Topic Resources
In the primary care setting, memory loss is commonly reported. It is particularly common among older adults but also may be reported by younger people. Sometimes family members rather than the patient report the memory loss (typically in an older adult with dementia).
Clinicians and patients are often concerned that the memory loss indicates impending dementia. Such concern is based on the common knowledge that the first sign of dementia typically is memory loss. However, most memory loss does not represent the onset of dementia.
The most common and earliest complaints of memory loss usually involve:
Difficulty remembering names and the location of car keys or other commonly used items
As memory loss becomes more severe, people may not remember to pay bills or keep appointments. People with severe memory loss may have dangerous lapses, such as forgetting to turn off a stove, to lock the house when leaving, or to keep track of an infant or child they are supposed to watch. Other symptoms (eg, depression, confusion, personality change, difficulty with activities of daily living) may be present, depending on the cause of memory loss.
Etiology of Memory Loss
The most common causes of memory loss (see table Characteristics of Common Causes of Memory Loss) are:
Age-associated memory impairment (most common)
Mild cognitive impairment
Dementia
Depression
Age-associated memory impairment refers to the worsening of memory that occurs with aging. In people with this condition, it takes longer to form new memories (eg, a new neighbor's name, a new computer password) and to learn complex information and tasks (eg, work procedures, computer programs). Age-associated memory impairment leads to occasional forgetfulness (eg, misplacing car keys) or embarrassment. However, cognition and the ability to perform most activities of daily living are not impaired. Given sufficient time to think and answer questions, people with this condition can usually do so, indicating intact memory and cognitive functions.
Patients with mild cognitive impairment have actual memory loss, rather than occasional slow memory retrieval from relatively preserved memory storage. Mild cognitive impairment tends to affect short-term (also called episodic) memory first. Patients have trouble remembering recent conversations, the location of commonly used items, and appointments. However, memory for remote events is typically intact, as is attention (also called working memory—patients can repeat lists of items and do simple calculations). The definition of mild cognitive impairment is evolving; mild cognitive impairment is now sometimes defined as impairment in memory and/or other cognitive functions that is not severe enough to affect daily function. Patients with mild cognitive impairment are at increased risk for developing dementia but, depending on the population studied, there is much variation in risk estimates, ranging from < 5% to 20% annual conversion rates (1).
Patients with dementia have memory loss plus evidence of cognitive and behavioral dysfunction. For example, they may have difficulty with finding words and/or naming objects (aphasia), doing previously learned motor activities (apraxia), or planning and organizing everyday tasks, such as meals, shopping, and bill paying (impaired executive function). Their personality may change; for example, they may become uncharacteristically irritable, anxious, agitated, and/or inflexible.
Depression is common among patients with dementia. However, depression itself can cause memory loss that simulates dementia (pseudodementia). Such patients usually have other features of depression.
Delirium is an acute confusional state, which may be caused by a severe infection, a medication (adverse effect) or drug, or medication or drug withdrawal. Patients with delirium have impaired memory, but the main reason they present is usually severe, fluctuating global changes in mental status (primarily in attention) and cognitive dysfunction, not memory loss.
Characteristics of Common Causes of Memory Loss
Cause | Suggestive Findings | Diagnostic Approach* |
|---|---|---|
Age-associated memory impairment | Occasional forgetfulness (eg, of names or location of car keys) but no other impairment of memory Normal cognitive function | History and physical examination alone |
Mild cognitive impairment | Memory impaired Daily function not affected Other aspects of cognition intact | History and physical examination Sometimes neuropsychiatric testing |
Memory impaired Daily function affected (eg, finding their way around the neighborhood, doing usual tasks at work) Impairment of at least 1 other aspect of cognition:
| History and physical examination Brief neurocognitive testing (eg, Montreal cognitive assessment or MOCA) Sometimes neuropsychiatric testing To identify causes: MRI or CT, lumbar puncture, blood tests | |
Memory loss often correlated with severity of mood disturbance Sometimes sleep disturbance, loss of appetite, psychomotor slowing Often present in patients with dementia, mild cognitive impairment, or age-associated memory impairment Memory loss is usually short-term and may be due to lack of concentration or easy distraction related to anxiety and depression | Clinical examination alone Use of patient questionnaires (eg, Beck Depression Inventory) | |
Medication and drug use (eg, of anticholinergic medications, antidepressants, opioids, psychoactive agents, or sedatives) | Use of causative medication or substance Often recent initiation of medication therapy, an increase in dose, or slowing of clearance (eg, caused by decrease in renal or liver function) | Typically a trial of stopping or changing the suspected causative medication or substance |
* Clinical examination is always done but is mentioned in this column only when that can be the sole means of diagnosis | ||
Less common causes of memory loss that may be reversed with treatment include the following:
Depression (can cause pseudodementia)
Neurosarcoidosis
Other disorders may be remediable, depending on the extent and degree of tissue damage. They include:
Unusually long seizures or non-convulsive status epilepticus
Certain types of stroke
Overuse of certain medications and other substances (including alcohol)
Brain infections may be viral (eg, HIV, herpes encephalitis, progressive multifocal leukoencephalopathy) or related to prions (eg, Creutzfeld-Jacob disease).
