evaluate the patient for focal neurologic deficits that may represent vascular dementia, gait disorder (parkinsonism) with or without altered levels of alertness, and visual hallucinations that may suggest dementia with Lewy bodies, or frontal and behavior signs that suggest frontotemporal dementia. Diagnostic testing should include a complete blood count, basic blood chemistries, thyroid function testing, and determination of the vitamin B12 level. As cognitive function deteriorates, magnetic resonance imaging is appropriate to distinguish vascular etiologies from other causes. The clinical significance of cortical atrophy is unclear.
Treatment of dementia is based on the cause and the impact of the cognitive changes. Patients with Alzheimer’s disease may benefit from vitamin E and a cholinesterase inhibitor to slow disease progression. Arrangements should be made to lessen the negative impact of cognitive declines by enlisting the help of family members and support organizations. Other issues that should be addressed include caregiver’s needs, changes in treatment, and placement in a long-term care facility, when required.
In the same journal, Clark and Karlawish review diagnostic and therapeutic strategies for Alzheimer’s disease. They discuss the ongoing development of diagnostically specific biomarkers and new treatments.