Etiology reference
1. Langa KM, Levine DA.The diagnosis and management of mild cognitive impairment: a clinical review. JAMA 312(23):2551–2561, 2014. doi:10.1001/jama.2014.13806
Evaluation of Memory Loss
The highest priority when evaluating memory loss is:
To identify reversible causes, including depression, anxiety, hypothyroidism, and delirium, which require rapid treatment
The evaluation then focuses on distinguishing the few cases of mild cognitive impairment and early dementia from the greater number with age-associated memory impairment or simply normal forgetfulness.
Full evaluation for dementia usually requires more time than is commonly allotted for a routine office visit. However, the Montreal Cognitive Assessment (MOCA) is a brief screening test that can be done in less than 10 minutes (1). Evaluation by a neuropsychologist may be additionally helpful if the MOCA is abnormal and the diagnosis is uncertain.
History
History should, when possible, be taken from the patient and family members separately. Cognitively impaired patients may not be able to provide a detailed, accurate history, and family members may not feel free to give a candid history with the patient listening.
History of present illness should include a description of the specific types of memory loss (eg, forgetting words or names, getting lost, short- or long-term memory difficulties) and their onset, severity, and rapidity of progression. Clinicians should determine how much symptoms affect day-to-day function at work and at home. Important associated findings involve changes in language use, eating, sleeping, and mood. Clinicians should also evaluate whether the patient has the mental capabilities for operating a motor vehicle, because some jurisdictions require clinicians to report patients with impaired driving capabilities to local licensing authorities.
Review of systems should identify neurologic symptoms and other factors that may suggest a specific type of dementia, such as the following:
Parkinsonian symptoms and hallucinations in Lewy body dementia
Focal neurologic deficits in vascular dementia
Head trauma (eg, due to a recent fall) suggesting subdural hematoma
Inability to look upward or downward and falling backward in progressive supranuclear palsy
Choreiform movements in Huntington disease
Gait disturbance and urinary incontinence in normal-pressure hydrocephalus
Low energy, dry skin, and weight gain in hypothyroidism
Balance problems and difficulty with fine motor movements in vitamin B12 deficiency
A history of repeated events, with or without some recovery, suggestive of neuroinflammatory conditions such as multiple sclerosis or neurosarcoidosis
Past medical history should include known disorders and a complete history of all prescription (especially immune-compromising therapies), over-the-counter, and illicit drugs used.
Family and social histories should include the patient's baseline levels of intelligence, education, employment, and social functioning. Previous and current substance abuse is noted. Family history of dementia or early mild cognitive impairment is queried. Social history should also include unusual dietary habits.
Physical examination
In addition to a general examination, a complete neurologic examination is done, with detailed mental status testing.
Mental status testing assesses the following components, by asking the patient to do certain tasks:
Orientation (give their name, the date, and their location)
Attention and concentration (eg, repeat a list of words, do simple calculations, spell "world" backwards)
Short-term memory (eg, repeat a list of 3 or 4 items after 5, 10, and 30 minutes)
Long-term memory (eg, answer questions about the distant past)
Language (eg, name common objects)
Praxis and executive function (eg, follow a multiple-stage command)
Constructional praxis (eg, copy a design or draw a clock face)
Reading
Calculation
The examination should also include assessment of primitive reflexes (eg, glabellar tap, palmomental response) that are frontal lobe release signs that often occur in dementia disorders.
Various scales can be used to screen for impairment in these components. A common way to screen is with the Montreal Cognitive Assessment (1) or the Folstein Mini-Mental Status Examination (2).
Red flags
In patients with memory loss, the following findings are of particular concern:
Impaired daily function
Loss of attention or altered level of consciousness
Symptoms of depression (eg, loss of appetite, psychomotor slowing, suicidal ideation)
Speed of symptom onset
Memory loss that develops rapidly may indicate a disorder such as Creutzfeldt-Jakob disease (CJD) or a brain tumor.
Interpretation of findings
The presence of actual memory loss and impairment of daily function and other cognitive functions help differentiate age-related memory changes, mild cognitive impairment, and dementia.
Mood disturbance is present in patients with depression but is also common in patients with dementia or mild cognitive impairment. Thus, differentiating depression from dementia can be difficult until memory loss becomes more severe or unless other neurologic deficits (eg, aphasia, agnosia, apraxia) are evident.
Inattention helps differentiate delirium from early dementia. Memory loss is unlikely to be the presenting symptom in most patients with delirium. Nonetheless, delirium must be excluded before a diagnosis of dementia is made.
One particularly helpful clue to distinguish age-associated memory impairment from dementia is how the patient came to medical attention. If the patient initiates the medical evaluation because of worries about becoming forgetful, age-associated memory impairment is the likely cause. If a family member initiates a evaluation and the patient is less worried about memory loss than the family is, dementia is more likely than when the patient initiates the evaluation.
Testing
Diagnosis of memory loss is primarily based on history and examination, including a brief mental status examination. However, the accuracy of any brief mental status examination is affected by the patient's intelligence and educational level. For example, patients with high educational levels can score falsely high, and those with low levels can score falsely low. If the diagnosis is unclear, more accurate, formal neuropsychiatric testing can be done; results have higher diagnostic accuracy.
For most patients, serum vitamin B12 measurement, a complete metabolic panel (including serum creatinine, liver tests, calcium, magnesium, and glucose), and thyroid function tests are needed to exclude potentially readily reversible causes of memory impairment.
Neuroimaging with MRI (or CT if MRI is unavailable) is performed in patients with neurologic abnormalities (eg, weakness, altered gait, involuntary movements), rapid symptom onset or evolution, or findings or history suggesting subdural hematoma.
If a medication or substance is the suspected cause, it can be stopped or another medication substituted as a diagnostic trial.
Treating apparently depressed patients may facilitate differentiation between depression and mild cognitive impairment.
Evaluation references
1. Nasreddine ZS, Phillips NA, Bédirian V, et al: The Montreal Cognitive Assessment, MoCA: A brief screening tool for mild cognitive impairment. J Am Geriatr Soc 53 (4):695–699, 2005. doi: 10.1111/j.1532-5415.2005.53221.x
2. Folstein MF, Folstein, McHugh PR: "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 12 (3):189–198, 1975. doi: 10.1016/0022-3956(75)90026-6
Treatment of Memory Loss
Patients with age-associated memory impairment should be reassured. Some generally healthful measures are often recommended to help maintain function and possibly decrease the risk of dementia.
Patients with depression and memory loss are treated with medications and/or psychotherapy. Nonanticholinergic antidepressants, and preferably selective serotonin reuptake inhibitors (SSRIs), are advised. If depression is the underlying condition, memory loss tends to resolve as depression does.
Delirium is treated by correcting the underlying condition.
Rarely, dementia is reversible with a specific treatment (eg, supplementary vitamin B12, thyroid hormone replacement, shunting for normal-pressure hydrocephalus).
Other patients with memory loss are treated supportively.
General measures
The following can be recommended for patients who are worried about memory loss:
Regular exercise
Consumption of a healthy diet with lots of fruits and vegetables
Sufficient sleep
Not smoking
Minimized use of alcohol or other psychoactive substances (eg, marijuana)
Participation in social and intellectually stimulating activities
Regular physical examinations
Stress management
Prevention of head injury
These measures, with control of blood pressure, cholesterol levels, and plasma glucose levels, also reduce the risk of cardiovascular disorders. Some evidence suggests that these measures may reduce risk of dementia (1).
Some experts recommend:
Learning new things (eg, a new language, a new musical instrument)
Doing mental exercises (eg, memorizing lists; doing word puzzles; playing chess, bridge, or other games that use strategy)
Reading
Working on the computer
Doing crafts (eg, knitting, quilting)
These activities may help maintain or improve cognitive function, possibly because they strengthen neuronal connections and promote new connections.
Patient safety
Occupational and physical therapists can evaluate the home of impaired patients for safety with the goal of preventing falls and other accidents. Protective measures (eg, hiding knives, disabling the stove, removing the car, confiscating car keys) may be required. If patients wander, signal monitoring systems can be installed, or patients can be registered in a safe return program.
Clinicians should know their role in notifying local licensing authorities about patients with dementia; requirements for reporting vary by state (in the United States) and by country.
Ultimately, assistance (eg, housekeepers, home health aides) or a change of environment (eg, living facility without stairs, assisted-living facility, skilled nursing facility) may be indicated.
Environmental measures
Environmental measures can help patients with progressive memory loss or dementia.
Patients with dementia usually function best in familiar surroundings, with frequent reinforcement of orientation (including large calendars and clocks), a bright, cheerful environment, and a regular routine. The room should contain sensory stimuli (eg, radio, television, night-light).
In institutions, staff members can wear large name tags and repeatedly introduce themselves. Changes in surroundings, routines, or people should be explained to patients precisely and simply, omitting nonessential procedures.
Frequent visits by staff members and familiar people encourage patients to remain social. Activities can help; they should be enjoyable and provide some stimulation but not involve too many choices or challenges. Exercises to improve balance and maintain cardiovascular tone can also help reduce restlessness, improve sleep, and manage behavior. Occupational therapy and music therapy help maintain fine motor control and provide nonverbal stimulation. Group therapy (eg, reminiscence therapy, socialization activities) may help maintain conversational and interpersonal skills.
Medications
Eliminating or limiting medications with central nervous system (CNS) activity often improves function. Sedating and anticholinergic drugs tend to worsen dementia and should be avoided.
A number of different classes of medications are available for treatment of patients with Alzheimer disease, and some may be useful in other forms of dementia. Medication options include cholinesterase inhibitors (donepezil, rivastigmine, and galantamine); memantine (an NMDA [N-methyl-A number of different classes of medications are available for treatment of patients with Alzheimer disease, and some may be useful in other forms of dementia. Medication options include cholinesterase inhibitors (donepezil, rivastigmine, and galantamine); memantine (an NMDA [N-methyl-d-aspartate] antagonist), and anti-amyloid monoclonal antibody therapy. The choice of medication depends on several factors, including patient response, adverse effects, and cost.
Some medications, such as cholinesterase inhibitors are modestly effective in improving symptoms of impaired cognitive function in patients with mild to moderate Alzheimer disease or dementia with Lewy bodies and may be useful in other forms of dementia. Efficacy wanes over time. Other medications, such as monoclonal antibodies, aim to modify disease progression by reducing beta-amyloid plaques in the brain in patients with Alzheimer disease. See Treatment of Alzheimer Disease for a detailed discussion of medications used in the treatment of Alzheimer disease.
Treatment reference
1. Livingston G, Huntley J, Sommerlad A, et al: Dementia prevention, intervention, and care: 2020 report of the Lancet Commission [published correction appears in Lancet 2023 Sep 30;402(10408):1132. doi: 10.1016/S0140-6736(23)02043-3]. Lancet 396(10248):413–446, 2020. doi:10.1016/S0140-6736(20)30367-6
Key Points
Memory loss and dementia are common in older adults and are common sources of worry for them.
Age-associated memory impairment is common, causing slowing, but not deterioration, of memory and cognition.
Diagnose primarily based on clinical criteria, particularly mood, attention, presence of true memory loss, and effect on daily function.
Promptly exclude possible reversible and treatable causes of dementia (certain types of stroke, depression, seizures, head trauma, brain infections, hypothyroidism, HIV infection, normal-pressure hydrocephalus, brain tumors, vitamin B12 deficiency, overuse of certain medications and substances including alcohol).
A complete medication and substance use history is critical because sedating and anticholinergic medications can cause memory loss that can be reversed by stopping the medication.
If patients have neurologic abnormalities (eg, weakness, altered gait, involuntary movements), do MRI or CT.
Self-reported memory loss is usually not due to dementia.
Delirium and depression must be excluded before diagnosing dementia.
More Information
The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
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